{"id":1934,"date":"2010-12-06T15:29:33","date_gmt":"2010-12-06T06:29:33","guid":{"rendered":"http:\/\/blog.bitmeister.jp\/?p=1934"},"modified":"2010-12-06T21:08:51","modified_gmt":"2010-12-06T12:08:51","slug":"java%e3%81%aeprotected%e3%81%ae%e6%84%8f%e5%91%b3","status":"publish","type":"post","link":"https:\/\/blog.bitmeister.jp\/?p=1934","title":{"rendered":"Java\u306eprotected\u306e\u610f\u5473"},"content":{"rendered":"<p>Java\u306e\u30a2\u30af\u30bb\u30b9\u4fee\u98fe\u5b50protected\u3067\u5c11\u3057\u30cf\u30de\u3063\u305f\u306e\u3067\u3001\u8abf\u3079\u305f\u5185\u5bb9\u3092\u30e1\u30e2\u3057\u3066\u304a\u304d\u307e\u3059\u3002<\/p>\n<p>\u901a\u5e38\u3001protected\u3068\u6307\u5b9a\u3055\u308c\u305f\u30d5\u30a3\u30fc\u30eb\u30c9\u3084\u30e1\u30bd\u30c3\u30c9\u306f\u300c\u540c\u4e00package\u5185\u3068\u3001\u305d\u306e\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u305f\u30b5\u30d6\u30af\u30e9\u30b9\u5185\u304b\u3089\u30a2\u30af\u30bb\u30b9\u3067\u304d\u308b\u300d\u3068\u8aac\u660e\u3055\u308c\u307e\u3059\u3002\u79c1\u81ea\u8eab\u3082\u540c\u69d8\u306e\u7406\u89e3\u3060\u3063\u305f\u306e\u3067\u3059\u304c\u3001\u6b21\u306e\u3088\u3046\u306a\u30b1\u30fc\u30b9\u3067\u4e88\u60f3\u5916\u306e\u6319\u52d5\u3068\u306a\u308a\u307e\u3057\u305f\u3002<\/p>\n<p>\u30af\u30e9\u30b9Base\u3068Child\u304c\u5225\u306epackage\u306b\u5c5e\u3059\u308b\u5834\u5408\u3001<\/p>\n<pre class=\"java\" name=\"code\">\r\npackage base;\r\n\r\npublic class Base {\r\n\t\r\n\tprotected void baseMethod() {\r\n\t\tSystem.out.println(\"Base method.\");\r\n\t}\r\n\t\r\n}\r\n<\/pre>\n<pre class=\"java\" name=\"code\">\r\npackage child;\r\n\r\nimport base.Base;\r\n\r\npublic class Child extends Base {\r\n\r\n\tpublic void childMethod(Base base) {\r\n\t\tbase.baseMethod();\t\/\/ NG\r\n\t}\r\n\t\r\n}\r\n<\/pre>\n<p>Child\u30af\u30e9\u30b9\u306e\u4e2d\u3067Base\u30af\u30e9\u30b9\u306e\u5f15\u6570\u3092\u53d7\u3051\u53d6\u3063\u3066baseMethod()\u3092\u547c\u3073\u51fa\u305d\u3046\u3068\u3059\u308b\u3068\u3001&#8221;The method baseMethod() from the type Base is not visible&#8221;\u3068\u6012\u3089\u308c\u3066\u3057\u307e\u3046\u306e\u3067\u3059\u3002<br \/>\n<!--more--><br \/>\n\u5b9f\u306f\u3001Java\u306eprotected\u6307\u5b9a\u306e\u610f\u5473\u306f\u3001\u6b63\u78ba\u306b\u306f\u300c\u540c\u4e00\u30d1\u30c3\u30b1\u30fc\u30b8\u5185\u3068\u3001\u305d\u306e\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u305f\u30b5\u30d6\u30af\u30e9\u30b9\u5185\u304b\u3089\u3001<strong>\u305d\u306e\u30b5\u30d6\u30af\u30e9\u30b9\u3078\u306e\u53c2\u7167\u3092\u901a\u3057\u3066<\/strong>\u30a2\u30af\u30bb\u30b9\u3067\u304d\u308b\u300d\u3068\u306a\u308a\u307e\u3059\u3002\u3064\u307e\u308a\u3001Child\u30af\u30e9\u30b9\u306e\u4e2d\u304b\u3089\u547c\u3076\u3053\u3068\u304c\u3067\u304d\u308bbaseMethod()\u306f\u3001\u3042\u304f\u307e\u3067\u3082Child\u30af\u30e9\u30b9(\u307e\u305f\u306fChild\u30af\u30e9\u30b9\u306e\u30b5\u30d6\u30af\u30e9\u30b9)\u306ebaseMethod()\u3067\u3042\u308a\u3001Base\u30af\u30e9\u30b9\u306e\u305d\u308c\u3067\u306f\u306a\u3044\u306e\u3067\u3059\u3002<\/p>\n<p>\u4f8b\u3048\u3070\u3001\u6b21\u306e\u30b1\u30fc\u30b9\u3067\u306fbaseMethod()\u3092\u547c\u3076\u3053\u3068\u304c\u3067\u304d\u307e\u3059\u3002<\/p>\n<pre class=\"java\" name=\"code\">\r\npackage child;\r\n\r\nimport base.Base;\r\n\r\npublic class Child extends Base {\r\n\r\n\tpublic void childMethod(Child child) {\r\n\t\tthis.baseMethod();\t\/\/ OK\r\n\t\tchild.baseMethod();\t\/\/ OK\r\n\t}\r\n\t\r\n}\r\n<\/pre>\n<p>\u78ba\u304b\u306b\u3001\u89aa\u30af\u30e9\u30b9\u306eprotected\u30d5\u30a3\u30fc\u30eb\u30c9\u3092\u30b5\u30d6\u30af\u30e9\u30b9\u304b\u3089\u76f4\u63a5\u66f8\u304d\u63db\u3048\u3089\u308c\u308b\u3068\u554f\u984c\u304c\u3042\u308b\u304b\u3082\u3057\u308c\u307e\u305b\u3093\u304c\u3001\u305d\u3046\u3044\u3046\u30d5\u30a3\u30fc\u30eb\u30c9\u306fprivate\u306b\u3059\u308c\u3070\u3088\u3044(\u3068\u3044\u3046\u304b\u3001\u305d\u3046\u3059\u308b\u3079\u304d)\u3057\u3001\u30e1\u30bd\u30c3\u30c9\u547c\u3073\u51fa\u3057\u306f\u30dd\u30ea\u30e2\u30fc\u30d5\u30a3\u30ba\u30e0\u306b\u3059\u308b\u3053\u3068\u304c\u3067\u304d\u308b\u306e\u3067\u3001\u3053\u308c\u306f\u5c11\u3005\u4f59\u8a08\u306a\u5236\u9650\u3067\u3042\u308b\u3088\u3046\u306b\u601d\u3044\u307e\u3059\u3002<\/p>\n<p>\u3069\u3046\u3057\u3066\u3082Child\u30af\u30e9\u30b9\u306e\u4e2d\u304b\u3089Base\u30af\u30e9\u30b9\u306e\u53c2\u7167\u3092\u4f7f\u3063\u3066baseMethod()\u3092\u547c\u3073\u51fa\u3057\u305f\u3044\u5834\u5408\u306f\u3001<\/p>\n<pre class=\"java\" name=\"code\">\r\npackage base;\r\n\r\npublic class Base {\r\n\t\r\n\tprotected void baseMethod() {\r\n\t\tSystem.out.println(\"Base method.\");\r\n\t}\r\n\r\n\tprotected void invokeBaseMethod(Base base) {\r\n\t\tbase.baseMethod();\r\n\t}\r\n\t\r\n}\r\n<\/pre>\n<pre class=\"java\" name=\"code\">\r\npackage child;\r\n\r\nimport base.Base;\r\n\r\npublic class Child extends Base {\r\n\r\n\tpublic void childMethod(Base base) {\r\n\t\tinvokeBaseMethod(base);\r\n\t}\r\n\t\r\n}\r\n<\/pre>\n<p>\u3053\u3093\u306a\u3075\u3046\u306b\u3059\u308b\u3057\u304b\u624b\u306f\u306a\u3055\u305d\u3046\u3067\u3059\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Java\u306e\u30a2\u30af\u30bb\u30b9\u4fee\u98fe\u5b50protected\u3067\u5c11\u3057\u30cf\u30de\u3063\u305f\u306e\u3067\u3001\u8abf\u3079\u305f\u5185\u5bb9\u3092\u30e1\u30e2\u3057\u3066\u304a\u304d\u307e\u3059\u3002 \u901a\u5e38\u3001protected\u3068\u6307\u5b9a\u3055\u308c\u305f\u30d5\u30a3\u30fc\u30eb\u30c9\u3084\u30e1\u30bd\u30c3\u30c9\u306f\u300c\u540c\u4e00package\u5185\u3068\u3001\u305d\u306e\u30af\u30e9\u30b9\u3092\u7d99\u627f\u3057\u305f\u30b5\u30d6\u30af\u30e9\u30b9\u5185\u304b\u3089\u30a2\u30af\u30bb [&hellip;]<\/p>\n","protected":false},"author":4,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[17],"tags":[23,40,49],"class_list":["post-1934","post","type-post","status-publish","format-standard","hentry","category-tech","tag-java","tag-40","tag-49"],"_links":{"self":[{"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=\/wp\/v2\/posts\/1934","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=\/wp\/v2\/users\/4"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1934"}],"version-history":[{"count":8,"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=\/wp\/v2\/posts\/1934\/revisions"}],"predecessor-version":[{"id":1939,"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=\/wp\/v2\/posts\/1934\/revisions\/1939"}],"wp:attachment":[{"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1934"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1934"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.bitmeister.jp\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1934"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}