{"id":421,"date":"2019-07-26T20:14:56","date_gmt":"2019-07-26T12:14:56","guid":{"rendered":"http:\/\/47.101.202.111\/?p=421"},"modified":"2019-12-19T11:25:58","modified_gmt":"2019-12-19T03:25:58","slug":"java%e5%9f%ba%e7%a1%80static%e5%85%b3%e9%94%ae%e5%ad%97%e5%92%8c%e4%bb%a3%e7%a0%81%e5%9d%97","status":"publish","type":"post","link":"http:\/\/139.196.114.170\/?p=421","title":{"rendered":"[java\u57fa\u7840]static\u5173\u952e\u5b57\u3001\u4ee3\u7801\u5757\u548c\u6267\u884c\u987a\u5e8f"},"content":{"rendered":"<p>static\u5173\u952e\u5b57\u5e94\u7528\u5728\u56de\u907f\u5b9e\u4f8b\u5316\u5bf9\u8c61\u548c\u516c\u5171\u5c5e\u6027\u7684\u573a\u666f<br \/>\nstatic\u5168\u5c40\u5c5e\u6027\u53ef\u4ee5\u5e94\u7528\u5728\u65e0\u53c2\u6784\u9020\u65b9\u6cd5\u4e2d\u8fdb\u884c<strong>\u8ba1\u6570<\/strong><\/p>\n<h4>static\u5c5e\u6027 \u89e3\u51b3\u91cd\u590d\u6570\u636e\u7684\u4fee\u6539\u4e0d\u65b9\u4fbf<\/h4>\n<p>1.\u7c7b\u7684\u5c5e\u6027\u5b58\u50a8\u5728\u5404\u81ea\u7684\u5806\u5185\u5b58\u4e2d\uff0cstatic\u5c5e\u6027\u5b58\u50a8\u5728\u5168\u5c40\u6570\u636e\u533a<br \/>\n2.\u53ef\u63d0\u51fa\u516c\u5171\u5c5e\u6027\u7528static\u4fee\u9970\uff0c\u5219\u4e00\u65e6\u4fee\u6539\u5c5e\u6027\u6240\u6709\u5bf9\u8c61\u4e2d\u7684\u5c5e\u6027\u5747\u4f1a\u4fee\u6539<br \/>\n3.static\u5c5e\u6027\u53ef\u5728\u7c7b\u672a\u5b9e\u4f8b\u5316\u65f6\u901a\u8fc7 <strong>\u7c7b\u540d.\u5c5e\u6027<\/strong> \u4f7f\u7528\uff0c\u975estatic\u5c5e\u6027\u5fc5\u987b\u5728\u5b9e\u5bf9\u8c61\u5b9e\u4f8b\u5316\u540e\u4f7f\u7528<br \/>\n4.<strong>\u79c1\u6709\u9759\u6001\u53d8\u91cf\u5728\u7c7b\u5916\u65e0\u6cd5\u76f4\u63a5\u8bbf\u95ee<\/strong>\uff0c\u5fc5\u987b\u901a\u8fc7\u7c7b\u5185\u7684public\u65b9\u6cd5\u624d\u53ef\u8bbf\u95ee\u548c\u4fee\u6539<\/p>\n<pre><code class=\"language-java \">class Another {\n    private static int y = 8;\n}\n\npublic class Test {\n    private static int x = 3;\n    public static void main(String[] args) {\n        x++; \/\/ \u4e3b\u65b9\u6cd5\u9759\u6001\u65b9\u6cd5\uff0c\u53ef\u76f4\u63a5\u8bbf\u95ee\u4e3b\u7c7b\u4e2d\u7684private static\u5c5e\u6027\n        Test.x++; \/\/ \u672c\u7c7b\u79c1\u6709\u9759\u6001\u53d8\u91cf\u53ef\u901a\u8fc7\u7c7b\u540d\u8c03\u7528\n        new Test().x++; \/\/ \u672c\u7c7b\u79c1\u6709\u9759\u6001\u53d8\u91cf\u53ef\u901a\u8fc7\u5bf9\u8c61\u8c03\u7528\n        \/\/ y++; \u65e0\u6cd5\u76f4\u63a5\u8bbf\u95ee\u5916\u90e8\u7c7b\u4e2d\u7684private static\u5c5e\u6027\n        \/\/ Another.y++; \u65e0\u6cd5\u901a\u8fc7\u7c7b\u540d\u8bbf\u95ee\u5916\u90e8\u7c7b\u79c1\u6709\u9759\u6001\u53d8\u91cf\n        \/\/ new Another().y++; \u65e0\u6cd5\u901a\u8fc7\u5bf9\u8c61\u8bbf\u95ee\u5916\u90e8\u7c7b\u79c1\u6709\u9759\u6001\u53d8\u91cf\n    }\n}\n<\/code><\/pre>\n<p>\u9759\u6001\u53d8\u91cf\u5b58\u50a8\u5728\u5168\u5c40\u533a\u57df\uff0c\u5b9e\u4f8b\u5316\u4e0d\u4f1a\u521b\u5efa\u65b0\u7684\u9759\u6001\u53d8\u91cf<\/p>\n<pre><code class=\"language-java \">public class Test {\n    private static int x = 3;\n    public static void main(String[] args) {\n        Test.x++;   \/\/ 4\n        new Test().x++; \/\/ 5\n        new Test().x++; \/\/ 6\n    }\n<\/code><\/pre>\n<h4>static\u65b9\u6cd5<\/h4>\n<p>1.static\u5c5e\u6027\u4e00\u822c\u5c01\u88c5\uff0c\u7531public static\u65b9\u6cd5\u5b9e\u73b0\u5c5e\u6027\u7684\u8bbf\u95ee\u548c\u4fee\u6539\uff0c\u65b9\u6cd5\u4e2d<strong>\u4e0d\u4f7f\u7528this\u5173\u952e\u5b57(this\u53ea\u6709\u5728\u5b9e\u4f8b\u5316\u540e\u624d\u80fd\u8bbf\u95ee)<\/strong><br \/>\n2.\u65e0\u8bba\u5b9e\u4f8b\u5316\u5bf9\u8c61\u4e0e\u5426\u5747\u53ef\u4f7f\u7528\uff0c<strong>\u7c7b\u540d\u79f0.\u65b9\u6cd5()<\/strong> \uff0c<strong>\u5b9e\u4f8b.\u65b9\u6cd5()<\/strong><br \/>\n3.static\u65b9\u6cd5\u53ea\u5141\u8bb8\u8c03\u7528static\u5c5e\u6027\u548cstatic\u65b9\u6cd5\uff08\u82e5\u8c03\u7528\u975estatic\u5c5e\u6027\u548c\u65b9\u6cd5\u901a\u8fc7\u5b9e\u4f8b\u5316\u7c7b\u6765\u8bbf\u95ee\u548c\u4fee\u6539\uff09<br \/>\n4.\u975estatic\u65b9\u6cd5\u5141\u8bb8\u8c03\u7528static\u5c5e\u6027\u548cstatic\u65b9\u6cd5<br \/>\n5.\u7c7b\u4e2d\u7684static\u65b9\u6cd5\u79f0\u4e3a <strong>\u7c7b\u65b9\u6cd5<\/strong>\uff0c\u7c7b\u4e2d\u7684\u666e\u901a\u65b9\u6cd5\u79f0\u4e3a <strong>\u5b9e\u4f8b\u65b9\u6cd5<\/strong><\/p>\n<h4>\u4ee3\u7801\u5757\u6267\u884c\u987a\u5e8f<\/h4>\n<ul>\n<li>\u666e\u901a\u4ee3\u7801\u5757 \u666e\u901a\u65b9\u6cd5\u4e2d\u53ef\u7528{}\u62c6\u5206\u4ee3\u7801<br \/>\n\u65b9\u6cd5\u4e2d\u8fdb\u884c\u7ed3\u6784\u7684\u62c6\u5206\uff0c\u9632\u6b62\u76f8\u540c\u53d8\u91cf\u540d\u79f0\u7684\u76f8\u4e92\u5f71\u54cd<\/li>\n<li>\u6784\u9020\u4ee3\u7801\u5757 \u5b9a\u4e49\u5728\u7c7b\u4e2d\u7684\u4ee3\u7801\u5757\uff0c\u533a\u522b\u4e8e\u6784\u9020\u65b9\u6cd5<br \/>\n\u5b9e\u4f8b\u5316\u65f6\u6267\u884c\uff0c\u6784\u9020\u5757\u4f18\u5148\u4e8e\u6784\u9020\u65b9\u6cd5\u6267\u884c<\/li>\n<li>\u9759\u6001\u4ee3\u7801\u5757 static\u5173\u952e\u5b57\u5b9a\u4e49\u7684\u4ee3\u7801\u5757<br \/>\n\u4e00\u822c\u7528\u4e8e\u8fdb\u884c\u7c7b\u4e2d\u9759\u6001\u5c5e\u6027\u7684\u521d\u59cb\u5316<\/li>\n<\/ul>\n<pre><code class=\"language-java \">public class Custom{\n    public Custom{\n        System.out.println(\"\u6784\u9020\u65b9\u6cd5\u6700\u540e\u6267\u884c\");\n    }\n    {\n        System.out.println(\"\u6784\u9020\u5757\u5728\u9759\u6001\u5757\u540e\u6267\u884c\");\n    }\n    static{\n        System.out.println(\"\u9759\u6001\u5757\u6700\u5148\u6267\u884c\u4e14\u53ea\u6267\u884c\u4e00\u6b21\");\n    }\n}\n\npublic static void main(String[] args){\n    new Custom();\n    new Custom();\n    new Custom();\n}\n<\/code><\/pre>\n<p>\u5728\u975e\u4e3b\u65b9\u6cd5\u6240\u5728\u7c7b\u8fdb\u884c\u9759\u6001\u5757\u5b9a\u4e49<\/p>\n<pre><code>\u9759\u6001\u5757\u6700\u5148\u6267\u884c\u4e14\u53ea\u6267\u884c\u4e00\u6b21\n\u6784\u9020\u5757\u5728\u9759\u6001\u5757\u540e\u6267\u884c\n\u6784\u9020\u65b9\u6cd5\u6700\u540e\u6267\u884c\n\u6784\u9020\u5757\u5728\u9759\u6001\u5757\u540e\u6267\u884c\n\u6784\u9020\u65b9\u6cd5\u6700\u540e\u6267\u884c\n\u6784\u9020\u5757\u5728\u9759\u6001\u5757\u540e\u6267\u884c\n\u6784\u9020\u65b9\u6cd5\u6700\u540e\u6267\u884c\n<\/code><\/pre>\n<p>\u4e3b\u7c7b\u4e2d\u8fdb\u884c\u9759\u6001\u5757\u5b9a\u4e49<\/p>\n<pre><code>\u9759\u6001\u4ee3\u7801\u5757\u4f18\u5148\u4e8e\u4e3b\u65b9\u6cd5\u6267\u884c\n<\/code><\/pre>\n<p>\u6d89\u53ca\u7ee7\u627f\u7684\u6267\u884c\u987a\u5e8f<\/p>\n<pre><code>\u7236\u7c7b\u9759\u6001\u53d8\u91cf\n\u7236\u7c7b\u9759\u6001\u4ee3\u7801\u5757\n\u5b50\u7c7b\u9759\u6001\u53d8\u91cf\n\u5b50\u7c7b\u9759\u6001\u4ee3\u7801\u5757\n\u7236\u7c7b\u975e\u9759\u6001\u53d8\u91cf\n\u7236\u7c7b\u975e\u9759\u6001\u4ee3\u7801\u5757\n\u7236\u7c7b\u6784\u9020\u65b9\u6cd5\n\u5b50\u7c7b\u975e\u9759\u6001\u53d8\u91cf\n\u5b50\u7c7b\u975e\u9759\u6001\u4ee3\u7801\u5757\n\u5b50\u7c7b\u6784\u9020\u65b9\u6cd5\n<\/code><\/pre>\n<p>\u6210\u5458\u53d8\u91cf\u603b\u662f\u6700\u5148\u6267\u884c\uff0c\u540c\u7ea7\u6309\u987a\u5e8f\u6267\u884c\uff0c<br \/>\n\u6784\u9020\u65b9\u6cd5\u91cd\u8f7d\u53ea\u6267\u884c\u8c03\u7528\u65b9\u6cd5\u9ed8\u8ba4\u6267\u884c\u65e0\u53c2<\/p>\n<h4>\u88ab\u52a8\u5f15\u7528\u95ee\u9898<\/h4>\n<p>1.\u5b50\u7c7b\u5f15\u7528\u7236\u7c7b\u9759\u6001\u5c5e\u6027\uff0c\u521d\u59cb\u5316\u7236\u7c7b\uff0c\u4e0d\u521d\u59cb\u5316\u5b50\u7c7b<\/p>\n<pre><code class=\"language-java \">    public class P {\n        public static int abc = 123;\n        static{\n            System.out.println(\"P is init\");\n        }\n    }\n\n    public class S extends P {\n        static{\n            System.out.println(\"S is init\");\n        }\n    }\n\n    public class Test {\n        public static void main(String[] args) {\n            System.out.println(S.abc);\n        }\n    }\n<\/code><\/pre>\n<p>2.\u6570\u7ec4\u5b9a\u4e49\u5f15\u7528\u7c7b\uff0c\u7c7b\u4e0d\u521d\u59cb\u5316<\/p>\n<pre><code class=\"language-java \">    public class NotInitialization {\n        public static void main(String[] args) {\n            SuperClass[] sca = new SuperClass[10];\n        }\n    }\n<\/code><\/pre>\n<p>3.\u9759\u6001\u53d8\u91cf\u5728\u7f16\u8bd1\u9636\u6bb5\u5b58\u5165\u9759\u6001\u6c60\u4e2d\uff0c\u5b9a\u4e49\u7c7b\u53d8\u91cf\u7684\u7c7b\u4e0d\u521d\u59cb\u5316<\/p>\n<pre><code class=\"language-java \">    public class ConstClass {\n        public static final int value = 123;\n        static {\n            System.out.println(\"ConstClass init!\");\n        }\n    }\n\n    public class NotInitialization{\n        public static void main(String[] args) {\n            int x = ConstClass.value;\n        }\n    }\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>static\u5173\u952e\u5b57\u5e94\u7528\u5728\u56de\u907f\u5b9e\u4f8b\u5316\u5bf9\u8c61\u548c\u516c\u5171\u5c5e\u6027\u7684\u573a\u666f static\u5168\u5c40\u5c5e\u6027\u53ef\u4ee5\u5e94\u7528\u5728\u65e0\u53c2\u6784\u9020\u65b9\u6cd5\u4e2d\u8fdb\u884c\u8ba1\u6570  &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/139.196.114.170\/?p=421\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb<span class=\"screen-reader-text\">\u201c[java\u57fa\u7840]static\u5173\u952e\u5b57\u3001\u4ee3\u7801\u5757\u548c\u6267\u884c\u987a\u5e8f\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[25],"tags":[],"jetpack_featured_media_url":"","_links":{"self":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts\/421"}],"collection":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=421"}],"version-history":[{"count":11,"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts\/421\/revisions"}],"predecessor-version":[{"id":1012,"href":"http:\/\/139.196.114.170\/index.php?rest_route=\/wp\/v2\/posts\/421\/revisions\/1012"}],"wp:attachment":[{"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=421"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=421"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/139.196.114.170\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=421"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}