{"id":18386,"date":"2026-07-19T03:33:52","date_gmt":"2026-07-18T18:33:52","guid":{"rendered":"https:\/\/genai-ai.co.jp\/ai-kanri\/?p=18386"},"modified":"2026-07-19T03:33:52","modified_gmt":"2026-07-18T18:33:52","slug":"cc-java-interface","status":"publish","type":"post","link":"https:\/\/genai-ai.co.jp\/ai-kanri\/blog\/cc-java-interface\/","title":{"rendered":"\u30102026\u5e747\u6708\u6700\u65b0\u3011Java\u306einterface\u3068\u306f\uff1f\u4f7f\u3044\u65b9\u30fb\u5b9f\u88c5\u65b9\u6cd5\u30fb\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3092\u30b3\u30fc\u30c9\u4f8b\u4ed8\u304d\u3067\u5b8c\u5168\u89e3\u8aac"},"content":{"rendered":"\n<style>\n.g-flow-row{display:flex;gap:8px;justify-content:center;flex-wrap:wrap;align-items:center;}\n.g-flow-item{background:linear-gradient(135deg,#1a1a1a,#2a1015);color:#fff;border-radius:8px;padding:16px 14px;min-width:130px;flex:1;text-align:center;}\n.g-flow-arrow{color:#dc2626;font-size:20px;font-weight:700;}\n.g-card-row{display:flex;gap:12px;flex-wrap:wrap;margin:0 0 32px;}\n.g-card-row>div{flex:1;min-width:220px;}\n@media(max-width:600px){\n  .g-flow-row{flex-direction:column;}\n  .g-flow-arrow{transform:rotate(90deg);}\n  .g-card-row{flex-direction:column;}\n  .g-card-row>div{min-width:100%;}\n}\n<\/style>\n\n\n\n<div style=\"margin:0 0 32px;\">\n  <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/07\/thumb-cc-java-interface-2.jpg\" alt=\"\u30102026\u5e747\u6708\u6700\u65b0\u3011Java\u306einterface\u3068\u306f\uff1f\u4f7f\u3044\u65b9\u30fb\u5b9f\u88c5\u65b9\u6cd5\u30fb\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3092\u30b3\u30fc\u30c9\u4f8b\u4ed8\u304d\u3067\u5b8c\u5168\u89e3\u8aac\" style=\"width:100%;height:auto;border-radius:12px;display:block;\">\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u300cJava\u306einterface\u3063\u3066\u4f55\u306e\u305f\u3081\u306b\u3042\u308b\u306e\uff1f\u300d\u300cimplements\u3068extends\u306f\u3069\u3046\u9055\u3046\uff1f\u300d\u2014\u2014Java\u3092\u5b66\u3073\u59cb\u3081\u308b\u3068\u3001\u5fc5\u305a\u3076\u3064\u304b\u308b\u7591\u554f\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">interface\u306fJava\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u30d7\u30ed\u30b0\u30e9\u30df\u30f3\u30b0\u306b\u304a\u3051\u308b<strong>\u6700\u91cd\u8981\u306e\u8a2d\u8a08\u6982\u5ff5\u306e\u4e00\u3064<\/strong>\u3067\u3059\u3002\u6b63\u3057\u304f\u7406\u89e3\u3059\u308c\u3070\u3001\u4fdd\u5b88\u6027\u304c\u9ad8\u304f\u62e1\u5f35\u3057\u3084\u3059\u3044\u30b3\u30fc\u30c9\u304c\u66f8\u3051\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002\u3057\u304b\u3057\u300c\u306a\u3093\u3068\u306a\u304f\u52d5\u3044\u3066\u3044\u308b\u300d\u72b6\u614b\u3067\u306f\u3001\u30c1\u30fc\u30e0\u958b\u767a\u3067\u5927\u304d\u306a\u30c8\u30e9\u30d6\u30eb\u306e\u539f\u56e0\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001interface\u306e\u57fa\u790e\u6982\u5ff5\u304b\u3089\u5b9f\u969b\u306e\u30b3\u30fc\u30c9\u4f8b\u3001\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3001default\u30e1\u30bd\u30c3\u30c9\u30fbstatic\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u65b9\u3001\u305d\u3057\u3066\u591a\u91cd\u7d99\u627f\u306e\u5b9f\u73fe\u307e\u3067\u3001<strong>\u521d\u5fc3\u8005\u3067\u3082\u8ff7\u308f\u306a\u3044\u3088\u3046\u6bb5\u968e\u7684\u306b\u89e3\u8aac<\/strong>\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<div class=\"balloon-wrap\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/ceo-sugasawa.jpg\" alt=\"\u4ee3\u8868\u83c5\u6fa4\">\n    <span class=\"balloon-name\">\u4ee3\u8868\u83c5\u6fa4<\/span>\n  <\/div>\n  <div class=\"balloon-body\">interface\u3092\u300c\u306a\u3093\u3068\u306a\u304f\u4f7f\u3063\u3066\u3044\u308b\u300d\u6bb5\u968e\u304b\u3089\u300c\u8a2d\u8a08\u306e\u9053\u5177\u3068\u3057\u3066\u4f7f\u3044\u3053\u306a\u3059\u300d\u6bb5\u968e\u306b\u4e0a\u3052\u308b\u3053\u3068\u304c\u3001\u3053\u306e\u8a18\u4e8b\u306e\u76ee\u6a19\u3067\u3059\u3002Java\u672a\u7d4c\u9a13\u306e\u65b9\u306f\u6700\u521d\u304b\u3089\u3001\u3042\u308b\u7a0b\u5ea6\u89e6\u3063\u305f\u3053\u3068\u304c\u3042\u308b\u65b9\u306fH2\u300c\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u300d\u304b\u3089\u8aad\u307f\u59cb\u3081\u308b\u3053\u3068\u3092\u304a\u3059\u3059\u3081\u3057\u307e\u3059\u3002<\/div>\n<\/div>\n\n\n\n<p class=\"wp-block-paragraph\">\u3053\u306e\u8a18\u4e8b\u3092\u8aad\u3080\u3068\u308f\u304b\u308b\u3053\u3068\uff1a<\/p>\n\n\n<ul style=\"list-style:none;padding:0;margin:16px 0\"><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Java\u306einterface\u3068\u306f\u4f55\u304b<\/strong>\u2014\u2014\u305d\u306e\u6982\u5ff5\u3068\u5b58\u5728\u610f\u7fa9<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>interface\u306e\u66f8\u304d\u65b9\u3068implements\u306b\u3088\u308b\u5b9f\u88c5\u65b9\u6cd5<\/strong>\u2014\u2014\u30b3\u30fc\u30c9\u4f8b\u4ed8\u304d<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>\u62bd\u8c61\u30af\u30e9\u30b9\uff08abstract class\uff09\u3068\u306e\u9055\u3044<\/strong>\u2014\u2014\u4f7f\u3044\u5206\u3051\u306e\u5224\u65ad\u57fa\u6e96<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>default\u30e1\u30bd\u30c3\u30c9\u3068static\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u65b9<\/strong>\u2014\u2014Java 8\u4ee5\u964d\u306e\u65b0\u6a5f\u80fd<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>\u8907\u6570interface\u306e\u5b9f\u88c5\uff08\u591a\u91cd\u7d99\u627f\uff09<\/strong>\u2014\u2014Java\u3067\u591a\u91cd\u7d99\u627f\u3092\u5b9f\u73fe\u3059\u308b\u65b9\u6cd5<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>\u5b9f\u8df5\u7684\u306a\u8a2d\u8a08\u30d1\u30bf\u30fc\u30f3<\/strong>\u2014\u2014\u73fe\u5834\u3067\u4f7f\u3048\u308binterface\u6d3b\u7528\u6cd5<\/li><\/ul>\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-01\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">01<\/span>\n  <span class=\"section-label\" style=\"display:block;\">WHAT IS INTERFACE<\/span>\n  <span class=\"section-title\" style=\"display:block;\">Java\u306einterface\u3068\u306f\u4f55\u304b<\/span>\n  <span class=\"section-desc\">\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u8a2d\u8a08\u306b\u304a\u3051\u308b\u300c\u7d04\u675f\u4e8b\u300d\u306e\u4ed5\u7d44\u307f\u3092\u7406\u89e3\u3059\u308b<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">interface\u3068\u306f\u3001\u3072\u3068\u3053\u3068\u3067\u8a00\u3048\u3070<strong>\u300c\u3053\u306e\u30af\u30e9\u30b9\u306f\u3053\u308c\u304c\u3067\u304d\u307e\u3059\u3088\u300d\u3068\u3044\u3046\u7d04\u675f\u4e8b\uff08\u5951\u7d04\uff09\u3092\u5b9a\u7fa9\u3059\u308b\u305f\u3081\u306e\u4ed5\u7d44\u307f<\/strong>\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u305f\u3068\u3048\u3070\u3001\u300c\u98db\u3079\u308b\u300d\u3068\u3044\u3046interface\u3092\u5b9a\u7fa9\u3059\u308c\u3070\u3001\u9ce5\u30fb\u30c9\u30ed\u30fc\u30f3\u30fb\u98db\u884c\u6a5f\u306a\u3069\u306e\u7570\u306a\u308b\u30af\u30e9\u30b9\u304c\u3001\u305d\u308c\u305e\u308c\u7570\u306a\u308b\u65b9\u6cd5\u3067\u300c\u98db\u3076\u300d\u3092\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002\u547c\u3073\u51fa\u3057\u5074\u306f\u300c\u98db\u3079\u308b\u3082\u306e\u300d\u3068\u3057\u3066\u6271\u3048\u308c\u3070\u3088\u304f\u3001\u5b9f\u969b\u306b\u3069\u3093\u306a\u7269\u4f53\u304c\u98db\u3093\u3067\u3044\u308b\u304b\u306f\u77e5\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u305b\u3093\u3002\u3053\u308c\u304c<strong>\u30dd\u30ea\u30e2\u30fc\u30d5\u30a3\u30ba\u30e0\uff08\u591a\u614b\u6027\uff09<\/strong>\u306e\u672c\u8cea\u3067\u3059\u3002<\/p>\n\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: \u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\uff08interface\uff09<\/p><p style=\"margin:0;color:#555\">Java\u306b\u304a\u3051\u308binterface\u3068\u306f\u3001\u30af\u30e9\u30b9\u304c\u5b9f\u88c5\u3059\u3079\u304d\u30e1\u30bd\u30c3\u30c9\u306e\u540d\u524d\u30fb\u5f15\u6570\u30fb\u623b\u308a\u5024\u578b\u3060\u3051\u3092\u5b9a\u7fa9\u3057\u305f\u300c\u8a2d\u8a08\u56f3\u306e\u8a2d\u8a08\u56f3\u300d\u3067\u3059\u3002interface\u305d\u306e\u3082\u306e\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3067\u304d\u307e\u305b\u3093\u3002interface\u3092\u5b9f\u88c5\u3057\u305f\u30af\u30e9\u30b9\u304c\u3001\u5b9f\u969b\u306e\u51e6\u7406\u3092\u8a18\u8ff0\u3057\u307e\u3059\u3002Java 8\u4ee5\u964d\u306fdefault\u30e1\u30bd\u30c3\u30c9\u3068static\u30e1\u30bd\u30c3\u30c9\u3082\u6301\u3066\u307e\u3059\u3002<\/p><\/div>\n\n\n<h3 class=\"wp-block-heading\">1-1. interface\u304c\u5fc5\u8981\u306a\u7406\u7531<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u300c\u30e1\u30bd\u30c3\u30c9\u306e\u4e2d\u8eab\u3092\u66f8\u304b\u306a\u3044\u306a\u3089\u3001\u306a\u305cinterface\u304c\u5fc5\u8981\u306a\u306e\u304b\uff1f\u300d\u3068\u3044\u3046\u7591\u554f\u306f\u3088\u304f\u3042\u308a\u307e\u3059\u3002\u305d\u306e\u7b54\u3048\u306f<strong>\u300c\u547c\u3073\u51fa\u3057\u5074\u3068\u5b9f\u88c5\u5074\u306e\u4f9d\u5b58\u95a2\u4fc2\u3092\u5207\u308a\u96e2\u3059\u305f\u3081\u300d<\/strong>\u3067\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">\u5177\u4f53\u4f8b\u3067\u8003\u3048\u307e\u3057\u3087\u3046\u3002\u793e\u5185\u30b7\u30b9\u30c6\u30e0\u306b\u300c\u901a\u77e5\u6a5f\u80fd\u300d\u304c\u3042\u308b\u3068\u3057\u307e\u3059\u3002\u73fe\u5728\u306f\u30e1\u30fc\u30eb\u901a\u77e5\u3067\u3059\u304c\u3001\u5c06\u6765\u7684\u306b\u306fSlack\u901a\u77e5\u3084SMS\u901a\u77e5\u306b\u5207\u308a\u66ff\u3048\u308b\u304b\u3082\u3057\u308c\u306a\u3044\u3002\u3053\u306e\u3068\u304d\u3001\u901a\u77e5\u65b9\u6cd5\u3054\u3068\u306b\u30e1\u30a4\u30f3\u306e\u51e6\u7406\u30b3\u30fc\u30c9\u3092\u66f8\u304d\u63db\u3048\u308b\u306e\u306f\u5371\u967a\u3067\u3059\u3002\u30d0\u30b0\u304c\u751f\u307e\u308c\u3084\u3059\u304f\u3001\u30c6\u30b9\u30c8\u3082\u5927\u5909\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<p class=\"wp-block-paragraph\">interface\u3092\u4f7f\u3048\u3070\u3001\u300c\u901a\u77e5\u3059\u308b\u300d\u3068\u3044\u3046<strong>\u5951\u7d04\u3060\u3051\u3092\u56fa\u5b9a<\/strong>\u3057\u3066\u3001\u5b9f\u88c5\u306f\u30e1\u30fc\u30eb\u30fbSlack\u30fbSMS\u3067\u81ea\u7531\u306b\u5909\u3048\u3089\u308c\u307e\u3059\u3002\u30e1\u30a4\u30f3\u306e\u51e6\u7406\u30b3\u30fc\u30c9\u306finterface\u578b\u3067\u53d7\u3051\u53d6\u308b\u3060\u3051\u306a\u306e\u3067\u3001\u901a\u77e5\u65b9\u6cd5\u304c\u5909\u308f\u3063\u3066\u3082\u4e00\u5207\u4fee\u6b63\u4e0d\u8981\u3067\u3059\u3002<\/p>\n\n\n<div class=\"g-flow-row\" style=\"display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin:20px 0;padding:16px;background:#ecf0f1;border-radius:6px\"><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">interface\u5b9a\u7fa9<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">\u5b9f\u88c5\u30af\u30e9\u30b9\u4f5c\u6210<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">implements\u5ba3\u8a00<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">\u547c\u3073\u51fa\u3057\u5074\u306finterface\u578b\u3067\u4f7f\u3046<\/div><\/div>\n\n\n<div class=\"balloon-wrap is-right\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/yamazaki-avatar.png\" alt=\"AI\u9b3c\u7ba1\u7406\u5c71\u5d0e\">\n    <span class=\"balloon-name\">AI\u9b3c\u7ba1\u7406\u5c71\u5d0e<\/span>\n  <\/div>\n  <div class=\"balloon-body\">interface\u306e\u672c\u8cea\u306f\u300c\u4f55\u304c\u3067\u304d\u308b\u304b\uff08What\uff09\u3092\u5b9a\u7fa9\u3057\u3001\u3069\u3046\u3084\u308b\u304b\uff08How\uff09\u306f\u5b9f\u88c5\u30af\u30e9\u30b9\u306b\u4efb\u305b\u308b\u300d\u3068\u3044\u3046\u5206\u696d\u306e\u4ed5\u7d44\u307f\u3067\u3059\u3002\u3053\u306e\u8003\u3048\u65b9\u3092\u300c\u4f9d\u5b58\u6027\u306e\u9006\u8ee2\u539f\u5247\uff08DIP\uff09\u300d\u3068\u547c\u3073\u307e\u3059\u3002\u521d\u5fc3\u8005\u306e\u3046\u3061\u306f\u300c\u578b\u3068\u3057\u3066\u4f7f\u3048\u308b\u7d04\u675f\u66f8\u300d\u3068\u3044\u3046\u30a4\u30e1\u30fc\u30b8\u3067\u5341\u5206\u3067\u3059\u3002<\/div>\n<\/div>\n\n\n\n<h3 class=\"wp-block-heading\">1-2. interface\u3068\u30af\u30e9\u30b9\u306e\u57fa\u672c\u7684\u306a\u9055\u3044<\/h3>\n\n\n\n<table>\n<thead><tr><th>\u9805\u76ee<\/th><th>interface<\/th><th>\u901a\u5e38\u306e\u30af\u30e9\u30b9<\/th><\/tr><\/thead>\n<tbody>\n<tr><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u751f\u6210<\/td><td>\u4e0d\u53ef<\/td><td>\u53ef<\/td><\/tr>\n<tr><td>\u30e1\u30bd\u30c3\u30c9\u306e\u4e2d\u8eab<\/td><td>\u539f\u5247\u306a\u3057\uff08Java 8\u4ee5\u964d\u306fdefault\u3067\u6301\u3066\u308b\uff09<\/td><td>\u3042\u308a<\/td><\/tr>\n<tr><td>\u30d5\u30a3\u30fc\u30eb\u30c9<\/td><td>public static final\u5b9a\u6570\u306e\u307f<\/td><td>\u81ea\u7531<\/td><\/tr>\n<tr><td>\u7d99\u627f<\/td><td>\u8907\u6570\u306einterface\u3092implements\u53ef\u80fd<\/td><td>1\u30af\u30e9\u30b9\u306e\u307fextends<\/td><\/tr>\n<tr><td>\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf<\/td><td>\u306a\u3057<\/td><td>\u3042\u308a<\/td><\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<p class=\"wp-block-paragraph\">\u6700\u5927\u306e\u9055\u3044\u306f<strong>\u300c\u8907\u6570\u306einterface\u3092\u540c\u6642\u306b\u5b9f\u88c5\u3067\u304d\u308b\u300d<\/strong>\u3068\u3044\u3046\u70b9\u3067\u3059\u3002\u901a\u5e38\u306e\u30af\u30e9\u30b9\u7d99\u627f\u3067\u306f\u89aa\u30af\u30e9\u30b9\u306f1\u3064\u3060\u3051\u3067\u3059\u304c\u3001interface\u306f\u4f55\u500b\u3067\u3082implements\u3067\u304d\u307e\u3059\u3002\u3053\u308c\u304cJava\u3067\u591a\u91cd\u7d99\u627f\u3092\u5b9f\u73fe\u3059\u308b\u552f\u4e00\u306e\u65b9\u6cd5\u3067\u3059\uff08\u8a73\u7d30\u306fH2\u300c\u8907\u6570interface\u306e\u5b9f\u88c5\u300d\u3067\u89e3\u8aac\uff09\u3002<\/p>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-02\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">02<\/span>\n  <span class=\"section-label\" style=\"display:block;\">SYNTAX & IMPLEMENTS<\/span>\n  <span class=\"section-title\" style=\"display:block;\">interface\u306e\u57fa\u672c\u7684\u306a\u66f8\u304d\u65b9\u3068\u5b9f\u88c5<\/span>\n  <span class=\"section-desc\">interface\u5b9a\u7fa9\u304b\u3089implements\u307e\u3067\u3001\u30b3\u30fc\u30c9\u3067\u5b8c\u5168\u7406\u89e3\u3059\u308b<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">interface\u306e\u69cb\u6587\u306f\u975e\u5e38\u306b\u30b7\u30f3\u30d7\u30eb\u3067\u3059\u3002<code>interface<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4f7f\u3063\u3066\u5b9a\u7fa9\u3057\u3001\u5b9f\u88c5\u30af\u30e9\u30b9\u3067\u306f<code>implements<\/code>\u30ad\u30fc\u30ef\u30fc\u30c9\u3067\u9069\u7528\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">2-1. interface\u306e\u5b9a\u7fa9<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u307e\u305a\u3001\u6700\u3082\u30b7\u30f3\u30d7\u30eb\u306ainterface\u306e\u5b9a\u7fa9\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u300c\u901a\u77e5\u3067\u304d\u308b\u300d\u3068\u3044\u3046\u5951\u7d04\u3092\u8868\u3059<code>Notifiable<\/code>\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u3092\u5b9a\u7fa9\u3057\u307e\u3059\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ Notifiable.java\npublic interface Notifiable {\n\n    \/\/ \u30e1\u30bd\u30c3\u30c9\u306e\u30b7\u30b0\u30cd\u30c1\u30e3\u306e\u307f\uff08\u5b9f\u88c5\u306f\u66f8\u304b\u306a\u3044\uff09\n    void send(String recipient, String message);\n\n    \/\/ \u8907\u6570\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u5b9a\u7fa9\u3067\u304d\u308b\n    boolean isAvailable();\n\n    \/\/ \u5b9a\u6570\u3092\u5b9a\u7fa9\u3067\u304d\u308b\uff08\u6697\u9ed9\u7684\u306bpublic static final\uff09\n    int MAX_MESSAGE_LENGTH = 1000;\n}<\/code><\/pre>\n\n\n<p class=\"wp-block-paragraph\">\u30dd\u30a4\u30f3\u30c8\u3092\u307e\u3068\u3081\u307e\u3059\uff1a<\/p>\n\n\n<ul style=\"list-style:none;padding:0;margin:16px 0\"><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>\u30e1\u30bd\u30c3\u30c9\u306e\u4e2d\u8eab\uff08\u51e6\u7406\uff09\u306f\u66f8\u304b\u306a\u3044<\/strong>\u2014\u2014\u30b7\u30b0\u30cd\u30c1\u30e3\uff08\u540d\u524d\u30fb\u5f15\u6570\u30fb\u623b\u308a\u5024\u578b\uff09\u3060\u3051<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>\u30a2\u30af\u30bb\u30b9\u4fee\u98fe\u5b50\u306f\u3059\u3079\u3066\u6697\u9ed9\u7684\u306bpublic<\/strong>\u2014\u2014\u7701\u7565\u3057\u3066\u3082public\u3068\u3057\u3066\u6271\u308f\u308c\u308b<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>\u30d5\u30a3\u30fc\u30eb\u30c9\u306fpublic static final\u5b9a\u6570\u306e\u307f<\/strong>\u2014\u2014\u5024\u3092\u5909\u3048\u3089\u308c\u306a\u3044\u30af\u30e9\u30b9\u5b9a\u6570<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>interface\u306e\u4e2d\u306e\u30e1\u30bd\u30c3\u30c9\u306fabstract\u3068\u540c\u3058<\/strong>\u2014\u2014\u5b9f\u88c5\u306f\u6301\u305f\u306a\u3044<\/li><\/ul>\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: implements<\/p><p style=\"margin:0;color:#555\">\u30af\u30e9\u30b9\u304cinterface\u3092\u5b9f\u88c5\u3059\u308b\u3053\u3068\u3092\u5ba3\u8a00\u3059\u308bJava\u306e\u30ad\u30fc\u30ef\u30fc\u30c9\u3002\u300c\u3053\u306e\u30af\u30e9\u30b9\u306finterface\u3067\u5b9a\u7fa9\u3055\u308c\u305f\u5168\u30e1\u30bd\u30c3\u30c9\u3092\u5b9f\u88c5\u3059\u308b\u300d\u3068\u3044\u3046\u7d04\u675f\u3092\u610f\u5473\u3057\u307e\u3059\u3002implements\u3092\u5ba3\u8a00\u3057\u305f\u30af\u30e9\u30b9\u304cinterface\u5185\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u5b9f\u88c5\u3057\u306a\u3044\u3068\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002\u8907\u6570\u306einterface\u3092\u5b9f\u88c5\u3059\u308b\u5834\u5408\u306f\u30ab\u30f3\u30de\u533a\u5207\u308a\u3067\u4e26\u3079\u307e\u3059\u3002<\/p><\/div>\n\n\n<h3 class=\"wp-block-heading\">2-2. implements\u306b\u3088\u308b\u5b9f\u88c5<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u5b9a\u7fa9\u3057\u305finterface\u3092\u5b9f\u969b\u306e\u30af\u30e9\u30b9\u3067\u5b9f\u88c5\u3057\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u30e1\u30fc\u30eb\u901a\u77e5\u30af\u30e9\u30b9\u3068Slack\u901a\u77e5\u30af\u30e9\u30b9\u306e2\u3064\u3092\u4f5c\u308a\u307e\u3059\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ EmailNotifier.java\npublic class EmailNotifier implements Notifiable {\n\n    private String smtpServer;\n\n    public EmailNotifier(String smtpServer) {\n        this.smtpServer = smtpServer;\n    }\n\n    \/\/ interface\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u5b9f\u88c5\uff08@Override\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u3092\u4ed8\u3051\u308b\u306e\u304c\u63a8\u5968\uff09\n    @Override\n    public void send(String recipient, String message) {\n        if (message.length() &gt; MAX_MESSAGE_LENGTH) {\n            throw new IllegalArgumentException(\"\u30e1\u30c3\u30bb\u30fc\u30b8\u304c\u9577\u3059\u304e\u307e\u3059\");\n        }\n        System.out.println(\"[Email] \" + recipient + \"\u3078\u9001\u4fe1: \" + message);\n        \/\/ \u5b9f\u969b\u306b\u306fsmtpServer\u3092\u4f7f\u3063\u3066\u30e1\u30fc\u30eb\u9001\u4fe1\u3059\u308b\u51e6\u7406\u3092\u66f8\u304f\n    }\n\n    @Override\n    public boolean isAvailable() {\n        \/\/ SMTP\u30b5\u30fc\u30d0\u30fc\u3078\u306e\u63a5\u7d9a\u78ba\u8a8d\u30ed\u30b8\u30c3\u30af\uff08\u3053\u3053\u3067\u306f\u7c21\u7565\u5316\uff09\n        return smtpServer != null &amp;&amp; !smtpServer.isEmpty();\n    }\n}<\/code><\/pre>\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ SlackNotifier.java\npublic class SlackNotifier implements Notifiable {\n\n    private String webhookUrl;\n\n    public SlackNotifier(String webhookUrl) {\n        this.webhookUrl = webhookUrl;\n    }\n\n    @Override\n    public void send(String recipient, String message) {\n        System.out.println(\"[Slack] \u30c1\u30e3\u30f3\u30cd\u30eb \" + recipient + \"\u3078\u6295\u7a3f: \" + message);\n        \/\/ \u5b9f\u969b\u306b\u306fWebhook URL\u3078HTTP\u30ea\u30af\u30a8\u30b9\u30c8\u3092\u9001\u308b\u51e6\u7406\u3092\u66f8\u304f\n    }\n\n    @Override\n    public boolean isAvailable() {\n        return webhookUrl != null &amp;&amp; !webhookUrl.isEmpty();\n    }\n}<\/code><\/pre>\n\n\n<p class=\"wp-block-paragraph\">\u6b21\u306b\u3001\u547c\u3073\u51fa\u3057\u5074\u306e\u30b3\u30fc\u30c9\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002\u3053\u3053\u304cinterface\u306e\u771f\u4fa1\u3092\u767a\u63ee\u3059\u308b\u5834\u9762\u3067\u3059\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ NotificationService.java\uff08\u547c\u3073\u51fa\u3057\u5074\uff09\npublic class NotificationService {\n\n    \/\/ interface\u578b\u3067\u53d7\u3051\u53d6\u308b\u2014\u2014EmailNotifier\u3067\u3082SlackNotifier\u3067\u3082\u4f7f\u3048\u308b\n    private Notifiable notifier;\n\n    public NotificationService(Notifiable notifier) {\n        this.notifier = notifier;\n    }\n\n    public void notifyUser(String userId, String message) {\n        if (notifier.isAvailable()) {\n            notifier.send(userId, message);\n        } else {\n            System.out.println(\"\u901a\u77e5\u30b5\u30fc\u30d3\u30b9\u304c\u5229\u7528\u4e0d\u53ef\u80fd\u3067\u3059\");\n        }\n    }\n}\n\n\/\/ Main.java\npublic class Main {\n    public static void main(String[] args) {\n\n        \/\/ \u30e1\u30fc\u30eb\u901a\u77e5\u3092\u4f7f\u3046\u5834\u5408\n        Notifiable emailNotifier = new EmailNotifier(\"smtp.example.com\");\n        NotificationService service1 = new NotificationService(emailNotifier);\n        service1.notifyUser(\"user@example.com\", \"\u3054\u6ce8\u6587\u3092\u627f\u308a\u307e\u3057\u305f\");\n\n        \/\/ Slack\u901a\u77e5\u306b\u5207\u308a\u66ff\u3048\u308b\u5834\u5408\u2014\u2014NotificationService\u306e\u30b3\u30fc\u30c9\u306f\u4e00\u5207\u5909\u66f4\u4e0d\u8981\n        Notifiable slackNotifier = new SlackNotifier(\"https:\/\/hooks.slack.com\/xxx\");\n        NotificationService service2 = new NotificationService(slackNotifier);\n        service2.notifyUser(\"#orders\", \"\u65b0\u898f\u6ce8\u6587\u304c\u5165\u308a\u307e\u3057\u305f\");\n    }\n}<\/code><\/pre>\n\n\n<div class=\"balloon-wrap\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/ceo-sugasawa.jpg\" alt=\"\u4ee3\u8868\u83c5\u6fa4\">\n    <span class=\"balloon-name\">\u4ee3\u8868\u83c5\u6fa4<\/span>\n  <\/div>\n  <div class=\"balloon-body\">\u300cNotificationService\u306e\u30b3\u30fc\u30c9\u306f\u4e00\u5207\u5909\u66f4\u4e0d\u8981\u300d\u2014\u2014\u3053\u3053\u304c\u5927\u4e8b\u3067\u3059\u3002\u30e1\u30fc\u30eb\u901a\u77e5\u304b\u3089Slack\u901a\u77e5\u306b\u5207\u308a\u66ff\u3048\u305f\u3068\u304d\u3001NotificationService\u3092\u4fee\u6b63\u3057\u306a\u304f\u3066\u3044\u3044\u3002interface\u3092\u4f7f\u3046\u3068\u3001\u5909\u66f4\u306e\u5f71\u97ff\u7bc4\u56f2\u304c\u6700\u5c0f\u5316\u3055\u308c\u307e\u3059\u3002\u3053\u308c\u304c\u300c\u758e\u7d50\u5408\u300d\u306a\u8a2d\u8a08\u3067\u3059\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-03\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">03<\/span>\n  <span class=\"section-label\" style=\"display:block;\">INTERFACE vs ABSTRACT<\/span>\n  <span class=\"section-title\" style=\"display:block;\">\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3092\u5fb9\u5e95\u6bd4\u8f03<\/span>\n  <span class=\"section-desc\">\u300c\u3069\u3061\u3089\u3092\u4f7f\u3046\u3079\u304d\u304b\u300d\u306e\u5224\u65ad\u57fa\u6e96\u3092\u5b8c\u5168\u6574\u7406<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Java\u3092\u5b66\u3076\u3068\u5fc5\u305a\u60a9\u3080\u306e\u304c\u300cinterface\u3068\u62bd\u8c61\u30af\u30e9\u30b9\u3001\u3069\u3061\u3089\u3092\u4f7f\u3048\u3070\u3044\u3044\u306e\uff1f\u300d\u3068\u3044\u3046\u554f\u3044\u3067\u3059\u3002\u7d50\u8ad6\u304b\u3089\u8a00\u3048\u3070<strong>\u300cis-a\u95a2\u4fc2\u306a\u3089abstract class\u3001can-do\u95a2\u4fc2\u306a\u3089interface\u300d<\/strong>\u304c\u57fa\u672c\u7684\u306a\u4f7f\u3044\u5206\u3051\u3067\u3059\u3002<\/p>\n\n\n<div class=\"g-flow-row\" style=\"display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin:20px 0;padding:16px;background:#ecf0f1;border-radius:6px\"><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">\u8a2d\u8a08\u306e\u5224\u65ad<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">is-a\u95a2\u4fc2\uff1f\uff08\u7d99\u627f\uff09<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">\u2192 abstract class<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">can-do\u95a2\u4fc2\uff1f\uff08\u80fd\u529b\uff09<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">\u2192 interface<\/div><\/div>\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: abstract class\uff08\u62bd\u8c61\u30af\u30e9\u30b9\uff09<\/p><p style=\"margin:0;color:#555\">abstract\u30ad\u30fc\u30ef\u30fc\u30c9\u3067\u5ba3\u8a00\u3055\u308c\u305f\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u751f\u6210\u3067\u304d\u306a\u3044\u30af\u30e9\u30b9\u306e\u3053\u3068\u3002\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\uff08\u51e6\u7406\u306a\u3057\uff09\u3068\u901a\u5e38\u30e1\u30bd\u30c3\u30c9\uff08\u51e6\u7406\u3042\u308a\uff09\u306e\u4e21\u65b9\u3092\u6301\u3066\u307e\u3059\u3002\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3082\u6301\u3066\u308b\u305f\u3081\u3001\u5171\u901a\u306e\u521d\u671f\u5316\u51e6\u7406\u3092\u6301\u305f\u305b\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002\u30b5\u30d6\u30af\u30e9\u30b9\u306fextends\u3067\u7d99\u627f\u3057\u3001\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u5b9f\u88c5\u3057\u307e\u3059\u30021\u30af\u30e9\u30b9\u3057\u304b\u7d99\u627f\u3067\u304d\u306a\u3044\u70b9\u304cinterface\u3068\u306e\u5927\u304d\u306a\u9055\u3044\u3067\u3059\u3002<\/p><\/div>\n\n\n<h3 class=\"wp-block-heading\">3-1. \u8a73\u7d30\u6bd4\u8f03\u8868<\/h3>\n\n\n\n<table>\n<thead><tr><th>\u6bd4\u8f03\u9805\u76ee<\/th><th>interface<\/th><th>abstract class<\/th><\/tr><\/thead>\n<tbody>\n<tr><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u751f\u6210<\/td><td>\u4e0d\u53ef<\/td><td>\u4e0d\u53ef<\/td><\/tr>\n<tr><td>\u901a\u5e38\u30e1\u30bd\u30c3\u30c9\u306e\u5b9f\u88c5<\/td><td>\u4e0d\u53ef\uff08default\u30e1\u30bd\u30c3\u30c9\u306f\u4f8b\u5916\uff09<\/td><td>\u53ef<\/td><\/tr>\n<tr><td>\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9<\/td><td>\u5168\u30e1\u30bd\u30c3\u30c9\u304c\u62bd\u8c61\uff08default\u3092\u9664\u304f\uff09<\/td><td>\u4e00\u90e8\u307e\u305f\u306f\u5168\u90e8\u304c\u62bd\u8c61<\/td><\/tr>\n<tr><td>\u30d5\u30a3\u30fc\u30eb\u30c9<\/td><td>public static final\u5b9a\u6570\u306e\u307f<\/td><td>\u81ea\u7531\uff08private\/protected\u7b49\u3082\u53ef\uff09<\/td><\/tr>\n<tr><td>\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf<\/td><td>\u306a\u3057<\/td><td>\u3042\u308a<\/td><\/tr>\n<tr><td>\u591a\u91cd\u5b9f\u88c5\/\u7d99\u627f<\/td><td>\u8907\u6570implements\u3067\u591a\u91cd\u5b9f\u88c5OK<\/td><td>extends\u306f1\u30af\u30e9\u30b9\u306e\u307f<\/td><\/tr>\n<tr><td>\u30a2\u30af\u30bb\u30b9\u4fee\u98fe\u5b50<\/td><td>\u6697\u9ed9\u7684\u306bpublic<\/td><td>\u81ea\u7531\u306b\u8a2d\u5b9a\u53ef<\/td><\/tr>\n<tr><td>\u4e3b\u306a\u7528\u9014<\/td><td>\u80fd\u529b\u30fb\u5951\u7d04\u306e\u5b9a\u7fa9<\/td><td>\u5171\u901a\u306e\u57fa\u76e4\u30af\u30e9\u30b9\u306e\u5b9a\u7fa9<\/td><\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<h3 class=\"wp-block-heading\">3-2. \u30b3\u30fc\u30c9\u3067\u6bd4\u8f03\u3059\u308b<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">\u300c\u52d5\u7269\u300d\u3092\u4f8b\u306b\u3001interface\u3068\u62bd\u8c61\u30af\u30e9\u30b9\u306e\u4f7f\u3044\u5206\u3051\u3092\u898b\u3066\u307f\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ \u62bd\u8c61\u30af\u30e9\u30b9: \u52d5\u7269\u3068\u3044\u3046\u300c\u7a2e\u985e\u300d\u306e\u5171\u901a\u57fa\u76e4\n\/\/ \u300c\u52d5\u7269\u3067\u3042\u308b\uff08is-a\uff09\u300d\u3068\u3044\u3046\u7d99\u627f\u95a2\u4fc2\npublic abstract class Animal {\n\n    protected String name;\n    protected int age;\n\n    \/\/ \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\uff08\u62bd\u8c61\u30af\u30e9\u30b9\u306f\u6301\u3066\u308b\uff09\n    public Animal(String name, int age) {\n        this.name = name;\n        this.age = age;\n    }\n\n    \/\/ \u901a\u5e38\u30e1\u30bd\u30c3\u30c9\uff08\u5171\u901a\u5b9f\u88c5\uff09\n    public void breathe() {\n        System.out.println(name + \"\u306f\u547c\u5438\u3057\u3066\u3044\u308b\");\n    }\n\n    \/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\uff08\u5404\u30b5\u30d6\u30af\u30e9\u30b9\u3067\u5b9f\u88c5\u5fc5\u9808\uff09\n    public abstract void makeSound();\n\n    public String getName() { return name; }\n    public int getAge() { return age; }\n}\n\n\/\/ interface: \u300c\u98db\u3079\u308b\u80fd\u529b\uff08can-do\uff09\u300d\u306e\u5951\u7d04\n\/\/ \u72ac\u3082\u98db\u884c\u6a5f\u3082\u540c\u3058interface\u3092\u5b9f\u88c5\u3067\u304d\u308b\npublic interface Flyable {\n    void fly();\n    int getMaxAltitude();\n}\n\n\/\/ interface: \u300c\u6cf3\u3052\u308b\u80fd\u529b\uff08can-do\uff09\u300d\u306e\u5951\u7d04\npublic interface Swimmable {\n    void swim();\n    double getMaxSpeed();\n}\n\n\/\/ Dog\u30af\u30e9\u30b9: Animal\u3092\u7d99\u627f\uff08is-a\uff09\npublic class Dog extends Animal {\n    public Dog(String name, int age) {\n        super(name, age);\n    }\n\n    @Override\n    public void makeSound() {\n        System.out.println(name + \"\uff1a\u30ef\u30f3\u30ef\u30f3\uff01\");\n    }\n}\n\n\/\/ Duck\u30af\u30e9\u30b9: Animal\u3092\u7d99\u627f\u3057\u3064\u3064\u3001\u98db\u3079\u3066\u6cf3\u3052\u308binterface\u3082\u5b9f\u88c5\n\/\/ \u2192 interface\u306e\u304a\u304b\u3052\u3067\u591a\u91cd\u300c\u80fd\u529b\u300d\u3092\u6301\u3066\u308b\npublic class Duck extends Animal implements Flyable, Swimmable {\n\n    public Duck(String name, int age) {\n        super(name, age);\n    }\n\n    @Override\n    public void makeSound() {\n        System.out.println(name + \"\uff1a\u30ac\u30fc\u30ac\u30fc\uff01\");\n    }\n\n    @Override\n    public void fly() {\n        System.out.println(name + \"\u304c\u98db\u3093\u3067\u3044\u307e\u3059\");\n    }\n\n    @Override\n    public int getMaxAltitude() { return 500; }\n\n    @Override\n    public void swim() {\n        System.out.println(name + \"\u304c\u6cf3\u3044\u3067\u3044\u307e\u3059\");\n    }\n\n    @Override\n    public double getMaxSpeed() { return 3.5; }\n}<\/code><\/pre>\n\n<div style=\"border:2px solid #27ae60;border-radius:6px;padding:16px 20px;margin:24px 0;background:#f0fff4\"><p style=\"font-weight:bold;color:#27ae60;margin:0 0 8px\">\ud83d\udca1 \u4f7f\u3044\u5206\u3051\u306e\u5224\u65ad\u30d5\u30ed\u30fc<\/p><p style=\"margin:0\">\u2460 \u300cA\u306fB\u306e\u4e00\u7a2e\u3060\u300d\u3068\u8a00\u3048\u308b \u2192 abstract class\uff08\u4f8b\uff1a\u72ac\u306f\u52d5\u7269\u306e\u4e00\u7a2e\uff09\u3002\u2461 \u300cA\u306fB\u304c\u3067\u304d\u308b\u300d\u3068\u8a00\u3048\u308b \u2192 interface\uff08\u4f8b\uff1a\u30a2\u30d2\u30eb\u306f\u98db\u3079\u308b\u3001\u6cf3\u3052\u308b\uff09\u3002\u2462 \u5171\u901a\u306e\u521d\u671f\u5316\u51e6\u7406\u3084\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u5fc5\u8981 \u2192 abstract class\u3002\u2463 \u8907\u6570\u306e\u7570\u306a\u308b\u30af\u30e9\u30b9\u306b\u540c\u3058\u80fd\u529b\u3092\u6301\u305f\u305b\u305f\u3044 \u2192 interface\u3002\u8ff7\u3063\u305f\u3089interface\u3092\u9078\u3076\u306e\u304c\u73fe\u4ee3Java\u306e\u4e3b\u6d41\u3067\u3059\u3002<\/p><\/div>\n\n\n<div class=\"balloon-wrap is-right\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/yamazaki-avatar.png\" alt=\"AI\u9b3c\u7ba1\u7406\u5c71\u5d0e\">\n    <span class=\"balloon-name\">AI\u9b3c\u7ba1\u7406\u5c71\u5d0e<\/span>\n  <\/div>\n  <div class=\"balloon-body\">Java 8\u4ee5\u964d\u306edefault\u30e1\u30bd\u30c3\u30c9\u306e\u767b\u5834\u3067\u300cinterface\u3067\u3082\u5171\u901a\u51e6\u7406\u304c\u66f8\u3051\u308b\u300d\u3088\u3046\u306b\u306a\u3063\u305f\u305f\u3081\u3001\u62bd\u8c61\u30af\u30e9\u30b9\u3092\u4f7f\u3046\u5834\u9762\u306f\u304b\u306a\u308a\u6e1b\u308a\u307e\u3057\u305f\u3002\u300c\u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3068protected\u30d5\u30a3\u30fc\u30eb\u30c9\u304c\u5fc5\u8981\u306a\u5834\u5408\u3060\u3051abstract class\u3092\u4f7f\u3046\u300d\u3068\u899a\u3048\u3066\u304a\u304f\u3068\u8ff7\u3044\u304c\u6e1b\u308a\u307e\u3059\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-04\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">04<\/span>\n  <span class=\"section-label\" style=\"display:block;\">DEFAULT METHOD<\/span>\n  <span class=\"section-title\" style=\"display:block;\">default\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u65b9\uff08Java 8\u4ee5\u964d\uff09<\/span>\n  <span class=\"section-desc\">interface\u306b\u5b9f\u88c5\u3092\u6301\u305f\u305b\u308b\u9769\u547d\u7684\u306a\u65b0\u6a5f\u80fd<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Java 8\uff082014\u5e74\u30ea\u30ea\u30fc\u30b9\uff09\u304b\u3089\u3001interface\u306b<strong>default\u30e1\u30bd\u30c3\u30c9<\/strong>\u3068\u3044\u3046\u9769\u547d\u7684\u306a\u6a5f\u80fd\u304c\u8ffd\u52a0\u3055\u308c\u307e\u3057\u305f\u3002default\u30e1\u30bd\u30c3\u30c9\u3092\u4f7f\u3046\u3068\u3001interface\u306b\u300c\u30c7\u30d5\u30a9\u30eb\u30c8\u306e\u51e6\u7406\u300d\u3092\u6301\u305f\u305b\u308b\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: default\u30e1\u30bd\u30c3\u30c9<\/p><p style=\"margin:0;color:#555\">Java 8\u4ee5\u964d\u3067interface\u306b\u8ffd\u52a0\u3055\u308c\u305f\u6a5f\u80fd\u3002default\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4ed8\u3051\u305f\u30e1\u30bd\u30c3\u30c9\u306b\u306f\u51e6\u7406\u3092\u8a18\u8ff0\u3067\u304d\u3001\u5b9f\u88c5\u30af\u30e9\u30b9\u3067\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u306a\u304f\u3066\u3082\u4f7f\u3048\u307e\u3059\u3002\u4e3b\u306a\u7528\u9014\u306f\u300c\u65e2\u5b58interface\u306b\u65b0\u3057\u3044\u30e1\u30bd\u30c3\u30c9\u3092\u8ffd\u52a0\u3057\u3066\u3082\u65e2\u5b58\u306e\u5b9f\u88c5\u30af\u30e9\u30b9\u304c\u58ca\u308c\u306a\u3044\u3088\u3046\u306b\u3059\u308b\u5f8c\u65b9\u4e92\u63db\u6027\u306e\u78ba\u4fdd\u300d\u3067\u3059\u3002<\/p><\/div>\n\n\n<h3 class=\"wp-block-heading\">4-1. default\u30e1\u30bd\u30c3\u30c9\u306e\u57fa\u672c\u69cb\u6587<\/h3>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ Printable.java\npublic interface Printable {\n\n    \/\/ \u901a\u5e38\u306e\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\uff08\u5b9f\u88c5\u5fc5\u9808\uff09\n    String getContent();\n\n    \/\/ default\u30e1\u30bd\u30c3\u30c9\uff08\u5b9f\u88c5\u30af\u30e9\u30b9\u3067\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u4e0d\u8981\uff09\n    default void print() {\n        System.out.println(\"=== \u5370\u5237\u958b\u59cb ===\");\n        System.out.println(getContent());\n        System.out.println(\"=== \u5370\u5237\u7d42\u4e86 ===\");\n    }\n\n    \/\/ default\u30e1\u30bd\u30c3\u30c9\u306f\u4ed6\u306edefault\u30e1\u30bd\u30c3\u30c9\u3092\u547c\u3079\u308b\n    default void printWithLineNumber() {\n        System.out.println(\"=== \u884c\u756a\u53f7\u4ed8\u304d\u5370\u5237 ===\");\n        String[] lines = getContent().split(\"\\n\");\n        for (int i = 0; i &lt; lines.length; i++) {\n            System.out.println((i + 1) + \": \" + lines[i]);\n        }\n    }\n}\n\n\/\/ SimpleDocument.java\npublic class SimpleDocument implements Printable {\n\n    private String text;\n\n    public SimpleDocument(String text) {\n        this.text = text;\n    }\n\n    \/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u306f\u5b9f\u88c5\u5fc5\u9808\n    @Override\n    public String getContent() {\n        return text;\n    }\n\n    \/\/ default\u30e1\u30bd\u30c3\u30c9\u306f\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u306a\u304f\u3066\u3082OK\n    \/\/ \uff08\u5fc5\u8981\u306a\u3089\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u4e0a\u66f8\u304d\u3067\u304d\u308b\uff09\n}\n\n\/\/ HtmlDocument.java\uff08default\u30e1\u30bd\u30c3\u30c9\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3059\u308b\u4f8b\uff09\npublic class HtmlDocument implements Printable {\n\n    private String html;\n\n    public HtmlDocument(String html) {\n        this.html = html;\n    }\n\n    @Override\n    public String getContent() {\n        return html;\n    }\n\n    \/\/ default\u30e1\u30bd\u30c3\u30c9\u3092\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3066\u72ec\u81ea\u306e\u6319\u52d5\u306b\u5909\u66f4\n    @Override\n    public void print() {\n        System.out.println(\"=== HTML\u5370\u5237\uff08\u30d6\u30e9\u30a6\u30b6\u30ec\u30f3\u30c0\u30ea\u30f3\u30b0\uff09 ===\");\n        \/\/ HTML\u30bf\u30b0\u3092\u9664\u53bb\u3057\u3066\u8868\u793a\n        System.out.println(html.replaceAll(\"&lt;[^&gt;]+&gt;\", \"\"));\n    }\n}\n\n\/\/ Main.java\npublic class Main {\n    public static void main(String[] args) {\n\n        SimpleDocument doc = new SimpleDocument(\"Hello\\nWorld\\nJava\");\n        doc.print();            \/\/ default\u30e1\u30bd\u30c3\u30c9\u304c\u305d\u306e\u307e\u307e\u52d5\u304f\n        doc.printWithLineNumber(); \/\/ \u3053\u3061\u3089\u3082default\u30e1\u30bd\u30c3\u30c9\n\n        HtmlDocument htmlDoc = new HtmlDocument(\"&lt;h1&gt;\u30bf\u30a4\u30c8\u30eb&lt;\/h1&gt;&lt;p&gt;\u672c\u6587&lt;\/p&gt;\");\n        htmlDoc.print();        \/\/ \u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u305f\u72ec\u81ea\u51e6\u7406\u304c\u52d5\u304f\n    }\n}<\/code><\/pre>\n\n\n<h3 class=\"wp-block-heading\">4-2. default\u30e1\u30bd\u30c3\u30c9\u304c\u89e3\u6c7a\u3059\u308b\u554f\u984c<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">default\u30e1\u30bd\u30c3\u30c9\u304c\u8ffd\u52a0\u3055\u308c\u305f\u6700\u5927\u306e\u7406\u7531\u306f<strong>\u300c\u5f8c\u65b9\u4e92\u63db\u6027\u306e\u78ba\u4fdd\u300d<\/strong>\u3067\u3059\u3002\u65e2\u5b58\u306einterface\u306b\u65b0\u3057\u3044\u30e1\u30bd\u30c3\u30c9\u3092\u8ffd\u52a0\u3059\u308b\u3068\u3001\u305d\u306einterface\u3092\u5b9f\u88c5\u3057\u3066\u3044\u308b\u5168\u30af\u30e9\u30b9\u3067\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u304c\u767a\u751f\u3057\u307e\u3059\u3002\u5927\u898f\u6a21\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306f\u81f4\u547d\u7684\u306a\u554f\u984c\u3067\u3059\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ \u554f\u984c\u306e\u3042\u308b\u30b1\u30fc\u30b9: \u65e2\u5b58interface\u306b\u30e1\u30bd\u30c3\u30c9\u3092\u8ffd\u52a0\u3057\u305f\u3089\u5168\u5b9f\u88c5\u30af\u30e9\u30b9\u304c\u30a8\u30e9\u30fc\npublic interface OldService {\n    void execute();\n    \/\/ void newMethod(); \/\/ \u2190 \u3053\u308c\u3092\u8ffd\u52a0\u3059\u308b\u3068\u65e2\u5b58\u306e\u5b9f\u88c5\u30af\u30e9\u30b9\u304c\u5168\u90e8\u58ca\u308c\u308b\uff01\n}\n\n\/\/ default\u30e1\u30bd\u30c3\u30c9\u3067\u89e3\u6c7a: \u65e2\u5b58\u30af\u30e9\u30b9\u3092\u58ca\u3055\u305a\u306b\u6a5f\u80fd\u8ffd\u52a0\u3067\u304d\u308b\npublic interface NewService {\n    void execute();\n\n    \/\/ default\u3067\u8ffd\u52a0\u3059\u308c\u3070\u65e2\u5b58\u5b9f\u88c5\u30af\u30e9\u30b9\u306f\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u3089\u306a\u3044\n    default void newMethod() {\n        System.out.println(\"\u30c7\u30d5\u30a9\u30eb\u30c8\u306e\u65b0\u6a5f\u80fd\");\n    }\n\n    default String getVersion() {\n        return \"2.0\";\n    }\n}<\/code><\/pre>\n\n\n<div class=\"balloon-wrap\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/ceo-sugasawa.jpg\" alt=\"\u4ee3\u8868\u83c5\u6fa4\">\n    <span class=\"balloon-name\">\u4ee3\u8868\u83c5\u6fa4<\/span>\n  <\/div>\n  <div class=\"balloon-body\">Java\u306e\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u304cJava 8\u3067Stream API\u3092\u30b5\u30dd\u30fc\u30c8\u3067\u304d\u305f\u306e\u3082\u3001default\u30e1\u30bd\u30c3\u30c9\u306e\u304a\u304b\u3052\u3067\u3059\u3002List\u3084Iterable\u306a\u3069\u306e\u65e2\u5b58interface\u306bforEach()\u306a\u3069\u306edefault\u30e1\u30bd\u30c3\u30c9\u3092\u8ffd\u52a0\u3057\u305f\u3053\u3068\u3067\u3001\u65e2\u5b58\u306e\u4f55\u5343\u3082\u306e\u30b5\u30fc\u30c9\u30d1\u30fc\u30c6\u30a3\u30e9\u30a4\u30d6\u30e9\u30ea\u3092\u58ca\u3055\u305a\u306b\u6a5f\u80fd\u62e1\u5f35\u3067\u304d\u307e\u3057\u305f\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-05\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">05<\/span>\n  <span class=\"section-label\" style=\"display:block;\">STATIC METHOD<\/span>\n  <span class=\"section-title\" style=\"display:block;\">static\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u65b9<\/span>\n  <span class=\"section-desc\">interface\u306b\u30e6\u30fc\u30c6\u30a3\u30ea\u30c6\u30a3\u6a5f\u80fd\u3092\u6301\u305f\u305b\u308b<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Java 8\u4ee5\u964d\u3001interface\u306b\u306f<strong>static\u30e1\u30bd\u30c3\u30c9<\/strong>\u3082\u5b9a\u7fa9\u3067\u304d\u307e\u3059\u3002static\u30e1\u30bd\u30c3\u30c9\u306f\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u4f5c\u3089\u305a\u306binterface\u540d\u3067\u76f4\u63a5\u547c\u3073\u51fa\u305b\u308b\u4fbf\u5229\u306a\u6a5f\u80fd\u3067\u3059\u3002<\/p>\n\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: static\u30e1\u30bd\u30c3\u30c9<\/p><p style=\"margin:0;color:#555\">static\u30ad\u30fc\u30ef\u30fc\u30c9\u3092\u4ed8\u3051\u305f\u30e1\u30bd\u30c3\u30c9\u306f\u3001\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u751f\u6210\u306a\u3057\u306b\u30af\u30e9\u30b9\u540d\uff08\u307e\u305f\u306finterface\u540d\uff09\u3067\u76f4\u63a5\u547c\u3073\u51fa\u305b\u307e\u3059\u3002interface\u306estatic\u30e1\u30bd\u30c3\u30c9\u306f\u5b9f\u88c5\u30af\u30e9\u30b9\u306b\u7d99\u627f\u3055\u308c\u306a\u3044\u70b9\u304c\u901a\u5e38\u306e\u30af\u30e9\u30b9\u306estatic\u30e1\u30bd\u30c3\u30c9\u3068\u7570\u306a\u308a\u307e\u3059\u3002interface\u540d\u3067\u660e\u793a\u7684\u306b\u547c\u3073\u51fa\u3059\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p><\/div>\n\n\n<h3 class=\"wp-block-heading\">5-1. interface\u306estatic\u30e1\u30bd\u30c3\u30c9\u306e\u57fa\u672c<\/h3>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ Validator.java\npublic interface Validator&lt;T&gt; {\n\n    \/\/ \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\uff08\u5b9f\u88c5\u5fc5\u9808\uff09\n    boolean validate(T value);\n\n    \/\/ static\u30e1\u30bd\u30c3\u30c9\uff08\u30d5\u30a1\u30af\u30c8\u30ea\u30e1\u30bd\u30c3\u30c9\u3068\u3057\u3066\u4f7f\u3046\u30d1\u30bf\u30fc\u30f3\uff09\n    static Validator&lt;String&gt; notEmpty() {\n        return value -&gt; value != null &amp;&amp; !value.trim().isEmpty();\n    }\n\n    static Validator&lt;Integer&gt; positive() {\n        return value -&gt; value != null &amp;&amp; value &gt; 0;\n    }\n\n    static Validator&lt;String&gt; maxLength(int max) {\n        return value -&gt; value != null &amp;&amp; value.length() &lt;= max;\n    }\n\n    \/\/ default\u30e1\u30bd\u30c3\u30c9\u3068\u306e\u7d44\u307f\u5408\u308f\u305b\uff08and\u3067\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\u3092\u9023\u7d50\uff09\n    default Validator&lt;T&gt; and(Validator&lt;T&gt; other) {\n        return value -&gt; this.validate(value) &amp;&amp; other.validate(value);\n    }\n}\n\n\/\/ Main.java\npublic class Main {\n    public static void main(String[] args) {\n\n        \/\/ static\u30e1\u30bd\u30c3\u30c9\u306finterface\u540d\u3067\u76f4\u63a5\u547c\u3073\u51fa\u3059\n        Validator&lt;String&gt; notEmpty = Validator.notEmpty();\n        Validator&lt;String&gt; maxLen20 = Validator.maxLength(20);\n\n        \/\/ default\u30e1\u30bd\u30c3\u30c9\u306eand\u3067\u9023\u7d50\n        Validator&lt;String&gt; nameValidator = Validator.notEmpty().and(Validator.maxLength(20));\n\n        System.out.println(nameValidator.validate(\"\u5c71\u5d0e\"));   \/\/ true\n        System.out.println(nameValidator.validate(\"\"));       \/\/ false\uff08\u7a7a\u6587\u5b57\uff09\n        System.out.println(nameValidator.validate(\"\u3042\u3044\u3046\u3048\u304a\u304b\u304d\u304f\u3051\u3053\u3055\u3057\u3059\u305b\u305d\u305f\u3061\u3064\u3066\u3068\u306a\u306b\u306c\u306d\u306e\")); \/\/ false\uff08\u9577\u3059\u304e\uff09\n\n        \/\/ \u6574\u6570\u30d0\u30ea\u30c7\u30fc\u30b7\u30e7\u30f3\n        Validator&lt;Integer&gt; priceValidator = Validator.positive();\n        System.out.println(priceValidator.validate(1000)); \/\/ true\n        System.out.println(priceValidator.validate(-1));   \/\/ false\n    }\n}<\/code><\/pre>\n\n\n<h3 class=\"wp-block-heading\">5-2. static\u30e1\u30bd\u30c3\u30c9\u3068default\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u5206\u3051<\/h3>\n\n\n\n<table>\n<thead><tr><th>\u9805\u76ee<\/th><th>default\u30e1\u30bd\u30c3\u30c9<\/th><th>static\u30e1\u30bd\u30c3\u30c9<\/th><\/tr><\/thead>\n<tbody>\n<tr><td>\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9<\/td><td>\u5b9f\u88c5\u30af\u30e9\u30b9\u3067\u53ef\u80fd<\/td><td>\u4e0d\u53ef<\/td><\/tr>\n<tr><td>\u7d99\u627f<\/td><td>\u30b5\u30d6\u30af\u30e9\u30b9\u306b\u7d99\u627f\u3055\u308c\u308b<\/td><td>\u3055\u308c\u306a\u3044<\/td><\/tr>\n<tr><td>\u547c\u3073\u51fa\u3057\u65b9<\/td><td>\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u304b\u3089\u547c\u3073\u51fa\u3059<\/td><td>interface\u540d\u3067\u76f4\u63a5\u547c\u3073\u51fa\u3059<\/td><\/tr>\n<tr><td>\u4e3b\u306a\u7528\u9014<\/td><td>\u30c7\u30d5\u30a9\u30eb\u30c8\u5b9f\u88c5\u30fb\u5f8c\u65b9\u4e92\u63db<\/td><td>\u30e6\u30fc\u30c6\u30a3\u30ea\u30c6\u30a3\u30fb\u30d5\u30a1\u30af\u30c8\u30ea\u30e1\u30bd\u30c3\u30c9<\/td><\/tr>\n<tr><td>this\u306e\u4f7f\u7528<\/td><td>\u53ef\uff08\u81ea\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u53c2\u7167\uff09<\/td><td>\u4e0d\u53ef<\/td><\/tr>\n<\/tbody>\n<\/table>\n\n\n\n<div class=\"balloon-wrap is-right\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/yamazaki-avatar.png\" alt=\"AI\u9b3c\u7ba1\u7406\u5c71\u5d0e\">\n    <span class=\"balloon-name\">AI\u9b3c\u7ba1\u7406\u5c71\u5d0e<\/span>\n  <\/div>\n  <div class=\"balloon-body\">static\u30e1\u30bd\u30c3\u30c9\u3092interface\u306b\u6301\u305f\u305b\u308b\u3053\u3068\u3067\u3001\u95a2\u9023\u3059\u308b\u300c\u30d5\u30a1\u30af\u30c8\u30ea\uff08\u751f\u6210\uff09\u30e1\u30bd\u30c3\u30c9\u300d\u3084\u300c\u30e6\u30fc\u30c6\u30a3\u30ea\u30c6\u30a3\uff08\u4fbf\u5229\u95a2\u6570\uff09\u300d\u3092interface\u81ea\u4f53\u306b\u96c6\u7d04\u3067\u304d\u307e\u3059\u3002\u5225\u306e\u30af\u30e9\u30b9\u3092\u4f5c\u308b\u5fc5\u8981\u304c\u306a\u304f\u306a\u308b\u306e\u3067\u3001\u30b3\u30fc\u30c9\u306e\u898b\u901a\u3057\u304c\u3088\u304f\u306a\u308a\u307e\u3059\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-06\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">06<\/span>\n  <span class=\"section-label\" style=\"display:block;\">MULTIPLE INTERFACES<\/span>\n  <span class=\"section-title\" style=\"display:block;\">\u8907\u6570interface\u306e\u5b9f\u88c5\uff08\u591a\u91cd\u7d99\u627f\uff09<\/span>\n  <span class=\"section-desc\">Java\u3067\u591a\u91cd\u7d99\u627f\u3092\u5b89\u5168\u306b\u5b9f\u73fe\u3059\u308b\u65b9\u6cd5<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Java\u306f\u30af\u30e9\u30b9\u306e\u591a\u91cd\u7d99\u627f\uff08\u8907\u6570\u306e\u89aa\u30af\u30e9\u30b9\u3092\u6301\u3064\uff09\u3092\u30b5\u30dd\u30fc\u30c8\u3057\u3066\u3044\u307e\u305b\u3093\u3002\u3053\u308c\u306f\u300c\u30c0\u30a4\u30a2\u30e2\u30f3\u30c9\u554f\u984c\u300d\u3068\u547c\u3070\u308c\u308b\u30d0\u30b0\u306e\u6e29\u5e8a\u306b\u306a\u308b\u305f\u3081\u3067\u3059\u3002\u3057\u304b\u3057\u3001<strong>interface\u306e\u8907\u6570\u5b9f\u88c5\uff08implements\uff09\u3092\u4f7f\u3048\u3070\u3001\u591a\u91cd\u7d99\u627f\u306b\u76f8\u5f53\u3059\u308b\u8a2d\u8a08\u304c\u3067\u304d\u307e\u3059<\/strong>\u3002<\/p>\n\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: \u591a\u91cd\u7d99\u627f<\/p><p style=\"margin:0;color:#555\">1\u3064\u306e\u30af\u30e9\u30b9\u304c\u8907\u6570\u306e\u89aa\u304b\u3089\u6027\u8cea\u3092\u53d7\u3051\u7d99\u3050\u3053\u3068\u3002C++\u306f\u591a\u91cd\u7d99\u627f\u3092\u30b5\u30dd\u30fc\u30c8\u3057\u307e\u3059\u304c\u3001\u540c\u540d\u30e1\u30bd\u30c3\u30c9\u304c\u3069\u306e\u89aa\u30af\u30e9\u30b9\u306e\u3082\u306e\u304b\u66d6\u6627\u306b\u306a\u308b\u300c\u30c0\u30a4\u30a2\u30e2\u30f3\u30c9\u554f\u984c\u300d\u304c\u767a\u751f\u3057\u307e\u3059\u3002Java\u306f\u30af\u30e9\u30b9\u306e\u591a\u91cd\u7d99\u627f\u3092\u7981\u6b62\u3057\u3001interface\u306e\u8907\u6570\u5b9f\u88c5\u306e\u307f\u3092\u8a31\u5bb9\u3059\u308b\u3053\u3068\u3067\u5b89\u5168\u6027\u3092\u78ba\u4fdd\u3057\u3066\u3044\u307e\u3059\u3002<\/p><\/div>\n\n\n<h3 class=\"wp-block-heading\">6-1. \u8907\u6570interface\u3092\u5b9f\u88c5\u3059\u308b\u57fa\u672c\u69cb\u6587<\/h3>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ Serializable.java\uff08\u30b7\u30ea\u30a2\u30e9\u30a4\u30ba\u53ef\u80fd\uff09\npublic interface Serializable {\n    String serialize();\n    Object deserialize(String data);\n}\n\n\/\/ Loggable.java\uff08\u30ed\u30b0\u8a18\u9332\u53ef\u80fd\uff09\npublic interface Loggable {\n    void log(String message);\n\n    default void logError(String message) {\n        log(\"[ERROR] \" + message);\n    }\n\n    default void logInfo(String message) {\n        log(\"[INFO] \" + message);\n    }\n}\n\n\/\/ Cacheable.java\uff08\u30ad\u30e3\u30c3\u30b7\u30e5\u53ef\u80fd\uff09\npublic interface Cacheable {\n    String getCacheKey();\n    int getCacheTtlSeconds();\n\n    default boolean isCacheEnabled() {\n        return getCacheTtlSeconds() &gt; 0;\n    }\n}\n\n\/\/ UserRepository.java: 3\u3064\u306einterface\u3092\u540c\u6642\u306b\u5b9f\u88c5\n\/\/ implements \u30ad\u30fc\u30ef\u30fc\u30c9\u306e\u5f8c\u306b\u30ab\u30f3\u30de\u533a\u5207\u308a\u3067\u5217\u6319\u3059\u308b\npublic class UserRepository implements Serializable, Loggable, Cacheable {\n\n    private static final int TTL = 300; \/\/ 5\u5206\n\n    @Override\n    public String serialize() {\n        return \"{ \\\"type\\\": \\\"UserRepository\\\" }\";\n    }\n\n    @Override\n    public Object deserialize(String data) {\n        \/\/ JSON\u89e3\u6790\u51e6\u7406\uff08\u5b9f\u969b\u306e\u5b9f\u88c5\u3067\u306fJackson\u7b49\u3092\u4f7f\u3046\uff09\n        return new Object();\n    }\n\n    @Override\n    public void log(String message) {\n        System.out.println(\"[UserRepository] \" + message);\n    }\n\n    @Override\n    public String getCacheKey() {\n        return \"user:repository:all\";\n    }\n\n    @Override\n    public int getCacheTtlSeconds() {\n        return TTL;\n    }\n\n    \/\/ default\u30e1\u30bd\u30c3\u30c9\u306f\u305d\u306e\u307e\u307e\u4f7f\u3048\u308b\uff08\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u4e0d\u8981\uff09\n    \/\/ logError(), logInfo(), isCacheEnabled()\u304c\u3059\u3079\u3066\u4f7f\u7528\u53ef\u80fd\n}\n\n\/\/ Main.java\npublic class Main {\n    public static void main(String[] args) {\n        UserRepository repo = new UserRepository();\n\n        repo.logInfo(\"\u30e6\u30fc\u30b6\u30fc\u30c7\u30fc\u30bf\u3092\u53d6\u5f97\u3057\u307e\u3059\");\n\n        if (repo.isCacheEnabled()) {\n            repo.logInfo(\"\u30ad\u30e3\u30c3\u30b7\u30e5\u30ad\u30fc: \" + repo.getCacheKey() + \" TTL: \" + repo.getCacheTtlSeconds() + \"\u79d2\");\n        }\n\n        String data = repo.serialize();\n        repo.logInfo(\"\u30b7\u30ea\u30a2\u30e9\u30a4\u30ba: \" + data);\n    }\n}<\/code><\/pre>\n\n<div style=\"border:2px solid #e74c3c;border-radius:6px;padding:16px 20px;margin:24px 0;background:#fff9f9\"><p style=\"font-weight:bold;color:#e74c3c;margin:0 0 8px\">\u26a0\ufe0f \u540c\u540ddefault\u30e1\u30bd\u30c3\u30c9\u306e\u7af6\u5408\u306b\u6ce8\u610f<\/p><p style=\"margin:0\">\u8907\u6570\u306einterface\u3092\u5b9f\u88c5\u3059\u308b\u3068\u304d\u3001\u540c\u3058\u30e1\u30bd\u30c3\u30c9\u540d\u306edefault\u30e1\u30bd\u30c3\u30c9\u304c\u8907\u6570\u306einterface\u306b\u5b58\u5728\u3059\u308b\u3068\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002\u3053\u306e\u5834\u5408\u306f\u5b9f\u88c5\u30af\u30e9\u30b9\u3067\u5fc5\u305a\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3057\u3001\u300cInterfaceName.super.methodName()\u300d\u306e\u5f62\u3067\u3069\u3061\u3089\u306edefault\u30e1\u30bd\u30c3\u30c9\u3092\u547c\u3076\u304b\u660e\u793a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002<\/p><\/div>\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ \u7af6\u5408\u306e\u89e3\u6c7a\u4f8b\npublic interface InterfaceA {\n    default void hello() { System.out.println(\"Hello from A\"); }\n}\n\npublic interface InterfaceB {\n    default void hello() { System.out.println(\"Hello from B\"); }\n}\n\n\/\/ \u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\uff01 \u2192 \u5fc5\u305a\u30aa\u30fc\u30d0\u30fc\u30e9\u30a4\u30c9\u3067\u89e3\u6c7a\u3059\u308b\npublic class MyClass implements InterfaceA, InterfaceB {\n\n    @Override\n    public void hello() {\n        \/\/ \u3069\u3061\u3089\u304b\u3092\u660e\u793a\u7684\u306b\u547c\u3076\n        InterfaceA.super.hello(); \/\/ \"Hello from A\"\u3092\u547c\u3076\u5834\u5408\n        \/\/ InterfaceB.super.hello(); \/\/ \"Hello from B\"\u3092\u547c\u3076\u5834\u5408\n        \/\/ \u307e\u305f\u306f\u72ec\u81ea\u306e\u51e6\u7406\u3092\u66f8\u304f\n        System.out.println(\"Hello from MyClass\");\n    }\n}<\/code><\/pre>\n\n\n<div class=\"balloon-wrap\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/ceo-sugasawa.jpg\" alt=\"\u4ee3\u8868\u83c5\u6fa4\">\n    <span class=\"balloon-name\">\u4ee3\u8868\u83c5\u6fa4<\/span>\n  <\/div>\n  <div class=\"balloon-body\">\u8907\u6570interface\u3092\u5b9f\u88c5\u3059\u308b\u306e\u306f\u975e\u5e38\u306b\u5f37\u529b\u3067\u3059\u304c\u3001\u300c\u3053\u306e\u30af\u30e9\u30b9\u306f\u4f55\u8005\u304b\u300d\u304c\u5206\u304b\u308a\u306b\u304f\u304f\u306a\u308b\u30ea\u30b9\u30af\u3082\u3042\u308a\u307e\u3059\u3002\u5b9f\u88c5\u3059\u308binterface\u306f5\u500b\u4ee5\u5185\u3092\u76ee\u5b89\u306b\u3057\u3001\u30af\u30e9\u30b9\u304c\u80a5\u5927\u5316\u3057\u3066\u304d\u305f\u3089\u5206\u5272\u3092\u691c\u8a0e\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-07\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">07<\/span>\n  <span class=\"section-label\" style=\"display:block;\">DESIGN PATTERNS<\/span>\n  <span class=\"section-title\" style=\"display:block;\">interface\u306e\u5b9f\u8df5\u7684\u306a\u8a2d\u8a08\u30d1\u30bf\u30fc\u30f3<\/span>\n  <span class=\"section-desc\">\u73fe\u5834\u3067\u4f7f\u3048\u308binterface\u306e\u8a2d\u8a08\u30c6\u30af\u30cb\u30c3\u30af<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">interface\u306e\u57fa\u790e\u3092\u7406\u89e3\u3057\u305f\u3089\u3001\u6b21\u306f\u5b9f\u969b\u306e\u958b\u767a\u73fe\u5834\u3067\u4f7f\u308f\u308c\u308b\u8a2d\u8a08\u30d1\u30bf\u30fc\u30f3\u3092\u5b66\u3073\u307e\u3057\u3087\u3046\u3002\u3053\u3053\u3067\u306f\u7279\u306b\u91cd\u8981\u306a3\u3064\u306e\u30d1\u30bf\u30fc\u30f3\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n\n\n<div class=\"g-flow-row\" style=\"display:flex;flex-wrap:wrap;align-items:center;gap:8px;margin:20px 0;padding:16px;background:#ecf0f1;border-radius:6px\"><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">Strategy Pattern<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">Repository Pattern<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">Command Pattern<\/div><div style=\"color:#3498db;font-size:1.4em;padding:0 4px\">\u2192<\/div><div style=\"background:#3498db;color:#fff;padding:10px 16px;border-radius:4px;font-weight:bold;white-space:nowrap\">\u758e\u7d50\u5408\u306a\u8a2d\u8a08\u3078<\/div><\/div>\n\n\n<h3 class=\"wp-block-heading\">7-1. Strategy Pattern\uff08\u6226\u7565\u30d1\u30bf\u30fc\u30f3\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Strategy Pattern<\/strong>\u306f\u3001\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\uff08\u51e6\u7406\u306e\u6226\u7565\uff09\u3092interface\u3067\u62bd\u8c61\u5316\u3057\u3001\u5b9f\u884c\u6642\u306b\u5207\u308a\u66ff\u3048\u3089\u308c\u308b\u3088\u3046\u306b\u3059\u308b\u30d1\u30bf\u30fc\u30f3\u3067\u3059\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ SortStrategy.java\uff08\u30bd\u30fc\u30c8\u30a2\u30eb\u30b4\u30ea\u30ba\u30e0\u306einterface\uff09\npublic interface SortStrategy {\n    void sort(int[] array);\n\n    \/\/ static\u30d5\u30a1\u30af\u30c8\u30ea\u30e1\u30bd\u30c3\u30c9\u3067\u6226\u7565\u3092\u751f\u6210\n    static SortStrategy bubbleSort() {\n        return array -&gt; {\n            int n = array.length;\n            for (int i = 0; i &lt; n - 1; i++) {\n                for (int j = 0; j &lt; n - i - 1; j++) {\n                    if (array[j] &gt; array[j + 1]) {\n                        int temp = array[j];\n                        array[j] = array[j + 1];\n                        array[j + 1] = temp;\n                    }\n                }\n            }\n        };\n    }\n\n    static SortStrategy quickSort() {\n        return array -&gt; java.util.Arrays.sort(array); \/\/ \u7c21\u7565\u5316\n    }\n}\n\n\/\/ Sorter.java\uff08\u6226\u7565\u3092\u4f7f\u3046\u5074\uff09\npublic class Sorter {\n    private SortStrategy strategy;\n\n    public Sorter(SortStrategy strategy) {\n        this.strategy = strategy;\n    }\n\n    \/\/ \u5b9f\u884c\u6642\u306b\u6226\u7565\u3092\u5909\u66f4\u3067\u304d\u308b\n    public void setStrategy(SortStrategy strategy) {\n        this.strategy = strategy;\n    }\n\n    public int[] sort(int[] array) {\n        int[] copy = array.clone();\n        strategy.sort(copy);\n        return copy;\n    }\n}\n\n\/\/ Main.java\npublic class Main {\n    public static void main(String[] args) {\n        int[] data = {5, 2, 8, 1, 9, 3};\n\n        Sorter sorter = new Sorter(SortStrategy.bubbleSort());\n        int[] result1 = sorter.sort(data);\n\n        \/\/ \u5b9f\u884c\u6642\u306b\u6226\u7565\u3092\u5207\u308a\u66ff\u3048\n        sorter.setStrategy(SortStrategy.quickSort());\n        int[] result2 = sorter.sort(data);\n    }\n}<\/code><\/pre>\n\n\n<h3 class=\"wp-block-heading\">7-2. Repository Pattern\uff08\u30ea\u30dd\u30b8\u30c8\u30ea\u30d1\u30bf\u30fc\u30f3\uff09<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\"><strong>Repository Pattern<\/strong>\u306f\u3001\u30c7\u30fc\u30bf\u30a2\u30af\u30bb\u30b9\u306e\u30ed\u30b8\u30c3\u30af\u3092interface\u3067\u62bd\u8c61\u5316\u3057\u3001\u30c6\u30b9\u30c8\u3057\u3084\u3059\u304f\u30fb\u30c7\u30fc\u30bf\u30bd\u30fc\u30b9\u3092\u5909\u3048\u3084\u3059\u3044\u8a2d\u8a08\u306b\u3059\u308b\u30d1\u30bf\u30fc\u30f3\u3067\u3059\u3002<\/p>\n\n\n<pre style=\"background:#1e1e1e;color:#d4d4d4;padding:20px;border-radius:6px;overflow-x:auto;line-height:1.6;margin:20px 0\"><code>\/\/ User.java\uff08\u30a8\u30f3\u30c6\u30a3\u30c6\u30a3\uff09\npublic class User {\n    private Long id;\n    private String name;\n    private String email;\n\n    public User(Long id, String name, String email) {\n        this.id = id;\n        this.name = name;\n        this.email = email;\n    }\n    \/\/ getter, setter\u7701\u7565\n    public Long getId() { return id; }\n    public String getName() { return name; }\n    public String getEmail() { return email; }\n}\n\n\/\/ UserRepository.java\uff08\u30c7\u30fc\u30bf\u30a2\u30af\u30bb\u30b9\u306einterface\uff09\nimport java.util.List;\nimport java.util.Optional;\n\npublic interface UserRepository {\n    Optional&lt;User&gt; findById(Long id);\n    List&lt;User&gt; findAll();\n    List&lt;User&gt; findByName(String name);\n    User save(User user);\n    void delete(Long id);\n    long count();\n}\n\n\/\/ MySqlUserRepository.java\uff08\u672c\u756a\u7528MySQL\u5b9f\u88c5\uff09\npublic class MySqlUserRepository implements UserRepository {\n    \/\/ MySQL\u3078\u306e\u5b9f\u969b\u306e\u63a5\u7d9a\u30fb\u30af\u30a8\u30ea\u51e6\u7406\n\n    @Override\n    public Optional&lt;User&gt; findById(Long id) {\n        \/\/ SELECT * FROM users WHERE id = ?\n        return Optional.empty(); \/\/ \u5b9f\u969b\u306fDB\u304b\u3089\u53d6\u5f97\n    }\n\n    @Override\n    public List&lt;User&gt; findAll() {\n        \/\/ SELECT * FROM users\n        return List.of(); \/\/ \u5b9f\u969b\u306fDB\u304b\u3089\u53d6\u5f97\n    }\n\n    \/\/ \u4ed6\u306e\u30e1\u30bd\u30c3\u30c9\u3082\u5b9f\u88c5...\n    @Override public List&lt;User&gt; findByName(String name) { return List.of(); }\n    @Override public User save(User user) { return user; }\n    @Override public void delete(Long id) {}\n    @Override public long count() { return 0; }\n}\n\n\/\/ InMemoryUserRepository.java\uff08\u30c6\u30b9\u30c8\u7528\u306e\u30e1\u30e2\u30ea\u5b9f\u88c5\uff09\nimport java.util.*;\n\npublic class InMemoryUserRepository implements UserRepository {\n    private final Map&lt;Long, User&gt; store = new HashMap&lt;&gt;();\n    private long nextId = 1;\n\n    @Override\n    public Optional&lt;User&gt; findById(Long id) {\n        return Optional.ofNullable(store.get(id));\n    }\n\n    @Override\n    public List&lt;User&gt; findAll() {\n        return new ArrayList&lt;&gt;(store.values());\n    }\n\n    @Override\n    public List&lt;User&gt; findByName(String name) {\n        List&lt;User&gt; result = new ArrayList&lt;&gt;();\n        for (User u : store.values()) {\n            if (u.getName().equals(name)) result.add(u);\n        }\n        return result;\n    }\n\n    @Override\n    public User save(User user) {\n        if (user.getId() == null) {\n            User newUser = new User(nextId++, user.getName(), user.getEmail());\n            store.put(newUser.getId(), newUser);\n            return newUser;\n        }\n        store.put(user.getId(), user);\n        return user;\n    }\n\n    @Override\n    public void delete(Long id) { store.remove(id); }\n\n    @Override\n    public long count() { return store.size(); }\n}\n\n\/\/ UserService.java\uff08\u30d3\u30b8\u30cd\u30b9\u30ed\u30b8\u30c3\u30af\u5074\u306finterface\u578b\u3067\u53d7\u3051\u53d6\u308b\uff09\npublic class UserService {\n    private final UserRepository repository;\n\n    \/\/ \u30b3\u30f3\u30b9\u30c8\u30e9\u30af\u30bf\u3067DI\uff08\u4f9d\u5b58\u6027\u6ce8\u5165\uff09\n    public UserService(UserRepository repository) {\n        this.repository = repository;\n    }\n\n    public User registerUser(String name, String email) {\n        \/\/ \u91cd\u8907\u30e1\u30fc\u30eb\u30c1\u30a7\u30c3\u30af\n        List&lt;User&gt; existing = repository.findAll();\n        for (User u : existing) {\n            if (u.getEmail().equals(email)) {\n                throw new IllegalArgumentException(\"\u3053\u306e\u30e1\u30fc\u30eb\u30a2\u30c9\u30ec\u30b9\u306f\u65e2\u306b\u767b\u9332\u3055\u308c\u3066\u3044\u307e\u3059\");\n            }\n        }\n        return repository.save(new User(null, name, email));\n    }\n}<\/code><\/pre>\n\n<div style=\"border:2px solid #27ae60;border-radius:6px;padding:16px 20px;margin:24px 0;background:#f0fff4\"><p style=\"font-weight:bold;color:#27ae60;margin:0 0 8px\">\ud83d\udca1 Repository Pattern\u3068\u30c6\u30b9\u30c8\u306e\u76f8\u6027<\/p><p style=\"margin:0\">UserService\u306e\u30c6\u30b9\u30c8\u3092\u66f8\u304f\u3068\u304d\u3001MySqlUserRepository\u3092\u4f7f\u3046\u3068DB\u306e\u6e96\u5099\u304c\u5fc5\u8981\u3067\u9762\u5012\u3067\u3059\u3002InMemoryUserRepository\u3092\u4f7f\u3048\u3070DB\u306a\u3057\u3067\u77ac\u6642\u306b\u30c6\u30b9\u30c8\u3092\u5b9f\u884c\u3067\u304d\u307e\u3059\u3002interface\u3067\u62bd\u8c61\u5316\u3057\u3066\u3044\u308b\u304a\u304b\u3052\u3067\u3001UserService\u306e\u30b3\u30fc\u30c9\u306f\u4e00\u884c\u3082\u5909\u3048\u305a\u306b\u30c6\u30b9\u30c8\u7528\u306e\u5b9f\u88c5\u306b\u5dee\u3057\u66ff\u3048\u3089\u308c\u307e\u3059\u3002\u3053\u308c\u304c\u300c\u30c6\u30b9\u30c8\u3057\u3084\u3059\u3044\u8a2d\u8a08\u300d\u306e\u6838\u5fc3\u3067\u3059\u3002<\/p><\/div>\n\n<div style=\"border-left:4px solid #95a5a6;padding:12px 16px;margin:20px 0;background:#f8f9fa\"><p style=\"font-weight:bold;margin:0 0 6px\">\ud83d\udcd6 \u7528\u8a9e\u89e3\u8aac: \u30dd\u30ea\u30e2\u30fc\u30d5\u30a3\u30ba\u30e0<\/p><p style=\"margin:0;color:#555\">\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u6307\u5411\u306e\u4e09\u5927\u6982\u5ff5\u306e\u4e00\u3064\uff08\u4ed6\u306f\u30ab\u30d7\u30bb\u30eb\u5316\u30fb\u7d99\u627f\uff09\u3002\u300c\u591a\u614b\u6027\u300d\u3068\u3082\u8a33\u3059\u3002\u540c\u3058\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\u578b\u306e\u5909\u6570\u304c\u3001\u5b9f\u969b\u306b\u306f\u7570\u306a\u308b\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u6307\u3057\u3001\u547c\u3073\u51fa\u3057\u6642\u306b\u5b9f\u969b\u306e\u30af\u30e9\u30b9\u306e\u30e1\u30bd\u30c3\u30c9\u304c\u5b9f\u884c\u3055\u308c\u308b\u4ed5\u7d44\u307f\u3002Notifiable\u578b\u306e\u5909\u6570\u306bEmailNotifier\u3092\u5165\u308c\u3066\u3082\u3001SlackNotifier\u3092\u5165\u308c\u3066\u3082\u3001send()\u3092\u547c\u3079\u3070\u5404\u30af\u30e9\u30b9\u306e\u5b9f\u88c5\u304c\u52d5\u304f\u2014\u2014\u3053\u308c\u304c\u30dd\u30ea\u30e2\u30fc\u30d5\u30a3\u30ba\u30e0\u3067\u3059\u3002<\/p><\/div>\n\n\n<div class=\"balloon-wrap is-right\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/yamazaki-avatar.png\" alt=\"AI\u9b3c\u7ba1\u7406\u5c71\u5d0e\">\n    <span class=\"balloon-name\">AI\u9b3c\u7ba1\u7406\u5c71\u5d0e<\/span>\n  <\/div>\n  <div class=\"balloon-body\">Strategy Pattern\u3068Repository Pattern\u306f\u73fe\u5834\u3067\u6700\u3082\u591a\u304f\u4f7f\u308f\u308c\u308binterface\u306e\u6d3b\u7528\u30d1\u30bf\u30fc\u30f3\u3067\u3059\u3002\u3069\u3061\u3089\u3082interface\u578b\u3067\u4f9d\u5b58\u3092\u53d7\u3051\u53d6\u308b\u3053\u3068\u3067\u3001\u5b9f\u88c5\u306e\u5dee\u3057\u66ff\u3048\u3092\u5bb9\u6613\u306b\u3057\u3066\u3044\u307e\u3059\u3002\u3053\u306e\u8a2d\u8a08\u601d\u60f3\u3092\u300cDIP\uff08\u4f9d\u5b58\u6027\u9006\u8ee2\u306e\u539f\u5247\uff09\u300d\u3068\u547c\u3073\u3001SOLID\u539f\u5247\u306e\u4e00\u3064\u3067\u3059\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<div id=\"sec-08\"><\/div>\n<h2 class=\"section-header-img\" style=\"margin:32px 0 24px;border-radius:8px;overflow:hidden;background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);padding:32px 28px;color:#fff;position:relative;border:none;border-left:none;text-align:left;\">\n  <span class=\"section-number\" style=\"display:block;\">08<\/span>\n  <span class=\"section-label\" style=\"display:block;\">COMMON MISTAKES<\/span>\n  <span class=\"section-title\" style=\"display:block;\">\u3088\u304f\u3042\u308b\u8cea\u554f\u3068\u9593\u9055\u3044<\/span>\n  <span class=\"section-desc\">\u521d\u5fc3\u8005\u304c\u306f\u307e\u308a\u3084\u3059\u3044\u30dd\u30a4\u30f3\u30c8\u3092\u7dcf\u307e\u3068\u3081<\/span>\n<\/h2>\n\n\n\n<p class=\"wp-block-paragraph\">Java\u306einterface\u3092\u5b66\u3076\u904e\u7a0b\u3067\u3001\u591a\u304f\u306e\u4eba\u304c\u540c\u3058\u7591\u554f\u3084\u9593\u9055\u3044\u306b\u3076\u3064\u304b\u308a\u307e\u3059\u3002\u3053\u3053\u3067\u4e00\u62ec\u3057\u3066\u6574\u7406\u3057\u3066\u304a\u304d\u307e\u3057\u3087\u3046\u3002<\/p>\n\n\n<ul style=\"list-style:none;padding:0;margin:16px 0\"><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Q: interface\u306e\u30e1\u30bd\u30c3\u30c9\u306b\u30a2\u30af\u30bb\u30b9\u4fee\u98fe\u5b50\u3092\u66f8\u304b\u306a\u3044\u3068\u3044\u3051\u306a\u3044\uff1f<\/strong> \u2192 \u7701\u7565\u3059\u308b\u3068\u81ea\u52d5\u7684\u306bpublic\u306b\u306a\u308a\u307e\u3059\u3002private\u3068protected\u306f\u4f7f\u3048\u307e\u305b\u3093\uff08Java 9\u304b\u3089private\u306f\u4f7f\u7528\u53ef\u80fd\uff09\u3002<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Q: interface\u306e\u5909\u6570\uff08\u30d5\u30a3\u30fc\u30eb\u30c9\uff09\u306f\u5909\u66f4\u3067\u304d\u308b\uff1f<\/strong> \u2192 \u3067\u304d\u307e\u305b\u3093\u3002interface\u306e\u30d5\u30a3\u30fc\u30eb\u30c9\u306f\u6697\u9ed9\u7684\u306bpublic static final\u306a\u306e\u3067\u3001\u5b9a\u6570\u3068\u3057\u3066\u6271\u308f\u308c\u307e\u3059\u3002<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Q: interface\u3092extends\u3067\u7d99\u627f\u3067\u304d\u308b\uff1f<\/strong> \u2192 \u3067\u304d\u307e\u3059\u3002interface\u304cinterface\u3092\u7d99\u627f\u3059\u308b\u5834\u5408\u306fextends\u3092\u4f7f\u3044\u307e\u3059\uff08\u8907\u6570\u7d99\u627f\u3082\u53ef\uff09\u3002<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Q: interface\u3092\u5b9f\u88c5\u3057\u305f\u30af\u30e9\u30b9\u304c\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3067\u304d\u306a\u3044\uff1f<\/strong> \u2192 interface\u3092\u5b9f\u88c5\u3057\u305f\u30af\u30e9\u30b9\u306f\u666e\u901a\u306bnew\u3067\u304d\u307e\u3059\u3002\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u751f\u6210\u3067\u304d\u306a\u3044\u306e\u306finterface\u81ea\u4f53\u3067\u3059\u3002<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Q: @FunctionalInterface\u3068\u306f\uff1f<\/strong> \u2192 \u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u304c1\u3064\u3060\u3051\u306einterface\u3092FunctionalInterface\u3068\u547c\u3073\u307e\u3059\u3002Lambda\u5f0f\uff08\u30e9\u30e0\u30c0\u5f0f\uff09\u3067\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002<\/li><li style=\"margin-bottom:8px\"><span style=\"color:#e74c3c;margin-right:8px\">\u2713<\/span><strong>Q: interface\u306b\u5b9a\u6570\u3092\u5b9a\u7fa9\u3059\u308b\u306e\u306f\u3088\u3044\u8a2d\u8a08\uff1f<\/strong> \u2192 \u300cConstant Interface\u30a2\u30f3\u30c1\u30d1\u30bf\u30fc\u30f3\u300d\u3068\u547c\u3070\u308c\u3001\u63a8\u5968\u3055\u308c\u307e\u305b\u3093\u3002\u5b9a\u6570\u306f\u5c02\u7528\u306e\u30af\u30e9\u30b9\uff08Enum\u3084final\u30af\u30e9\u30b9\uff09\u3067\u5b9a\u7fa9\u3059\u308b\u65b9\u304c\u3088\u3044\u3067\u3059\u3002<\/li><\/ul>\n\n\n<p class=\"wp-block-paragraph\">\u7279\u306b\u521d\u5fc3\u8005\u304c\u6df7\u4e71\u3057\u3084\u3059\u3044\u306e\u304c<strong>\u300cinterface\u3068abstract class\u306f\u3069\u3061\u3089\u3092\u5148\u306b\u5b66\u3076\u3079\u304d\u304b\u300d<\/strong>\u3068\u3044\u3046\u70b9\u3067\u3059\u304c\u3001\u7b54\u3048\u306f<strong>interface<\/strong>\u3092\u5148\u306b\u5b66\u3076\u3053\u3068\u3092\u304a\u3059\u3059\u3081\u3057\u307e\u3059\u3002\u73fe\u4ee3\u306eJava\u958b\u767a\u3067\u306finterface\u306e\u4f7f\u7528\u983b\u5ea6\u304c\u5727\u5012\u7684\u306b\u9ad8\u304f\u3001abstract class\u306f\u7279\u5b9a\u306e\u5834\u9762\u306b\u9650\u3089\u308c\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n\n\n\n<div class=\"balloon-wrap\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/ceo-sugasawa.jpg\" alt=\"\u4ee3\u8868\u83c5\u6fa4\">\n    <span class=\"balloon-name\">\u4ee3\u8868\u83c5\u6fa4<\/span>\n  <\/div>\n  <div class=\"balloon-body\">\u300c\u3088\u304f\u3042\u308b\u9593\u9055\u3044\u300d\u306e\u4e2d\u3067\u3082\u7279\u306b\u6ce8\u610f\u3057\u3066\u307b\u3057\u3044\u306e\u304c\u300cConstant Interface\u30a2\u30f3\u30c1\u30d1\u30bf\u30fc\u30f3\u300d\u3067\u3059\u3002interface\u3092\u5b9a\u6570\u306e\u7f6e\u304d\u5834\u306b\u3059\u308b\u306e\u306f\u3001\u5c06\u6765\u7684\u306a\u5909\u66f4\u30b3\u30b9\u30c8\u3092\u9ad8\u3081\u308b\u8a2d\u8a08\u3067\u3059\u3002\u5b9a\u6570\u306fEnum\u307e\u305f\u306ffinal\u306a\u30e6\u30fc\u30c6\u30a3\u30ea\u30c6\u30a3\u30af\u30e9\u30b9\u306b\u7f6e\u304f\u2014\u2014\u3053\u306e\u7fd2\u6163\u3092\u6700\u521d\u304b\u3089\u8eab\u306b\u3064\u3051\u3066\u304f\u3060\u3055\u3044\u3002<\/div>\n<\/div>\n\n\n<div style=\"margin:48px 0 8px;display:flex;gap:12px;justify-content:center;flex-wrap:wrap;\"><a href=\"https:\/\/aikanri.genai-ai.co.jp\/seminar2-blog\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_content=cc-java-interface&#038;blog_slug=cc-java-interface\" target=\"_blank\" rel=\"noopener\" aria-label=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff08\u7121\u6599\u30fb1on1\u30fb60\u5206\uff09\u306e\u4e88\u7d04\u753b\u9762\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_seminar_claude_code_2026.jpg\" alt=\"Claude Code \u5b8c\u5168\u89e3\u8aac\u30bb\u30df\u30ca\u30fc\uff5c\u7d4c\u55b6\u8005\u30fb\u4f1a\u793e\u5f79\u54e1\u5c02\u7528 1on1 60\u5206 \u7121\u6599\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&#038;utm_medium=h2banner&#038;utm_campaign=cc-java-interface&#038;utm_content=h2-banner-kanri\" target=\"_blank\" rel=\"noopener\" aria-label=\"AI\u9b3c\u7ba1\u7406 \u516c\u5f0f\u30b5\u30a4\u30c8\u3078\" style=\"flex:1 1 280px;max-width:360px;text-decoration:none;\"><img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/05\/cta_blog_1to1.jpg\" alt=\"Claude Code\u3092\u7d4c\u55b6\u306b\u6d3b\u304b\u3057\u305f\u3044\u65b9\u3078 \u2014 AI\u9b3c\u7ba1\u7406\" style=\"width:100%;height:auto;border-radius:8px;display:block;\"><\/a><\/div>\n\n\n<h2 class=\"wp-block-heading\" id=\"faq\">\u3088\u304f\u3042\u308b\u8cea\u554f<\/h2>\n\n\n\n<h3 class=\"wp-block-heading\">Q. Java\u306einterface\u3068CSharp\u306einterface\u306b\u9055\u3044\u306f\u3042\u308a\u307e\u3059\u304b\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A. \u57fa\u672c\u7684\u306a\u6982\u5ff5\u306f\u540c\u3058\u3067\u3059\u304c\u3001\u3044\u304f\u3064\u304b\u9055\u3044\u304c\u3042\u308a\u307e\u3059\u3002Java 8\u4ee5\u964d\u306fdefault\u30e1\u30bd\u30c3\u30c9\u3068static\u30e1\u30bd\u30c3\u30c9\u3092interface\u306b\u5b9a\u7fa9\u3067\u304d\u307e\u3059\u304c\u3001C#\uff08C# 8.0\u4ee5\u524d\uff09\u306f\u3067\u304d\u307e\u305b\u3093\u3067\u3057\u305f\u3002C# 8.0\u4ee5\u964d\u306fdefault interface methods\u304c\u8ffd\u52a0\u3055\u308c\u3001Java\u306edefault\u30e1\u30bd\u30c3\u30c9\u3068\u307b\u307c\u2160\u540c\u69d8\u306e\u6a5f\u80fd\u304c\u4f7f\u3048\u308b\u3088\u3046\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u307e\u305f\u3001Java\u306finterface\u306bprivate\u30e1\u30bd\u30c3\u30c9\u3092\u5b9a\u7fa9\u3067\u304d\u307e\u3059\uff08Java 9\u4ee5\u964d\uff09\u304c\u3001C# 8.0\u4ee5\u964d\u3082\u540c\u69d8\u3067\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q. interface\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u3059\u3079\u3066\u5b9f\u88c5\u3057\u306a\u3044\u3068\u3069\u3046\u306a\u308a\u307e\u3059\u304b\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A. \u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002interface\u306e\u3059\u3079\u3066\u306e\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u3092\u5b9f\u88c5\u3057\u306a\u3044\u30af\u30e9\u30b9\u306f\u3001\u81ea\u8eab\u3082abstract\u30af\u30e9\u30b9\u3068\u3057\u3066\u5ba3\u8a00\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u305f\u3068\u3048\u3070implements\u5f8c\u306b\u4e00\u90e8\u306e\u30e1\u30bd\u30c3\u30c9\u3057\u304b\u5b9f\u88c5\u3057\u306a\u3044\u5834\u5408\u3001abstract class\u5ba3\u8a00\u3092\u8ffd\u52a0\u3059\u308b\u3053\u3068\u3067\u30b3\u30f3\u30d1\u30a4\u30eb\u3092\u901a\u305b\u307e\u3059\u3002\u305f\u3060\u3057\u305d\u306e\u5834\u5408\u3001\u305d\u306e\u30af\u30e9\u30b9\u81ea\u4f53\u3082\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u751f\u6210\u4e0d\u53ef\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q. functionalInterface\u3068Lambda\u5f0f\u306finterface\u3068\u95a2\u4fc2\u3042\u308a\u307e\u3059\u304b\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A. \u6df1\u304f\u95a2\u4fc2\u3057\u3066\u3044\u307e\u3059\u3002@FunctionalInterface\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u306f\u300c\u3053\u306einterface\u306f\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u304c1\u3064\u3060\u3051\u300d\u3068\u3044\u3046\u5236\u7d04\u3092\u5ba3\u8a00\u3059\u308b\u3082\u306e\u3067\u3001Lambda\u5f0f\uff08\u533f\u540d\u95a2\u6570\uff09\u3092\u4f7f\u3063\u3066\u7c21\u6f54\u306b\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002\u305f\u3068\u3048\u3070Runnable\uff08run()\u304c1\u3064\u3060\u3051\uff09\u306fFunctionalInterface\u3067\u3001new Thread(() -> System.out.println(\"Hello\"))\u306e\u3088\u3046\u306b\u8a18\u8ff0\u3067\u304d\u307e\u3059\u3002Java 8\u3067\u5c0e\u5165\u3055\u308c\u305fStream API\u3082FunctionalInterface\u3092\u591a\u7528\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q. interface\u3092\u5b9f\u88c5\u3057\u305f\u30af\u30e9\u30b9\u3092interface\u578b\u3067\u6271\u3046\u30e1\u30ea\u30c3\u30c8\u306f\u4f55\u3067\u3059\u304b\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A. \u4e3b\u306a\u30e1\u30ea\u30c3\u30c8\u306f3\u3064\u3067\u3059\u3002\u2460\u4f9d\u5b58\u95a2\u4fc2\u306e\u758e\u7d50\u5408\u5316\uff1a\u547c\u3073\u51fa\u3057\u5074\u306f\u5b9f\u88c5\u30af\u30e9\u30b9\u3092\u77e5\u3089\u306a\u304f\u3066\u3088\u3044\u305f\u3081\u3001\u5b9f\u88c5\u3092\u5dee\u3057\u66ff\u3048\u3066\u3082\u547c\u3073\u51fa\u3057\u5074\u3092\u4fee\u6b63\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u305b\u3093\u3002\u2461\u30c6\u30b9\u30c8\u306e\u3057\u3084\u3059\u3055\uff1a\u672c\u756a\u7528\u5b9f\u88c5\u306e\u4ee3\u308f\u308a\u306b\u30c6\u30b9\u30c8\u7528\u306e\u5b9f\u88c5\uff08\u30e2\u30c3\u30af\uff09\u3092\u6e21\u3059\u3053\u3068\u3067\u3001\u5916\u90e8\u4f9d\u5b58\u306a\u3057\u306e\u30e6\u30cb\u30c3\u30c8\u30c6\u30b9\u30c8\u304c\u66f8\u3051\u307e\u3059\u3002\u2462\u30dd\u30ea\u30e2\u30fc\u30d5\u30a3\u30ba\u30e0\u306e\u6d3b\u7528\uff1ainterface\u578b\u306eList\u306b\u8907\u6570\u306e\u5b9f\u88c5\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5165\u308c\u3066\u4e00\u62ec\u51e6\u7406\u3067\u304d\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">Q. Java 9\u4ee5\u964d\u3067interface\u306b\u8ffd\u52a0\u3055\u308c\u305f\u6a5f\u80fd\u306f\u3042\u308a\u307e\u3059\u304b\uff1f<\/h3>\n\n\n\n<p class=\"wp-block-paragraph\">A. Java 9\u3067private\u30e1\u30bd\u30c3\u30c9\u3068private static\u30e1\u30bd\u30c3\u30c9\u304cinterface\u306b\u5b9a\u7fa9\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3053\u308c\u306b\u3088\u308a\u3001default\u30e1\u30bd\u30c3\u30c9\u540c\u58eb\u3067\u5171\u901a\u3059\u308b\u51e6\u7406\u3092private\u30e1\u30bd\u30c3\u30c9\u306b\u5207\u308a\u51fa\u3057\u3066\u30b3\u30fc\u30c9\u306e\u91cd\u8907\u3092\u907f\u3051\u3089\u308c\u307e\u3059\u3002\u305f\u3068\u3048\u3070\u8907\u6570\u306edefault\u30e1\u30bd\u30c3\u30c9\u304c\u540c\u3058\u30d8\u30eb\u30d1\u30fc\u51e6\u7406\u3092\u4f7f\u3046\u5834\u5408\u3001\u305d\u306e\u30ed\u30b8\u30c3\u30af\u3092private\u30e1\u30bd\u30c3\u30c9\u306b\u96c6\u7d04\u3067\u304d\u307e\u3059\u3002interface\u306e\u5916\u304b\u3089\u306fprivate\u30e1\u30bd\u30c3\u30c9\u306f\u547c\u3073\u51fa\u305b\u306a\u3044\u70b9\u306f\u901a\u5e38\u30af\u30e9\u30b9\u3068\u540c\u3058\u3067\u3059\u3002<\/p>\n\n\n\n<script type=\"application\/ld+json\">\n{\n  \"@context\": \"https:\/\/schema.org\",\n  \"@type\": \"FAQPage\",\n  \"mainEntity\": [\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Java\u306einterface\u3068CSharp\u306einterface\u306b\u9055\u3044\u306f\u3042\u308a\u307e\u3059\u304b\uff1f\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"\u57fa\u672c\u7684\u306a\u6982\u5ff5\u306f\u540c\u3058\u3067\u3059\u304c\u3001\u3044\u304f\u3064\u304b\u9055\u3044\u304c\u3042\u308a\u307e\u3059\u3002Java 8\u4ee5\u964d\u306fdefault\u30e1\u30bd\u30c3\u30c9\u3068static\u30e1\u30bd\u30c3\u30c9\u3092interface\u306b\u5b9a\u7fa9\u3067\u304d\u307e\u3059\u304c\u3001C#\uff08C# 8.0\u4ee5\u524d\uff09\u306f\u3067\u304d\u307e\u305b\u3093\u3067\u3057\u305f\u3002C# 8.0\u4ee5\u964d\u306fdefault interface methods\u304c\u8ffd\u52a0\u3055\u308c\u3001Java\u306edefault\u30e1\u30bd\u30c3\u30c9\u3068\u307b\u307c\u2160\u540c\u69d8\u306e\u6a5f\u80fd\u304c\u4f7f\u3048\u308b\u3088\u3046\u306b\u306a\u3063\u3066\u3044\u307e\u3059\u3002\u307e\u305f\u3001Java\u306finterface\u306bprivate\u30e1\u30bd\u30c3\u30c9\u3092\u5b9a\u7fa9\u3067\u304d\u307e\u3059\uff08Java 9\u4ee5\u964d\uff09\u304c\u3001C# 8.0\u4ee5\u964d\u3082\u540c\u69d8\u3067\u3059\u3002\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"interface\u306e\u30e1\u30bd\u30c3\u30c9\u3092\u3059\u3079\u3066\u5b9f\u88c5\u3057\u306a\u3044\u3068\u3069\u3046\u306a\u308a\u307e\u3059\u304b\uff1f\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"\u30b3\u30f3\u30d1\u30a4\u30eb\u30a8\u30e9\u30fc\u306b\u306a\u308a\u307e\u3059\u3002interface\u306e\u3059\u3079\u3066\u306e\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u3092\u5b9f\u88c5\u3057\u306a\u3044\u30af\u30e9\u30b9\u306f\u3001\u81ea\u8eab\u3082abstract\u30af\u30e9\u30b9\u3068\u3057\u3066\u5ba3\u8a00\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u3059\u3002\u305f\u3068\u3048\u3070implements\u5f8c\u306b\u4e00\u90e8\u306e\u30e1\u30bd\u30c3\u30c9\u3057\u304b\u5b9f\u88c5\u3057\u306a\u3044\u5834\u5408\u3001abstract class\u5ba3\u8a00\u3092\u8ffd\u52a0\u3059\u308b\u3053\u3068\u3067\u30b3\u30f3\u30d1\u30a4\u30eb\u3092\u901a\u305b\u307e\u3059\u3002\u305f\u3060\u3057\u305d\u306e\u5834\u5408\u3001\u305d\u306e\u30af\u30e9\u30b9\u81ea\u4f53\u3082\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u751f\u6210\u4e0d\u53ef\u306b\u306a\u308a\u307e\u3059\u3002\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"functionalInterface\u3068Lambda\u5f0f\u306finterface\u3068\u95a2\u4fc2\u3042\u308a\u307e\u3059\u304b\uff1f\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"\u6df1\u304f\u95a2\u4fc2\u3057\u3066\u3044\u307e\u3059\u3002@FunctionalInterface\u30a2\u30ce\u30c6\u30fc\u30b7\u30e7\u30f3\u306f\u300c\u3053\u306einterface\u306f\u62bd\u8c61\u30e1\u30bd\u30c3\u30c9\u304c1\u3064\u3060\u3051\u300d\u3068\u3044\u3046\u5236\u7d04\u3092\u5ba3\u8a00\u3059\u308b\u3082\u306e\u3067\u3001Lambda\u5f0f\uff08\u533f\u540d\u95a2\u6570\uff09\u3092\u4f7f\u3063\u3066\u7c21\u6f54\u306b\u5b9f\u88c5\u3067\u304d\u307e\u3059\u3002\u305f\u3068\u3048\u3070Runnable\uff08run()\u304c1\u3064\u3060\u3051\uff09\u306fFunctionalInterface\u3067\u3001new Thread(() -> System.out.println(\\\"Hello\\\"))\u306e\u3088\u3046\u306b\u8a18\u8ff0\u3067\u304d\u307e\u3059\u3002Java 8\u3067\u5c0e\u5165\u3055\u308c\u305fStream API\u3082FunctionalInterface\u3092\u591a\u7528\u3057\u3066\u3044\u307e\u3059\u3002\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"interface\u3092\u5b9f\u88c5\u3057\u305f\u30af\u30e9\u30b9\u3092interface\u578b\u3067\u6271\u3046\u30e1\u30ea\u30c3\u30c8\u306f\u4f55\u3067\u3059\u304b\uff1f\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"\u4e3b\u306a\u30e1\u30ea\u30c3\u30c8\u306f3\u3064\u3067\u3059\u3002\u2460\u4f9d\u5b58\u95a2\u4fc2\u306e\u758e\u7d50\u5408\u5316\uff1a\u547c\u3073\u51fa\u3057\u5074\u306f\u5b9f\u88c5\u30af\u30e9\u30b9\u3092\u77e5\u3089\u306a\u304f\u3066\u3088\u3044\u305f\u3081\u3001\u5b9f\u88c5\u3092\u5dee\u3057\u66ff\u3048\u3066\u3082\u547c\u3073\u51fa\u3057\u5074\u3092\u4fee\u6b63\u3059\u308b\u5fc5\u8981\u304c\u3042\u308a\u307e\u305b\u3093\u3002\u2461\u30c6\u30b9\u30c8\u306e\u3057\u3084\u3059\u3055\uff1a\u672c\u756a\u7528\u5b9f\u88c5\u306e\u4ee3\u308f\u308a\u306b\u30c6\u30b9\u30c8\u7528\u306e\u5b9f\u88c5\uff08\u30e2\u30c3\u30af\uff09\u3092\u6e21\u3059\u3053\u3068\u3067\u3001\u5916\u90e8\u4f9d\u5b58\u306a\u3057\u306e\u30e6\u30cb\u30c3\u30c8\u30c6\u30b9\u30c8\u304c\u66f8\u3051\u307e\u3059\u3002\u2462\u30dd\u30ea\u30e2\u30fc\u30d5\u30a3\u30ba\u30e0\u306e\u6d3b\u7528\uff1ainterface\u578b\u306eList\u306b\u8907\u6570\u306e\u5b9f\u88c5\u30af\u30e9\u30b9\u306e\u30a4\u30f3\u30b9\u30bf\u30f3\u30b9\u3092\u5165\u308c\u3066\u4e00\u62ec\u51e6\u7406\u3067\u304d\u307e\u3059\u3002\"\n      }\n    },\n    {\n      \"@type\": \"Question\",\n      \"name\": \"Java 9\u4ee5\u964d\u3067interface\u306b\u8ffd\u52a0\u3055\u308c\u305f\u6a5f\u80fd\u306f\u3042\u308a\u307e\u3059\u304b\uff1f\",\n      \"acceptedAnswer\": {\n        \"@type\": \"Answer\",\n        \"text\": \"Java 9\u3067private\u30e1\u30bd\u30c3\u30c9\u3068private static\u30e1\u30bd\u30c3\u30c9\u304cinterface\u306b\u5b9a\u7fa9\u3067\u304d\u308b\u3088\u3046\u306b\u306a\u308a\u307e\u3057\u305f\u3002\u3053\u308c\u306b\u3088\u308a\u3001default\u30e1\u30bd\u30c3\u30c9\u540c\u58eb\u3067\u5171\u901a\u3059\u308b\u51e6\u7406\u3092private\u30e1\u30bd\u30c3\u30c9\u306b\u5207\u308a\u51fa\u3057\u3066\u30b3\u30fc\u30c9\u306e\u91cd\u8907\u3092\u907f\u3051\u3089\u308c\u307e\u3059\u3002\u305f\u3068\u3048\u3070\u8907\u6570\u306edefault\u30e1\u30bd\u30c3\u30c9\u304c\u540c\u3058\u30d8\u30eb\u30d1\u30fc\u51e6\u7406\u3092\u4f7f\u3046\u5834\u5408\u3001\u305d\u306e\u30ed\u30b8\u30c3\u30af\u3092private\u30e1\u30bd\u30c3\u30c9\u306b\u96c6\u7d04\u3067\u304d\u307e\u3059\u3002interface\u306e\u5916\u304b\u3089\u306fprivate\u30e1\u30bd\u30c3\u30c9\u306f\u547c\u3073\u51fa\u305b\u306a\u3044\u70b9\u306f\u901a\u5e38\u30af\u30e9\u30b9\u3068\u540c\u3058\u3067\u3059\u3002\"\n      }\n    }\n  ]\n}\n<\/script>\n\n\n\n<div class=\"balloon-wrap is-right\">\n  <div class=\"balloon-icon\">\n    <img decoding=\"async\" src=\"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-content\/uploads\/2026\/04\/yamazaki-avatar.png\" alt=\"AI\u9b3c\u7ba1\u7406\u5c71\u5d0e\">\n    <span class=\"balloon-name\">AI\u9b3c\u7ba1\u7406\u5c71\u5d0e<\/span>\n  <\/div>\n  <div class=\"balloon-body\">Java\u306einterface\u306fSpring Framework\u3084Dagger\u7b49\u306e\u4e3b\u8981\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u3067\u3082\u30d5\u30eb\u6d3b\u7528\u3055\u308c\u3066\u3044\u307e\u3059\u3002interface\u3092\u3057\u3063\u304b\u308a\u7406\u89e3\u3057\u3066\u3044\u308b\u3068\u3001\u30d5\u30ec\u30fc\u30e0\u30ef\u30fc\u30af\u306e\u8a2d\u8a08\u601d\u60f3\u304c\u8aad\u3081\u308b\u3088\u3046\u306b\u306a\u308a\u3001\u30a8\u30e9\u30fc\u306e\u539f\u56e0\u7279\u5b9a\u3082\u683c\u6bb5\u306b\u901f\u304f\u306a\u308a\u307e\u3059\u3002\u307e\u305a\u306f\u4eca\u65e5\u304b\u3089\u30b3\u30fc\u30c9\u306binterface\u30921\u3064\u8ffd\u52a0\u3059\u308b\u7df4\u7fd2\u3092\u59cb\u3081\u3066\u307f\u3066\u304f\u3060\u3055\u3044\u3002<\/div>\n<\/div>\n\n\n\n<p style=\"font-size:15px;line-height:1.8;color:#333;margin:0 0 12px;\">\nJava\u306einterface\u3092\u7406\u89e3\u3057\u305f\u3089\u3001\u6b21\u306fAI\u3092\u4f7f\u3063\u3066Java\u958b\u767a\u306e\u751f\u7523\u6027\u309210\u500d\u306b\u3059\u308b\u65b9\u6cd5\u3092\u5b66\u3073\u307e\u305b\u3093\u304b\uff1f\n<strong>AI\u9b3c\u7ba1\u7406<\/strong>\u3067\u306f\u3001Claude Code\u3092\u6d3b\u7528\u3057\u3066\u696d\u52d9\u30b3\u30fc\u30c9\u306e\u81ea\u52d5\u751f\u6210\u30fb\u30ec\u30d3\u30e5\u30fc\u30fb\u30ea\u30d5\u30a1\u30af\u30bf\u30ea\u30f3\u30b0\u3092\u5b9f\u8df5\u3059\u308b\u30ce\u30a6\u30cf\u30a6\u3092\u63d0\u4f9b\u3057\u3066\u3044\u307e\u3059\u3002\n<\/p>\n\n<div style=\"background:linear-gradient(135deg,#1a1a1a 0%,#2a1015 100%);border-radius:16px;padding:36px 32px;margin:48px 0 16px;color:#fff;\">\n  <p style=\"font-size:13px;font-weight:700;color:#dc2626;letter-spacing:2px;margin:0 0 12px;\">NEXT STEP<\/p>\n  <p style=\"font-size:22px;font-weight:800;line-height:1.5;margin:0 0 20px;\">\u3053\u306e\u8a18\u4e8b\u306e\u5185\u5bb9\u3092\u3001\u3042\u306a\u305f\u306e\u30d3\u30b8\u30cd\u30b9\u3067<br>\u5b9f\u8df5\u3057\u3066\u307f\u307e\u305b\u3093\u304b\uff1f<\/p>\n  <div style=\"background:rgba(255,255,255,0.06);border:1px solid rgba(255,255,255,0.12);border-radius:12px;padding:24px;max-width:560px;margin:0 auto;\">\n    <p style=\"font-size:13px;color:#dc2626;font-weight:700;margin:0 0 8px;\">AI\u6d3b\u7528\u3092\u81ea\u793e\u3067\u56de\u305b\u308b\u3088\u3046\u306b\u306a\u308a\u305f\u3044\u65b9\u3078<\/p>\n    <p style=\"font-size:20px;font-weight:800;margin:0 0 12px;\">AI\u9b3c\u7ba1\u7406<\/p>\n    <p style=\"font-size:14px;color:rgba(255,255,255,0.75);margin:0 0 20px;line-height:1.7;\">Claude Code\u30fbCowork\u5c0e\u5165\u652f\u63f4\u304b\u3089\u696d\u52d9\u8a2d\u8a08\u30fb\u793e\u5185\u6d78\u900f\u307e\u3067\u5b9f\u8df5\u30d9\u30fc\u30b9\u3067\u4f34\u8d70\u3002\u300c\u81ea\u793e\u3067\u56de\u305b\u308b\u7d44\u7e54\u300d\u309290\u65e5\u3067\u4f5c\u308b\u7d4c\u55b6\u8005\u5411\u3051\u30c8\u30ec\u30fc\u30cb\u30f3\u30b0\u3002<\/p>\n    <div style=\"text-align:center;\">\n      <a href=\"https:\/\/aikanri.genai-ai.co.jp\/?utm_source=blog&utm_medium=article&utm_campaign=cc-java-interface&utm_content=next-step-cta\" target=\"_blank\" rel=\"noopener\" style=\"display:inline-block;background:#dc2626;color:#fff;font-weight:700;font-size:15px;padding:14px 32px;border-radius:30px;text-decoration:none;\">AI\u9b3c\u7ba1\u7406\u3092\u8a73\u3057\u304f\u898b\u308b \u2192<\/a>\n    <\/div>\n  <\/div>\n<\/div>\n\n\n","protected":false},"excerpt":{"rendered":"<p>Java\u306einterface\uff08\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\uff09\u306e\u4f7f\u3044\u65b9\u3092\u30b3\u30fc\u30c9\u4f8b\u4ed8\u304d\u3067\u5b8c\u5168\u89e3\u8aac\u3002implements\u306b\u3088\u308b\u5b9f\u88c5\u3001default\u30e1\u30bd\u30c3\u30c9\u30fbstatic\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u5206\u3051\u3001\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3001\u591a\u91cd\u7d99\u627f\u306e\u5b9f\u73fe\u65b9\u6cd5\u307e\u3067\u521d\u5fc3\u8005\u5411\u3051\u306b\u4e01\u5be7\u306b\u8aac\u660e\u3057\u307e\u3059\u3002<\/p>\n","protected":false},"author":1,"featured_media":18385,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"sitemap_hide":"","_veu_custom_css":"","vkexunit_cta_each_option":"","footnotes":"","rank_math_description":"Java\u306einterface\uff08\u30a4\u30f3\u30bf\u30fc\u30d5\u30a7\u30fc\u30b9\uff09\u306e\u4f7f\u3044\u65b9\u3092\u30b3\u30fc\u30c9\u4f8b\u4ed8\u304d\u3067\u5b8c\u5168\u89e3\u8aac\u3002implements\u306b\u3088\u308b\u5b9f\u88c5\u3001default\u30e1\u30bd\u30c3\u30c9\u30fbstatic\u30e1\u30bd\u30c3\u30c9\u306e\u4f7f\u3044\u5206\u3051\u3001\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3001\u591a\u91cd\u7d99\u627f\u306e\u5b9f\u73fe\u65b9\u6cd5\u307e\u3067\u521d\u5fc3\u8005\u5411\u3051\u306b\u4e01\u5be7\u306b\u8aac\u660e\u3057\u307e\u3059\u3002","rank_math_focus_keyword":"Java interface","rank_math_title":"\u30102026\u5e747\u6708\u6700\u65b0\u3011Java\u306einterface\u3068\u306f\uff1f\u4f7f\u3044\u65b9\u30fb\u5b9f\u88c5\u65b9\u6cd5\u30fb\u62bd\u8c61\u30af\u30e9\u30b9\u3068\u306e\u9055\u3044\u3092\u30b3\u30fc\u30c9\u4f8b\u4ed8\u304d\u3067\u5b8c\u5168\u89e3\u8aac","pending_rewrite_html":"","pending_rewrite_id":"","pending_rewrite_kw":"","pending_rewrite_at":"","pending_rewrite_source":"","pending_rewrite_brief":"","pending_rewrite_evidence":"","approved_rewrite_html":"","approved_rewrite_id":"","approved_rewrite_kw":"","approved_rewrite_at":"","approved_rewrite_by":"","approved_rewrite_brief":"","approved_rewrite_evidence":"","rewrite_tracker_baseline":"","rewrite_tracker_7day":"","rewrite_tracker_14day":"","rewrite_tracker_30day":"","rewrite_tracker_notified":""},"categories":[2],"tags":[],"class_list":["post-18386","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-claude-tips"],"_links":{"self":[{"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/posts\/18386","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/comments?post=18386"}],"version-history":[{"count":2,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/posts\/18386\/revisions"}],"predecessor-version":[{"id":18405,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/posts\/18386\/revisions\/18405"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/media\/18385"}],"wp:attachment":[{"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/media?parent=18386"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/categories?post=18386"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/genai-ai.co.jp\/ai-kanri\/wp-json\/wp\/v2\/tags?post=18386"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}