{"id":898,"date":"2021-03-05T18:37:00","date_gmt":"2021-03-05T09:37:00","guid":{"rendered":"http:\/\/www.opentone.co.jp\/ot-lab\/?p=898"},"modified":"2025-05-12T10:06:20","modified_gmt":"2025-05-12T01:06:20","slug":"java1-4","status":"publish","type":"post","link":"https:\/\/www.opentone.co.jp\/ot-lab\/all\/web-system\/java1-4","title":{"rendered":"Java1.4\u3068\u306e\u4ed8\u304d\u5408\u3044\u65b9"},"content":{"rendered":"\n<p>\u3053\u3093\u306b\u3061\u306f\u3002kk\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u73fe\u5728\u95a2\u308f\u3063\u3066\u3044\u308b\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306f\u3001Java\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u304c1.4\u3068\u306a\u3063\u3066\u3044\u307e\u3059\u3002<br>\u305d\u306e\u305f\u3081\u3001\u666e\u6bb5\u5f53\u7136\u306e\u3088\u3046\u306b\u4f7f\u3063\u3066\u3044\u308b\u6a5f\u80fd\u304c\u4f7f\u3048\u306a\u304b\u3063\u305f\u308a\u3057\u307e\u3059\u3002<br>\u4eca\u56de\u306f\u3001Java1.4\u306b\u7121\u304f1.5\u4ee5\u4e0a\u3067\u8ffd\u52a0\u3055\u308c\u305f\u6a5f\u80fd\u306b\u3064\u3044\u3066\u3001\u3044\u304f\u3064\u304b\u5fa9\u7fd2\u3082\u517c\u306d\u3066\u518d\u78ba\u8a8d\u3059\u308b\u306e\u3068\u30011.4\u3067\u5b9f\u88c5\u3057\u3066\u3044\u304f\u4e0a\u3067\u306e\u6ce8\u610f\u70b9\u3092\u66f8\u3044\u3066\u307f\u305f\u3044\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">\u30b8\u30a7\u30cd\u30ea\u30af\u30b9<\/h3>\n\n\n\n<p>\u578b\u3092\u6307\u5b9a\u3059\u308b\u30a2\u30ec\u3067\u3059\u3002<br>List\u3084Map\u3067\u3088\u304f\u898b\u304b\u3051\u307e\u3059\u306d\u3002\u30af\u30e9\u30b9\u306b\u4f7f\u3046\u3068\u6c4e\u7528\u7684\u306a\u7269\u3092\u4f5c\u6210\u51fa\u6765\u305f\u308a\u3057\u307e\u3059\u304c\u3001\u79c1\u81ea\u8eab\u306f\u3042\u307e\u308a\u305d\u3046\u3044\u3046\u5b9f\u88c5\u7d4c\u9a13\u304c\u3042\u308a\u307e\u305b\u3093\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    List&lt;String&gt; strList = new ArrayList&lt;String&gt;();\n    strList.add(\"test\");\n    \n    String getStr = strList.get(0);\n[\/sourcecode]<\/pre>\n\n\n\n<p>\u3010\u30e1\u30ea\u30c3\u30c8\u30681.4\u306e\u6ce8\u610f\u70b9\u3011<br>\u30b8\u30a7\u30cd\u30ea\u30af\u30b9\u3092\u4f7f\u308f\u305a\u306b\u66f8\u304f\u3068\u3069\u3046\u306a\u308b\u3067\u3057\u3087\u3046\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    List strList = new ArrayList();\n    strList.add(\"test\");\n    \n    String getStr = (String) strList.get(0);\n[\/sourcecode]<\/pre>\n\n\n\n<p>\u3053\u306e\u69d8\u306a\u5f62\u306b\u306a\u308a\u307e\u3059\u3002<br>get \u30e1\u30bd\u30c3\u30c9\u306f\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u578b\u3067\u8fd4\u5374\u3057\u307e\u3059\u306e\u3067\u3001\u6271\u3046\u306b\u306f\u9069\u5b9c\u30ad\u30e3\u30b9\u30c8\u304c\u5fc5\u8981\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u3067\u306f\u3001\u3053\u3046\u3057\u305f\u3089\uff1f<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    List strList = new ArrayList();\n    strList.add(123);\n\n    String getStr = (String) strList.get(0);\n[\/sourcecode]<\/pre>\n\n\n\n<p>\u6587\u6cd5\u4e0a\u306f\u9593\u9055\u3063\u3066\u3044\u306a\u3044\u306e\u3067\u30b3\u30f3\u30d1\u30a4\u30eb\u306f\u901a\u308a\u307e\u3059\u304c\u3001int\u578b\u3092String\u578b\u306b\u5909\u63db\u3057\u3088\u3046\u3068\u3057\u3066\u3044\u308b\u306e\u3067\u3001\u5b9f\u884c\u6642\u306b ClassCastException \u304c\u767a\u751f\u3057\u307e\u3059\u3002<br>\u30b8\u30a7\u30cd\u30ea\u30af\u30b9\u3092\u4f7f\u3046\u4e8b\u3067\u3001\u6307\u5b9a\u3057\u305f\u578b\u3067\u3057\u304b\u6271\u3048\u306a\u3044\u3088\u3046\u306b\u306a\u308b\u305f\u3081\u3001\u3053\u306e\u69d8\u306a\u4e8b\u614b\u306f\u30b3\u30f3\u30d1\u30a4\u30eb\u6642\u306b\u56de\u907f\u51fa\u6765\u307e\u3059\u3002<br>\u526f\u6b21\u7684\u306a\u52b9\u679c\u3067\u3059\u304c\u3001\u3044\u3061\u3044\u3061\u30ad\u30e3\u30b9\u30c8\u3092\u3057\u306a\u304f\u3066\u826f\u3044\u306e\u3067\u3001\u898b\u305f\u76ee\u304c\u30b9\u30c3\u30ad\u30ea\u3057\u3066\u53ef\u8aad\u6027\u304c\u5411\u4e0a\u3057\u307e\u3059\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">for-each\u6587\uff08\u62e1\u5f35for\u6587\uff09<\/h3>\n\n\n\n<p>\u3053\u3061\u3089\u3082List\u3092\u51e6\u7406\u3059\u308b\u5834\u9762\u3067\u3088\u304f\u898b\u304b\u3051\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    List&lt;String&gt; strList = new ArrayList&lt;String&gt;();\n    strList.add(\"test\");\n    strList.add(\"test2\");\n\n    for (String str : strList) {\n        System.out.println(str);\n    }\n[\/sourcecode]<\/pre>\n\n\n\n<p>List\u306b\u9650\u3089\u305a\u3001\u8907\u6570\u306e\u8981\u7d20\u3092\u6301\u3064\u3082\u306e\uff08\u914d\u5217\u3068\u304b\uff09\u306b\u5bfe\u3057\u3001\u8981\u7d20\u30921\u3064\u305a\u3064\u53d6\u308a\u51fa\u3057\u3066\u7e70\u308a\u8fd4\u3057\u51e6\u7406\u3092\u884c\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<p>\u30101.4\u3067\u5b9f\u88c5\u3059\u308b\u3068\u2026\u3011<br>\u591a\u304f\u306e\u5834\u5408\u3053\u3093\u306a\u5f62\u306b\u306a\u308b\u3068\u601d\u3044\u307e\u3059\u3002<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    List strList = new ArrayList();\n    strList.add(\"test\");\n    strList.add(\"test2\");\n\n    for (int i = 0; i &lt; strList.size(); i++) {\n        System.out.println(strList.get(i));\n    }\n[\/sourcecode]<\/pre>\n\n\n\n<p>for\u6587\u306b\u5bfe\u3057\u3001\u521d\u671f\u5024\uff1b\u8a55\u4fa1\u5f0f\uff1b\u5897\u5206\u5024 \u3092\u4e0e\u3048\u3001\u8a55\u4fa1\u5f0f\u304cTrue\u306e\u9593\u7e70\u308a\u8fd4\u3057\u307e\u3059\u3002<br>\u8981\u7d20\u3092\u53d6\u308a\u51fa\u3059\u51e6\u7406\u306f\u5225\u9014\u66f8\u304f\u5fc5\u8981\u304c\u3042\u308b\u306e\u3067\u3001\u3061\u3087\u3063\u3068\u9762\u5012\u3067\u3059\u306d\u3002<br>\u307e\u305f\u3001IndexOutOfBoundsException \u304c\u767a\u751f\u3059\u308b\u53ef\u80fd\u6027\u3082\u7121\u304d\u306b\u3057\u3082\u975e\u305a\u3067\u3059\u3002(\u5927\u62b5\u306f\u4f55\u304b\u3057\u3089\u306e\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u30df\u30b9\u3067\u3059\u304c)<\/p>\n\n\n\n<p>\u4f59\u8ac7\u3067\u3059\u304c\u3001\u6700\u8fd1\u306e\u30b3\u30fc\u30c7\u30a3\u30f3\u30b0\u30df\u30b9\u3068\u3057\u3066<br>0 &lt; strList.size()<br>\u3068\u304b\u66f8\u3044\u3066\u3044\u3066\u3001\u7121\u9650\u30eb\u30fc\u30d7\u3067 IndexOutOfBoundsException \u304c\u767a\u751f\u3057\u3066\u4e00\u4eba\u3067\u82e6\u7b11\u3057\u3066\u307e\u3057\u305f\u3002<\/p>\n\n\n\n<h3 class=\"wp-block-heading\">enum\uff08\u5217\u6319\u578b\uff09<\/h3>\n\n\n\n<p>\u5024\u306e\u4e00\u89a7\u3092\u5b9a\u7fa9\u3059\u308b\u6587\u6cd5\u3067\u3059\u3002<br>\u4f7f\u3044\u65b9\u306e\u4f8b\u3068\u3057\u3066\u306f\u3001\u3001\u3001<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    enum targetType {\n        target1,\n        target2\n    }\n\n    public void test() {\n        enumTest(targetType.target1);\n    }\n\n    public void enumTest(targetType target) {\n\n        switch (target) {\n            case target1:\n                \/\/ \u51e6\u7406A\n                break;\n            case target2:\n                \/\/ \u51e6\u7406B\n                break;\n        }\n    }\n[\/sourcecode]<\/pre>\n\n\n\n<p>\u3053\u306e\u69d8\u306b\u3001\u300c\u610f\u5473\u306e\u3042\u308b\uff08\u610f\u5473\u3092\u8868\u3059\uff09\u5024\u306e\u96c6\u307e\u308a\u300d\u3092\u5b9a\u7fa9\u3057\u307e\u3059\u3002\uff08\u3068\u3044\u3046\u81ea\u5206\u306e\u4e2d\u3067\u306e\u7406\u89e3\uff09<br>enum\u3092\u578b\u3068\u3057\u3066\u5f15\u6570\u306b\u6307\u5b9a\u3059\u308b\u3053\u3068\u3067\u3001\u305d\u308c\u4ee5\u5916\u306e\u5024\u3092\u8a31\u3055\u305a\u3001\u60f3\u5b9a\u5916\u306e\u5165\u529b\u3092\u9632\u3050\u3053\u3068\u304c\u51fa\u6765\u307e\u3059\u3002<br>\u307e\u305f\u3001\u4f7f\u7528\u3059\u308b\u5074\u3082\u4f55\u3092\u6307\u5b9a\u3059\u308c\u3070\u826f\u3044\u304b\u5206\u304b\u308a\u3084\u3059\u304f\u3001\u660e\u78ba\u306b\u306a\u308a\u307e\u3059\u3002<br>\u4ed6\u306b\u3082enum\u3067\u306f\u8272\u3005\u306a\u5229\u7528\u65b9\u6cd5\u304c\u3042\u308a\u307e\u3059\u304c\u3001\u3068\u308a\u3042\u3048\u305a\u4e00\u756a\u5358\u7d14\u306a\u4f7f\u3044\u65b9\u3067\u3059\u306d\u3002<\/p>\n\n\n\n<p>\u3010\u4e00\u65b91.4\u3067\u306f\u3011<\/p>\n\n\n\n<pre class=\"wp-block-preformatted\">[sourcecode language=\"java\"]\n    public static String TARGET_1 = \"1\";\n    public static String TARGET_2 = \"2\";\n\n    public void test() {\n        enumTest(TARGET_1);\n    }\n\n    public void enumTest(String target) {\n\n        if (TARGET_1.equals(target)) {\n            \/\/ \u51e6\u7406A\n        } else if (TARGET_2.equals(target)) {\n            \/\/ \u51e6\u7406B\n        } else {\n            \/\/ \u60f3\u5b9a\u5916\n        }\n    }\n[\/sourcecode]<\/pre>\n\n\n\n<p>String\u578b\uff08\u4f55\u3067\u3082\u3044\u3044\u3093\u3067\u3059\u3051\u3069\uff09\u3067\u5024\u3092\u5b9a\u7fa9\u3057\u3001if\u6587\u3067\u5224\u5b9a\u3057\u3066\u3044\u307e\u3059\u3002<br>\u203b\u4e3b\u984c\u3068\u306f\u95a2\u4fc2\u7121\u3044\u3067\u3059\u304c\u3001Java7\u304b\u3089String\u3067\u3082switch\u6587\u304c\u4f7f\u3048\u308b\u3089\u3057\u3044\u3067\u3059\u306d\u3002<\/p>\n\n\n\n<p>\u5165\u3063\u3066\u304f\u308b\u5024\u306f\u4f7f\u3046\u5074\u306b\u5b8c\u5168\u306b\u4f9d\u5b58\u3057\u307e\u3059\u3057\u3001\u4f7f\u3046\u5074\u3082\u4e00\u898b\u3057\u3066\u4f55\u3092\u6307\u5b9a\u3059\u308c\u3070\u826f\u3044\u304b\u5206\u304b\u308a\u307e\u305b\u3093\u3002<br>\u30b5\u30f3\u30d7\u30eb\u306f\u77ed\u304f\u3066\u5358\u7d14\u3067\u3059\u304c\u3001\u5b9f\u969b\u306b\u696d\u52d9\u3067\u4f5c\u6210\u3055\u308c\u308b\u3088\u3046\u306a\u30b7\u30b9\u30c6\u30e0\u3060\u3068\u3001\u5b9f\u88c5\u30b3\u30fc\u30c9\u3082\u9577\u304f\u5b9a\u6570\u5b9a\u7fa9\u3082\u591a\u3044\u3067\u3059\u3057\u3001\u5927\u62b5\u306f\u5225\u306e\u5b9a\u6570\u30af\u30e9\u30b9\u306b\u307e\u3068\u3081\u3089\u308c\u3066\u308b\u306e\u3067\u63a2\u3057\u306b\u304f\u3044\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u53e4\u304f\u304b\u3089\u4f7f\u308f\u308c\u3066\u3044\u308b\u30b7\u30b9\u30c6\u30e0\u3067\u306f\u3001\u672a\u3060\u306bJava\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u3092\u4e0a\u3052\u305a\u306b\u958b\u767a\u3092\u7d9a\u3051\u3066\u3044\u308b\u6240\u3082\u3042\u308a\u307e\u3059\u3002<br>\u7406\u7531\u306f\u69d8\u3005\u3060\u3068\u601d\u308f\u308c\u307e\u3059\u304c\u3001\u805e\u3044\u305f\u8a71\u306e\u3072\u3068\u3064\u3067\u306f\u3001\u300c\u30d0\u30fc\u30b8\u30e7\u30f3\u3092\u4e0a\u3052\u305f\u4e8b\u306b\u3088\u308b\u5f71\u97ff\u8abf\u67fb\u3068\u52d5\u4f5c\u78ba\u8a8d\u306b\u639b\u3051\u308b\u304a\u91d1\u306f\u7121\u3044\u300d\u3068\u3044\u3046\u4e8b\u3067\u3059\u3002<br>\u203b\u3061\u306a\u307f\u306b\u73fe\u5728\u306e\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306f\u7121\u304f\u3001\u4ee5\u524d\u95a2\u308f\u3063\u3066\u3044\u305f\u3082\u306e\u3067\u3059\u3002<\/p>\n\n\n\n<p>\u30b7\u30b9\u30c6\u30e0\u3092\u4f7f\u3046\u5074\u304b\u3089\u898b\u308c\u3070\u3001\u52d5\u4f5c\u306f\u5909\u308f\u3089\u306a\u3044\u306e\u306b\u8cbb\u7528\u3092\u639b\u3051\u308b\u7406\u7531\u306f\u7121\u3044\u2026\u3068\u3044\u3046\u306e\u306f\u307e\u3041\u81f3\u6975\u6700\u3082\u3067\u306f\u3042\u308a\u307e\u3059\u3002<br>\u304c\u3001\u305d\u308c\u3092\u7d9a\u3051\u305f\u5834\u5408\u306e\u6570\u5e74\uff5e\u6570\u5341\u5e74\u5358\u4f4d\u3067\u306e\u30ea\u30b9\u30af\u3084\u30e9\u30f3\u30cb\u30f3\u30b0\u30b3\u30b9\u30c8\u306f\u5897\u3048\u3066\u3044\u304f\u3093\u3058\u3083\u306a\u3044\u304b\u306a\u3041\u3068\u601d\u3063\u305f\u308a\u3057\u307e\u3059\u3002<br>\u79c1\u306e\u52dd\u624b\u306a\u60f3\u50cf\u3067\u3059\u3051\u308c\u3069\u3002<\/p>\n\n\n\n<p>\u305d\u3093\u306a\u3068\u3053\u308d\u3067\u4eca\u56de\u306f\u3053\u306e\u8fba\u308a\u3067\u5931\u793c\u3057\u307e\u3059\u3002<\/p>\n<div class=\"opent-_2\" style=\"margin-top: 10px;margin-right: 10px;margin-bottom: 10px;margin-left: 10px;\" id=\"opent-1520514692\"><a href=\"https:\/\/www.opentone.co.jp\/backlog\/\" aria-label=\"twitter_backlogskt_new\"><img src=\"https:\/\/www.opentone.co.jp\/ot-lab\/wp-content\/uploads\/sites\/11\/2023\/02\/twitter_backlogskt_new.jpg\" alt=\"\"  srcset=\"https:\/\/www.opentone.co.jp\/ot-lab\/wp-content\/uploads\/sites\/11\/2023\/02\/twitter_backlogskt_new.jpg 1024w, https:\/\/www.opentone.co.jp\/ot-lab\/wp-content\/uploads\/sites\/11\/2023\/02\/twitter_backlogskt_new-300x157.jpg 300w, https:\/\/www.opentone.co.jp\/ot-lab\/wp-content\/uploads\/sites\/11\/2023\/02\/twitter_backlogskt_new-768x401.jpg 768w\" sizes=\"(max-width: 1024px) 100vw, 1024px\" width=\"384\" height=\"200\"   \/><\/a><\/div>","protected":false},"excerpt":{"rendered":"<p>\u3053\u3093\u306b\u3061\u306f\u3002kk\u3067\u3059\u3002 \u73fe\u5728\u95a2\u308f\u3063\u3066\u3044\u308b\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306f\u3001Java\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u304c1.4\u3068\u306a\u3063\u3066\u3044\u307e\u3059<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_uag_custom_page_level_css":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[28],"tags":[11],"class_list":["post-898","post","type-post","status-publish","format-standard","hentry","category-web-system","tag-java",""],"acf":[],"aioseo_notices":[],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false,"engage-mag-carousel-img":false,"engage-mag-carousel-img-landscape":false,"engage-mag-carousel-large-img":false,"engage-mag-carousel-large-img-landscape":false,"engage-mag-large-thumb":false,"engage-mag-small-thumb":false},"uagb_author_info":{"display_name":"ah106rx4o4","author_link":"https:\/\/www.opentone.co.jp\/ot-lab\/author\/ah106rx4o4"},"uagb_comment_info":0,"uagb_excerpt":"\u3053\u3093\u306b\u3061\u306f\u3002kk\u3067\u3059\u3002 \u73fe\u5728\u95a2\u308f\u3063\u3066\u3044\u308b\u30d7\u30ed\u30b8\u30a7\u30af\u30c8\u3067\u306f\u3001Java\u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u304c1.4\u3068\u306a\u3063\u3066\u3044\u307e\u3059","_links":{"self":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts\/898","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/comments?post=898"}],"version-history":[{"count":1,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts\/898\/revisions"}],"predecessor-version":[{"id":899,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/posts\/898\/revisions\/899"}],"wp:attachment":[{"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/media?parent=898"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/categories?post=898"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.opentone.co.jp\/ot-lab\/wp-json\/wp\/v2\/tags?post=898"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}