{"id":2042,"date":"2015-05-08T07:58:15","date_gmt":"2015-05-07T22:58:15","guid":{"rendered":"http:\/\/yucchi.jp\/blog\/?p=2042"},"modified":"2015-05-08T07:59:55","modified_gmt":"2015-05-07T22:59:55","slug":"java-util-concurrentmodificationexception-%e5%af%be%e5%87%a6%e6%b3%95","status":"publish","type":"post","link":"http:\/\/yucchi.jp\/blog\/?p=2042","title":{"rendered":"java.util.ConcurrentModificationException \u5bfe\u51e6\u6cd5"},"content":{"rendered":"<p>\u4eca\u65e5\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3082 J2SE5.0 \u6642\u4ee3\u306e\u53e4\u3044\u3082\u306e\u3067\u3059\u3002<\/p>\n<p>\u3057\u304b\u3057\u3001\u3042\u307e\u308a\u77e5\u3089\u308c\u3066\u3044\u306a\u3044\uff08\u76ee\u306b\u3059\u308b\u6a5f\u4f1a\u304c\u5c11\u306a\u3044\uff09\u3068\u601d\u308f\u308c\u308b\u306e\u3067\u30d6\u30ed\u30b0\u66f4\u65b0\u7528\u306e\u30cd\u30bf\u3068\u3057\u307e\u3057\u305f\u3002<\/p>\n<p>\u4eca\u56de\u306e\u554f\u984c\u306f\u4e8c\u3064\u306e\u30b9\u30ec\u30c3\u30c9\u304c\u4e26\u884c\u3057\u3066 List \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u3088\u304f\u3042\u308b\u554f\u984c\u3067\u3059\u3002<\/p>\n<p>\u3053\u3053\u3067\u601d\u3044\u51fa\u3057\u3066\u304f\u3060\u3055\u3044\u3002<\/p>\n<p>Java \u306e Iterator \u306f Fail-Fast \u306b\u8a2d\u8a08\u3055\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u3053\u308c\u306f\u30a4\u30c6\u30ec\u30fc\u30b7\u30e7\u30f3\u51e6\u7406\u958b\u59cb\u5f8c\u306b\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u306e\u5185\u5bb9\u304c\u5909\u66f4\u3055\u308c\u305f\u3053\u3068\u3092\u691c\u51fa\u3057\u305f\u3089\u76f4\u3061 java.util.ConcurrentModificationException \u3092\u30b9\u30ed\u30fc\u3057\u307e\u3059\u3002<\/p>\n<p>\u3053\u308c\u3092\u56de\u907f\u3059\u308b\u306b\u306f\u4e00\u756a\u624b\u3063\u53d6\u308a\u65e9\u3044\u306e\u306f synchronized \u30d6\u30ed\u30c3\u30af\u3092\u4f7f\u3063\u3066\u5236\u5fa1\u3059\u308b\u306e\u304c\u697d\u3067\u3059\u3002<\/p>\n<p>synchronizedList() \u3092\u4f7f\u3063\u3066\u308b\u304b\u3089\u5927\u4e08\u592b\u3060\u3068\u601d\u3063\u3066\u3044\u308b\u4eba\u306f\u6ce3\u3044\u3066\u304f\u3060\u3055\u3044\u3002\uff08\u30f2\u30d2<\/p>\n<p>Iterator \u306a\u3081\u305f\u3089\u3042\u304b\u3093\u305c\u3088\uff01<\/p>\n<p>\u3055\u3066\u3001\u3044\u3063\u305f\u3044\u4f55\u3092\u8a00\u3044\u305f\u3044\u306e\u304b\u826f\u304f\u89e3\u3089\u306a\u3044\u3068\u601d\u3046\u306e\u3067\u7c21\u6f54\u306b\u307e\u3068\u3081\u3066\u3044\u306a\u3044\u30c0\u30e9\u30c0\u30e9\u3068\u3057\u305f\u30b5\u30f3\u30d7\u30eb\u30b3\u30fc\u30c9\u3092\u3054\u89a7\u304f\u3060\u3055\u3044\u3002<\/p>\n<p><pre title=\"GirlFriends_1.java\">\r\npackage jp.yucchi.girlfriends_cme;\r\n\r\nimport java.util.List;\r\nimport java.util.concurrent.TimeUnit;\r\nimport java.util.logging.Level;\r\nimport java.util.logging.Logger;\r\n\r\n\/**\r\n *\r\n * @author Yucchi\r\n *\/\r\nclass GirlFriends_1 {\r\n\r\n    private final List<String> girlFriends;\r\n\r\n    GirlFriends_1(List<String> girlFriends) {\r\n        this.girlFriends = girlFriends;\r\n    }\r\n\r\n    List<String> updateGirlFriend() {\r\n        Thread.currentThread().setName(\" Girls_1\");\r\n        girlFriends.add(\"\u5317\u5ddd\u666f\u5b50\");\r\n        girlFriends.add(\"\u6850\u8c37\u7f8e\u73b2\");\r\n        girlFriends.add(\"\u65b0\u57a3\u7d50\u8863\");\r\n        girlFriends.add(\"\u525b\u529b\u5f69\u82bd\");\r\n\r\n        girlFriends.forEach(e -> {\r\n            System.out.println(e + Thread.currentThread().getName());\r\n            try {\r\n                TimeUnit.MILLISECONDS.sleep(1_000);\r\n            } catch (InterruptedException ex) {\r\n                Logger.getLogger(GirlFriends_1.class.getName()).log(Level.SEVERE, null, ex);\r\n            }\r\n        });\r\n\r\n        return girlFriends;\r\n\r\n    }\r\n}\r\n\r\n\r\n<\/pre>\n<pre title=\"GirlFriends_2.java\">\r\npackage jp.yucchi.girlfriends_cme;\r\n\r\nimport java.util.List;\r\nimport java.util.concurrent.TimeUnit;\r\nimport java.util.logging.Level;\r\nimport java.util.logging.Logger;\r\n\r\n\/**\r\n *\r\n * @author Yucchi\r\n *\/\r\nclass GirlFriends_2 {\r\n\r\n    private final List<String> girlFriends;\r\n\r\n    GirlFriends_2(List<String> girlFriends) {\r\n        this.girlFriends = girlFriends;\r\n    }\r\n\r\n    List<String> updateGirlFriend() {\r\n        Thread.currentThread().setName(\" Girls_2\");\r\n        try {\r\n            TimeUnit.MILLISECONDS.sleep(1_000);\r\n        } catch (InterruptedException ex) {\r\n            Logger.getLogger(GirlFriends_1.class.getName()).log(Level.SEVERE, null, ex);\r\n        }\r\n        girlFriends.remove(\"\u5317\u5ddd\u666f\u5b50\");\r\n        girlFriends.remove(\"\u6850\u8c37\u7f8e\u73b2\");\r\n        girlFriends.remove(\"\u65b0\u57a3\u7d50\u8863\");\r\n        girlFriends.remove(\"\u525b\u529b\u5f69\u82bd\");\r\n\r\n        girlFriends.forEach(e -> {\r\n            System.out.println(e + Thread.currentThread().getName());\r\n        });\r\n\r\n        return girlFriends;\r\n    }\r\n\r\n}\r\n\r\n\r\n<\/pre>\n<pre title=\"GirlFriends_CME.java\">\r\npackage jp.yucchi.girlfriends_cme;\r\n\r\nimport java.util.ArrayList;\r\nimport java.util.List;\r\nimport java.util.concurrent.CompletableFuture;\r\nimport java.util.concurrent.ExecutionException;\r\nimport java.util.concurrent.TimeUnit;\r\nimport java.util.logging.Level;\r\nimport java.util.logging.Logger;\r\n\r\n\/**\r\n *\r\n * @author Yucchi\r\n *\/\r\npublic class GirlFriends_CME {\r\n\r\n    public static void main(String[] args) {\r\n\r\n        List<String> girlFriends = new ArrayList<>();\r\n\r\n        girlFriends.add(\"\u5800\u5317\u771f\u5e0c\");\r\n\r\n        GirlFriends_1 girlFriend_1 = new GirlFriends_1(girlFriends);\r\n        GirlFriends_2 girlFriend_2 = new GirlFriends_2(girlFriends);\r\n\r\n        CompletableFuture<List<String>> girls_1 = CompletableFuture.supplyAsync(() -> girlFriend_1.updateGirlFriend());\r\n        CompletableFuture<List<String>> girls_2 = CompletableFuture.supplyAsync(() -> girlFriend_2.updateGirlFriend());\r\n\r\n        CompletableFuture<Void> allTask = CompletableFuture.allOf(girls_1, girls_2);\r\n        allTask.join();\r\n\r\n        girlFriends.add(\"\u7dbe\u702c\u306f\u308b\u304b\");\r\n\r\n        if (allTask.isDone()) {\r\n            try {\r\n                System.out.println(\"GirlFriend_1 List\");\r\n                girls_1.get().forEach(System.out::println);\r\n                System.out.println(\"GirlFriend_2 List\");\r\n                girls_2.get().forEach(System.out::println);\r\n            } catch (InterruptedException | ExecutionException ex) {\r\n                Logger.getLogger(GirlFriends_CME.class.getName()).log(Level.SEVERE, null, ex);\r\n            }\r\n        }\r\n\r\n        try {\r\n            TimeUnit.MILLISECONDS.sleep(1_000);\r\n            girlFriends.add(\"\u65b0\u57a3\u7d50\u8863\");\r\n            girlFriends.add(\"\u525b\u529b\u5f69\u82bd\");\r\n        } catch (InterruptedException ex) {\r\n            Logger.getLogger(GirlFriends_1.class.getName()).log(Level.SEVERE, null, ex);\r\n        }\r\n\r\n        System.out.println(\"GirlFriend List\");\r\n        girlFriends.forEach(System.out::println);\r\n    }\r\n\r\n}\r\n\r\n\r\n<\/pre>\n<\/p>\n<p>\u3053\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u7d50\u679c\u306f\u6b21\u306e\u3088\u3046\u306a\u5b9f\u884c\u6642\u30a8\u30e9\u30fc\u304c\u3067\u307e\u3059\u3002<\/p>\n<p>\u5800\u5317\u771f\u5e0c Girls_1<br \/>\u5317\u5ddd\u666f\u5b50 Girls_1<br \/>\u5800\u5317\u771f\u5e0c Girls_2<br \/>Exception in thread &#8220;main&#8221; java.util.concurrent.CompletionException: java.util.ConcurrentModificationException<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:273)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:280)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1584)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1574)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1689)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)<br \/>Caused by: java.util.ConcurrentModificationException<br \/>&nbsp;&nbsp;&nbsp; at java.util.ArrayList.forEach(ArrayList.java:1252)<br \/>&nbsp;&nbsp;&nbsp; at jp.yucchi.girlfriends_cme.GirlFriends_1.updateGirlFriend(GirlFriends_1.java:27)<br \/>&nbsp;&nbsp;&nbsp; at jp.yucchi.girlfriends_cme.GirlFriends_CME.lambda$main$0(GirlFriends_CME.java:26)<br \/>&nbsp;&nbsp;&nbsp; at jp.yucchi.girlfriends_cme.GirlFriends_CME$$Lambda$1\/424058530.get(Unknown Source)<br \/>&nbsp;&nbsp;&nbsp; at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1582)<br \/>&nbsp;&nbsp;&nbsp; &#8230; 5 more<br \/>Java Result: 1<\/p>\n<p>\u3053\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u306f\u3001GirlFriends_1 \u30b9\u30ec\u30c3\u30c9\u3067\u8981\u7d20\u3092\u8ffd\u52a0\u3057\u3001\u30a4\u30c6\u30ec\u30fc\u30b7\u30e7\u30f3\u51e6\u7406\u3092\u8981\u7d20\u3092\u4e00\u3064\u51fa\u529b\u3055\u305b\u308b\u3054\u3068\u306b\u4e00\u79d2\u9593\u30b9\u30ec\u30c3\u30c9\u3092\u30b9\u30ea\u30fc\u30d7\u3055\u305b\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>GirlFriends_2 \u30b9\u30ec\u30c3\u30c9\u3067\u306f\u3001\u8981\u7d20\u306e\u524a\u9664\u51e6\u7406\u306e\u958b\u59cb\u3092\u4e00\u79d2\u9045\u3089\u305b\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>GirlFriends_1 \u30b9\u30ec\u30c3\u30c9\u306e\u30a4\u30c6\u30ec\u30fc\u30b7\u30e7\u30f3\u51e6\u7406\u4e2d\u306b&nbsp; GirlFriends_2 \u30b9\u30ec\u30c3\u30c9 \u306b\u3088\u3063\u3066 List \u306e\u5185\u5bb9\u304c\u5909\u66f4\u3055\u308c\u3066\u3057\u307e\u3044\u307e\u3059\u3002<\/p>\n<p>\u4e8c\u3064\u306e\u30b9\u30ec\u30c3\u30c9\u3067\u4e00\u3064\u306e List \u306b\u4f55\u3082\u8003\u3048\u305a\u306b\u4e26\u884c\u51e6\u7406\u3057\u3066\u3044\u308b\u7121\u6b8b\u306a\u7d50\u679c\u304c\u60b2\u3057\u3044\u3067\u3059\u306d\u3002<\/p>\n<p>\u3067\u306f\u3001\u5b89\u5168\u306b\u4e26\u884c\u51e6\u7406\u3059\u308b\u305f\u3081\u306b synchronized \u30d6\u30ed\u30c3\u30af \u3092\u4f7f\u3063\u3066\u7d42\u308f\u308a\u3067\u306f\u3064\u307e\u3089\u306a\u3044\u306e\u3067\u3082\u3046\u4e00\u3064\u306e\u89e3\u6c7a\u65b9\u6cd5\u3092\u7d39\u4ecb\u3057\u307e\u3059\u3002<\/p>\n<p>\u3053\u308c\u3092\u4f7f\u3046\u6a5f\u4f1a\u3063\u3066\u6ec5\u591a\u306b\u306a\u3044\u3067\u3057\u3087\u3046\u3051\u3069 java.util.concurrent.CopyOnWriteArrayList&lt;E&gt; \u3063\u3066\u306e\u304c\u3042\u308a\u307e\u3059\u3002<\/p>\n<p>API \u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306b\u306f\u6b21\u306e\u3088\u3046\u306b\u66f8\u304b\u308c\u3066\u3044\u307e\u3059\u3002<\/p>\n<p><font color=\"#666666\">\u57fa\u306b\u306a\u308b\u914d\u5217\u306e\u65b0\u3057\u3044\u30b3\u30d4\u30fc\u3092\u4f5c\u6210\u3059\u308b\u3053\u3068\u306b\u3088\u308a\u3001\u3059\u3079\u3066\u306e\u63a8\u79fb\u7684\u64cd\u4f5c(add\u3001set\u306a\u3069)\u304c\u5b9f\u88c5\u3055\u308c\u308bArrayList\u306e\u30b9\u30ec\u30c3\u30c9\u30fb\u30bb\u30fc\u30d5\u306a\u5909\u6570\u3067\u3059\u3002<br \/>\u901a\u5e38\u3001\u3053\u308c\u306f\u975e\u5e38\u306b\u52b9\u7387\u304c\u60aa\u3044\u306e\u3067\u3059\u304c\u3001\u30c8\u30e9\u30d0\u30fc\u30b5\u30eb\u64cd\u4f5c\u304c\u5909\u66f4\u3092\u6570\u306e\u70b9\u3067\u5927\u5e45\u306b\u4e0a\u56de\u308b\u5834\u5408\u306b\u306f\u3001\u4ee3\u66ff\u624b\u6bb5\u3088\u308a\u3082\u52b9\u7387\u304c\u826f\u3044\u5834\u5408\u304c\u3042\u308a\u307e\u3059\u3002 <br \/>\u307e\u305f\u3001\u3053\u308c\u306f\u3001\u30c8\u30e9\u30d0\u30fc\u30b5\u30eb\u3092\u540c\u671f\u3067\u304d\u306a\u3044\u5834\u5408\u3084\u3001\u540c\u671f\u3059\u308b\u3053\u3068\u3092\u671b\u307e\u306a\u3044\u304c\u3001\u4e26\u884c\u30b9\u30ec\u30c3\u30c9\u9593\u306e\u5e72\u6e09\u3092\u6392\u9664\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b\u5834\u5408\u306b\u6709\u7528\u3067\u3059\u3002 <br \/>\u300c\u30b9\u30ca\u30c3\u30d7\u30b7\u30e7\u30c3\u30c8\u300d\u30b9\u30bf\u30a4\u30eb\u306e\u30a4\u30c6\u30ec\u30fc\u30bf\u30fb\u30e1\u30bd\u30c3\u30c9\u306f\u3001\u30a4\u30c6\u30ec\u30fc\u30bf\u306e\u4f5c\u6210\u6642\u70b9\u3067\u306e\u914d\u5217\u72b6\u614b\u3078\u306e\u53c2\u7167\u3092\u4f7f\u7528\u3057\u307e\u3059\u3002 <br \/>\u3053\u306e\u914d\u5217\u304c\u30a4\u30c6\u30ec\u30fc\u30bf\u306e\u6709\u52b9\u671f\u9593\u4e2d\u306b\u5909\u66f4\u3055\u308c\u308b\u3053\u3068\u306f\u6c7a\u3057\u3066\u306a\u3044\u305f\u3081\u3001\u5e72\u6e09\u306f\u4e0d\u53ef\u80fd\u3067\u3042\u308a\u3001\u30a4\u30c6\u30ec\u30fc\u30bf\u306fConcurrentModificationException\u3092\u30b9\u30ed\u30fc\u3057\u306a\u3044\u3053\u3068\u304c\u4fdd\u8a3c\u3055\u308c\u307e\u3059\u3002 <br \/>\u30a4\u30c6\u30ec\u30fc\u30bf\u306f\u3001\u30a4\u30c6\u30ec\u30fc\u30bf\u306e\u4f5c\u6210\u4ee5\u964d\u306e\u30ea\u30b9\u30c8\u3078\u306e\u8ffd\u52a0\u3001\u524a\u9664\u3001\u307e\u305f\u306f\u5909\u66f4\u3092\u53cd\u6620\u3057\u307e\u305b\u3093\u3002<br \/>\u30a4\u30c6\u30ec\u30fc\u30bf\u81ea\u4f53\u306b\u5bfe\u3059\u308b\u8981\u7d20\u5909\u66f4\u64cd\u4f5c(remove\u3001set\u304a\u3088\u3073add)\u306f\u30b5\u30dd\u30fc\u30c8\u3055\u308c\u307e\u305b\u3093\u3002<br \/>\u3053\u308c\u3089\u306e\u30e1\u30bd\u30c3\u30c9\u306f\u3001UnsupportedOperationException\u3092\u30b9\u30ed\u30fc\u3057\u307e\u3059\u3002 <br \/>null\u3092\u542b\u3080\u3059\u3079\u3066\u306e\u8981\u7d20\u304c\u8a31\u53ef\u3055\u308c\u307e\u3059\u3002 <br \/>\u30e1\u30e2\u30ea\u30fc\u6574\u5408\u6027\u52b9\u679c: \u307b\u304b\u306e\u4e26\u884c\u51e6\u7406\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u3068\u540c\u69d8\u3001\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u3092CopyOnWriteArrayList\u306b\u914d\u7f6e\u3059\u308b\u524d\u306e\u30b9\u30ec\u30c3\u30c9\u5185\u306e\u30a2\u30af\u30b7\u30e7\u30f3\u306f\u3001<br \/>\u5225\u306e\u30b9\u30ec\u30c3\u30c9\u3067\u306e\u305d\u306e\u8981\u7d20\u3078\u306e\u30a2\u30af\u30bb\u30b9\u307e\u305f\u306fCopyOnWriteArrayList\u304b\u3089\u306e\u524a\u9664\u306b\u7d9a\u304f\u30a2\u30af\u30b7\u30e7\u30f3\u3088\u308a\u3082\u524d\u306b\u767a\u751f\u3057\u307e\u3059\u3002<\/font><\/p>\n<p>\u4eca\u56de\u306e\u30b1\u30fc\u30b9\u3067\u306f\u304a\u624b\u8efd\u306b\u4f7f\u3048\u305d\u3046\u3067\u3059\u306d\u3002<\/p>\n<p>\u305d\u3046\u8a00\u3046\u3053\u3068\u3067\u307e\u305f\u30c0\u30e9\u30c0\u30e9\u3068\u30b3\u30fc\u30c9\u3092\u3054\u89a7\u304f\u3060\u3055\u3044\u3002\u3068\u3001\u601d\u3063\u305f\u3051\u3069 List \u3092 CopyOnWriteArrayList \u306b\u5909\u66f4\u3059\u308b\u3060\u3051\u306a\u306e\u3067\u3084\u3081\u3066\u304a\u304d\u307e\u3059\u3002<\/p>\n<p>\u3044\u3061\u304a\u3046\u3001 GitHub \u306b\u30a2\u30c3\u30d7\u3057\u3066\u304a\u304d\u307e\u3059\u306e\u3067\u898b\u305f\u3044\u65b9\u306f\u3069\u3046\u305e\u3002<\/p>\n<p><a title=\"https:\/\/github.com\/Yucchi-1995\/GirlFriends\" href=\"https:\/\/github.com\/Yucchi-1995\/GirlFriends\">https:\/\/github.com\/Yucchi-1995\/GirlFriends<\/a><\/p>\n<p>\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u7d50\u679c\u306f\u6b21\u306e\u3088\u3046\u306b\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>\u5800\u5317\u771f\u5e0c Girls_1<br \/>\u5317\u5ddd\u666f\u5b50 Girls_1<br \/>\u5800\u5317\u771f\u5e0c Girls_2<br \/>\u6850\u8c37\u7f8e\u73b2 Girls_1<br \/>\u65b0\u57a3\u7d50\u8863 Girls_1<br \/>\u525b\u529b\u5f69\u82bd Girls_1<br \/>GirlFriend_1 List<br \/>\u5800\u5317\u771f\u5e0c<br \/>\u7dbe\u702c\u306f\u308b\u304b<br \/>GirlFriend_2 List<br \/>\u5800\u5317\u771f\u5e0c<br \/>\u7dbe\u702c\u306f\u308b\u304b<br \/>GirlFriend List<br \/>\u5800\u5317\u771f\u5e0c<br \/>\u7dbe\u702c\u306f\u308b\u304b<br \/>\u65b0\u57a3\u7d50\u8863<br \/>\u525b\u529b\u5f69\u82bd<\/p>\n<p>java.util.ConcurrentModificationException \u304c\u6295\u3052\u3089\u308c\u308b\u3053\u3068\u306a\u304f\u4e26\u884c\u51e6\u7406\u304c\u5b8c\u4e86\u3057\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>\u3068\u3066\u3082\u7c21\u5358\u3067\u3059\u3002<\/p>\n<p>API \u30c9\u30ad\u30e5\u30e1\u30f3\u30c8\u306b\u3082\u66f8\u3044\u3066\u3042\u308a\u307e\u3059\u304c CopyOnWriteArrayList \u306f\u30a4\u30c6\u30ec\u30fc\u30bf\u306e\u4f5c\u6210\u6642\u70b9\u3067\u306e\u914d\u5217\u72b6\u614b\u3078\u306e\u53c2\u7167\u3092\u4f7f\u7528\u3057\u3001<\/p>\n<p>\u3053\u306e\u914d\u5217\u304c\u30a4\u30c6\u30ec\u30fc\u30bf\u306e\u6709\u52b9\u671f\u9593\u4e2d\u306b\u5909\u66f4\u3055\u308c\u308b\u3053\u3068\u306f\u6c7a\u3057\u3066\u306a\u3044\u3068\u8a00\u3044\u5207\u3063\u3066\u3044\u308b\u3068\u304a\u308a\u3001<\/p>\n<p>\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u5b9f\u884c\u7d50\u679c\u3088\u308a Girls_1 \u30b9\u30ec\u30c3\u30c9\u3001Girls_2 \u30b9\u30ec\u30c3\u30c9\u306e\u30a4\u30c6\u30ec\u30fc\u30b7\u30e7\u30f3\u51e6\u7406\u51fa\u529b\u304c\u305d\u306e\u3068\u304a\u308a\u306b\u51fa\u529b\u3055\u308c\u3066\u3044\u308b\u306e\u304c\u78ba\u8a8d\u3067\u304d\u307e\u3059\u3002<\/p>\n<p>\u5800\u5317\u771f\u5e0c Girls_1<br \/>\u5317\u5ddd\u666f\u5b50 Girls_1<br \/>\u5800\u5317\u771f\u5e0c Girls_2<br \/>\u6850\u8c37\u7f8e\u73b2 Girls_1<br \/>\u65b0\u57a3\u7d50\u8863 Girls_1<br \/>\u525b\u529b\u5f69\u82bd Girls_1<\/p>\n<p>\u305d\u3057\u3066\u3001Girls_1 \u30b9\u30ec\u30c3\u30c9\u3001Girls_2 \u30b9\u30ec\u30c3\u30c9\u304b\u3089\u8fd4\u3055\u308c\u308b List \u306e\u8981\u7d20\u306f\u300c\u5800\u5317\u771f\u5e0c\u300d\u306e\u4e00\u3064\u3068\u306a\u308a\u307e\u3059\u3002<\/p>\n<p>GirlFriend_1 List\u3001GirlFriend_2 List \u306e\u51fa\u529b\u304c<\/p>\n<p>GirlFriend_1 List<br \/>\u5800\u5317\u771f\u5e0c<br \/>\u7dbe\u702c\u306f\u308b\u304b<br \/>GirlFriend_2 List<br \/>\u5800\u5317\u771f\u5e0c<br \/>\u7dbe\u702c\u306f\u308b\u304b<\/p>\n<p>\u3068\u306a\u3063\u3066\u3044\u308b\u306e\u306f main \u30b9\u30ec\u30c3\u30c9\u306b\u623b\u3063\u3066\u304b\u3089\u300c\u7dbe\u702c\u306f\u308b\u304b\u300d\u304c\u8ffd\u52a0\u3055\u308c\u51fa\u529b\u3055\u308c\u3066\u3044\u308b\u304b\u3089\u3067\u3059\u3002<\/p>\n<p>\u305d\u3057\u3066\u3001\u6700\u5f8c\u306b\u300c\u65b0\u57a3\u7d50\u8863\u300d\u3068\u300c\u525b\u529b\u5f69\u82bd\u300d\u3092\u8ffd\u52a0\u3057\u3066 List \u3092\u8868\u793a\u3055\u305b\u3066\u3044\u307e\u3059\u3002<\/p>\n<p>CopyOnWriteArrayList \u3063\u3066\u672c\u5f53\u306b\u512a\u308c\u3082\u306e\u3067\u3059\u306d\uff01<\/p>\n<p>\u3069\u3046\u3067\u3082\u3044\u3044\u3053\u3068\u3067\u3059\u304c\u3001\u3053\u306e\u30d7\u30ed\u30b0\u30e9\u30e0\u306e\u6b20\u9665\u306f\u300c\u5317\u5ddd\u666f\u5b50\u300d\u3092\u524a\u9664\u3057\u3066\u3001\u3042\u3068\u3067\u518d\u3073 List \u306b\u8ffd\u52a0\u3059\u308b\u4e88\u5b9a\u3060\u3063\u305f\u306e\u3092\u3059\u3063\u304b\u308a\u5fd8\u308c\u3066\u3057\u307e\u3063\u305f\u3053\u3068\u3067\u3059\u3002(^_^;)<\/p>\n<div id=\"scid:0767317B-992E-4b12-91E0-4F059A8CECA8:53d41052-402e-461e-bab5-4d09d253e9e6\" class=\"wlWriterEditableSmartContent\" style=\"float: none; padding-bottom: 0px; padding-top: 0px; padding-left: 0px; margin: 0px; display: inline; padding-right: 0px\">Hatena \u30bf\u30b0: <a href=\"http:\/\/b.hatena.ne.jp\/t\/Java\" rel=\"tag\">Java<\/a><\/div>\n<div class='wp_social_bookmarking_light'>\n            <div class=\"wsbl_hatena\"><a href='\/\/b.hatena.ne.jp\/add?mode=confirm&url=http%3A%2F%2Fyucchi.jp%2Fblog%2F%3Fp%3D2042&title=java.util.ConcurrentModificationException%20%E5%AF%BE%E5%87%A6%E6%B3%95' title='\u3053\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3092\u306f\u3066\u306a\u30d6\u30c3\u30af\u30de\u30fc\u30af\u306b\u8ffd\u52a0' rel=nofollow class='wp_social_bookmarking_light_a' target=_blank><img 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class='wp_social_bookmarking_light_img' \/><\/a><\/div>\n            <div class=\"wsbl_google_plus_one\"><g:plusone size=\"medium\" annotation=\"none\" href=\"http:\/\/yucchi.jp\/blog\/?p=2042\" ><\/g:plusone><\/div>\n            <div class=\"wsbl_twitter\"><a href=\"https:\/\/twitter.com\/share\" class=\"twitter-share-button\" data-url=\"http:\/\/yucchi.jp\/blog\/?p=2042\" data-text=\"java.util.ConcurrentModificationException \u5bfe\u51e6\u6cd5\" data-lang=\"ja\">Tweet<\/a><\/div>\n    <\/div>\n<br class='wp_social_bookmarking_light_clear' \/>\n","protected":false},"excerpt":{"rendered":"<p>\u4eca\u65e5\u306e\u30a8\u30f3\u30c8\u30ea\u30fc\u3082 J2SE5.0 \u6642\u4ee3\u306e\u53e4\u3044\u3082\u306e\u3067\u3059\u3002 \u3057\u304b\u3057\u3001\u3042\u307e\u308a\u77e5\u3089\u308c\u3066\u3044\u306a\u3044\uff08\u76ee\u306b\u3059\u308b\u6a5f\u4f1a\u304c\u5c11\u306a\u3044\uff09\u3068\u601d\u308f\u308c\u308b\u306e\u3067\u30d6\u30ed\u30b0\u66f4\u65b0\u7528\u306e\u30cd\u30bf\u3068\u3057\u307e\u3057\u305f\u3002 \u4eca\u56de\u306e\u554f\u984c\u306f\u4e8c\u3064\u306e\u30b9\u30ec\u30c3\u30c9\u304c\u4e26\u884c\u3057\u3066 List \u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u306b\u30a2\u30af\u30bb\u30b9\u3059\u308b\u3088\u304f\u3042\u308b\u554f\u984c\u3067\u3059\u3002 \u3053\u3053\u3067\u601d\u3044\u51fa\u3057\u3066\u304f\u3060\u3055\u3044\u3002 Java \u306e Iterator \u306f Fail-Fast \u306b\u8a2d\u8a08\u3055\u308c\u3066\u3044\u307e\u3059\u3002 \u3053\u308c\u306f\u30a4\u30c6\u30ec\u30fc\u30b7\u30e7\u30f3\u51e6\u7406\u958b\u59cb\u5f8c\u306b\u30b3\u30ec\u30af\u30b7\u30e7\u30f3\u306e\u5185\u5bb9\u304c\u5909\u66f4\u3055\u308c\u305f\u3053\u3068\u3092\u691c\u51fa\u3057\u305f\u3089\u76f4\u3061 java.util.ConcurrentModificationException \u3092\u30b9\u30ed\u30fc\u3057\u307e\u3059\u3002 \u3053\u308c\u3092\u56de\u907f\u3059\u308b\u306b\u306f\u4e00\u756a\u624b\u3063\u53d6\u308a\u65e9\u3044\u306e\u306f synchroni\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[17],"class_list":["post-2042","post","type-post","status-publish","format-standard","hentry","category-java","tag-java"],"_links":{"self":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2042","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2042"}],"version-history":[{"count":3,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2042\/revisions"}],"predecessor-version":[{"id":2045,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=\/wp\/v2\/posts\/2042\/revisions\/2045"}],"wp:attachment":[{"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2042"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2042"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/yucchi.jp\/blog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2042"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}