{"id":95,"date":"2015-03-30T11:50:05","date_gmt":"2015-03-30T03:50:05","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=95"},"modified":"2026-08-18T12:09:25","modified_gmt":"2026-08-18T04:09:25","slug":"java-static%e5%85%b3%e9%94%ae%e5%ad%97%e4%bb%a5%e5%8f%8ajava%e9%9d%99%e6%80%81%e5%8f%98%e9%87%8f%e5%92%8c%e9%9d%99%e6%80%81%e6%96%b9%e6%b3%95","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=95","title":{"rendered":"Java static\u5173\u952e\u5b57\u4ee5\u53caJava\u9759\u6001\u53d8\u91cf\u548c\u9759\u6001\u65b9\u6cd5"},"content":{"rendered":"
\n

static<\/code> \u4fee\u9970\u53d8\u91cf\u6216\u65b9\u6cd5\uff0c\u8868\u793a\u5b83\u4eec\u662f\u9759\u6001<\/strong>\u7684\uff1a\u5c5e\u4e8e\u7c7b\uff0c\u800c\u4e0d\u5c5e\u4e8e\u67d0\u4e00\u4e2a\u5bf9\u8c61\u3002<\/p>\n

\u9759\u6001\u53d8\u91cf\u548c\u9759\u6001\u65b9\u6cd5\u53ef\u4ee5\u901a\u8fc7\u7c7b\u540d\u8bbf\u95ee\uff0c\u4e0d\u5fc5\u5148 new \u51fa\u5bf9\u8c61\uff0c\u6240\u4ee5\u4e5f\u53eb\u7c7b\u53d8\u91cf<\/strong>\u548c\u7c7b\u65b9\u6cd5<\/strong>\u3002\u5b9e\u4f8b\u53d8\u91cf\u5219\u5fc5\u987b\u901a\u8fc7\u5bf9\u8c61\u8bbf\u95ee\uff0c\u56e0\u4e3a\u6bcf\u4e2a\u5bf9\u8c61\u81ea\u5df1\u6709\u4e00\u4efd\uff0c\u503c\u53ef\u4ee5\u4e0d\u540c\u3002<\/p>\n

<\/p>\n\n\n\n\n\n\n\n
\u5bf9\u6bd4<\/th>\n\u9759\u6001\uff08\u7c7b\uff09\u6210\u5458<\/th>\n\u5b9e\u4f8b\u6210\u5458<\/th>\n<\/tr>\n<\/thead>\n
\u5185\u5b58<\/td>\n\u7c7b\u52a0\u8f7d\u65f6\u4e00\u4efd\uff0c\u6240\u6709\u5bf9\u8c61\u5171\u4eab<\/td>\n\u6bcf new \u4e00\u6b21\u5206\u914d\u4e00\u4efd<\/td>\n<\/tr>\n
\u8bbf\u95ee<\/td>\n\u63a8\u8350 \u7c7b\u540d.\u6210\u5458\uff1b\u7528\u5bf9\u8c61\u8bbf\u95ee\u4f1a\u8b66\u544a<\/td>\n\u53ea\u80fd\u901a\u8fc7\u5bf9\u8c61\uff0c\u4e0d\u80fd\u901a\u8fc7\u7c7b\u540d<\/td>\n<\/tr>\n
this \/ super<\/td>\n\u9759\u6001\u65b9\u6cd5\u91cc\u6ca1\u6709\u5f53\u524d\u5bf9\u8c61\uff0c\u4e0d\u80fd\u7528<\/td>\n\u5b9e\u4f8b\u65b9\u6cd5\u91cc\u53ef\u4ee5\u7528<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4e00\u3001\u9759\u6001\u53d8\u91cf\u4e0e\u5185\u5b58\u5206\u914d<\/h2>\n

\u7f16\u8bd1\u5668\u53ea\u4e3a\u6574\u4e2a\u7c7b\u521b\u5efa\u4e00\u4efd\u9759\u6001\u53d8\u91cf\u526f\u672c\u3002\u591a\u4e2a\u5b9e\u4f8b\u5171\u4eab\u8fd9\u5757\u5185\u5b58\uff1a\u6539 a \u5bf9\u8c61\u770b\u5230\u7684\u9759\u6001\u503c\uff0cb \u5bf9\u8c61\u7acb\u523b\u80fd\u770b\u5230\u3002\u5b9e\u4f8b\u53d8\u91cf\u4e92\u4e0d\u5f71\u54cd\u3002<\/p>\n

public class Demo {\n    static int i = 10;\n    int j;\n    Demo() {\n        this.j = 20;\n    }\n    public static void main(String[] args) {\n        System.out.println(\"\u7c7b\u53d8\u91cf i=\" + Demo.i);\n        Demo obj = new Demo();\n        System.out.println(\"\u5b9e\u4f8b\u53d8\u91cf j=\" + obj.j);\n    }\n}<\/code><\/pre>\n
\u8fd0\u884c\u7ed3\u679c\uff1a\u7c7b\u53d8\u91cf i=10\uff1b\u5b9e\u4f8b\u53d8\u91cf j=20\u3002\u518d\u770b\u5171\u4eab\u6548\u679c\uff1a<\/p>\n
public class Demo {\n    static int i;\n    int j;\n    public static void main(String[] args) {\n        Demo obj1 = new Demo();\n        obj1.i = 10;\n        obj1.j = 20;\n        Demo obj2 = new Demo();\n        System.out.println(\"obj1.i=\" + obj1.i + \", obj1.j=\" + obj1.j);\n        System.out.println(\"obj2.i=\" + obj2.i + \", obj2.j=\" + obj2.j);\n    }\n}<\/code><\/pre>\n
\u8fd0\u884c\u7ed3\u679c\uff1aobj1.i=10, obj1.j=20<\/code>\uff1bobj2.i=10, obj2.j=0<\/code>\u3002\u901a\u8fc7 obj1 \u6539 i\uff0cobj2 \u4e5f\u53d8\u6210 10\uff1bj \u5404\u6709\u4e00\u4efd\uff0cobj2.j \u4ecd\u662f\u9ed8\u8ba4\u503c 0\u3002<\/p>\n
\u9759\u6001\u53d8\u91cf\u5728\u7c7b\u88c5\u8f7d<\/strong>\u65f6\u5c31\u4f1a\u521d\u59cb\u5316\uff0c\u4e0d\u7ba1\u4f60\u7528\u4e0d\u7528\u3002\u8bbf\u95ee\u63a7\u5236\u5141\u8bb8\u65f6\u4e5f\u53ef\u4ee5\u901a\u8fc7\u5bf9\u8c61\u8bbf\u95ee\u9759\u6001\u6210\u5458\uff0c\u4f46\u4e0d\u63d0\u5021\uff0c\u7f16\u8bd1\u5668\u4f1a\u8b66\u544a\u3002\u5916\u90e8\u4e24\u79cd\u6b63\u89c4\u8bbf\u95ee\u65b9\u5f0f\uff1a\u901a\u8fc7\u5bf9\u8c61\uff0c\u6216\u901a\u8fc7\u7c7b\u540d\u3002<\/p>\n
\u4e8c\u3001\u9759\u6001\u65b9\u6cd5<\/h2>\n
\u9759\u6001\u65b9\u6cd5\u4e0d\u80fd\u5bf9\u67d0\u4e2a\u5177\u4f53\u5bf9\u8c61\u5b9e\u65bd\u64cd\u4f5c\u3002\u4f8b\u5982 Math.pow(x, a)<\/code> \u8ba1\u7b97 x \u7684 a \u6b21\u5e42\uff0c\u4e0d\u5fc5\u521b\u5efa Math \u5bf9\u8c61\u3002\u56e0\u6b64\u9759\u6001\u65b9\u6cd5\u91cc\u4e0d\u80fd\u8bbf\u95ee\u5b9e\u4f8b\u53d8\u91cf\uff0c\u53ea\u80fd\u8bbf\u95ee\u672c\u7c7b\u7684\u9759\u6001\u53d8\u91cf\u3002<\/p>\n
\u9002\u5408\u5199\u6210\u9759\u6001\u65b9\u6cd5\u7684\u60c5\u5f62\uff1a\u4e0d\u9700\u8981\u5bf9\u8c61\u72b6\u6001\u3001\u53c2\u6570\u90fd\u7531\u8c03\u7528\u65b9\u663e\u5f0f\u4f20\u5165\uff08\u5982 Math.pow<\/code>\uff09\uff1b\u6216\u8005\u53ea\u9700\u8981\u8bbf\u95ee\u7c7b\u7684\u9759\u6001\u53d8\u91cf\u3002main()<\/code> \u4e5f\u662f\u9759\u6001\u7684\u2014\u2014\u7a0b\u5e8f\u542f\u52a8\u65f6\u8fd8\u6ca1\u6709\u4efb\u4f55\u5bf9\u8c61\uff0c\u5b83\u662f\u5165\u53e3\uff0c\u8d1f\u8d23\u521b\u5efa\u540e\u9762\u8981\u7528\u7684\u5bf9\u8c61\u3002<\/p>\n
public class Demo {\n    static int sum(int x, int y) {\n        return x + y;\n    }\n    public static void main(String[] args) {\n        int sum = Demo.sum(10, 10);\n        System.out.println(\"10+10=\" + sum);\n    }\n}<\/code><\/pre>\n
\u8fd0\u884c\u7ed3\u679c\uff1a10+10=20\u3002\u89c4\u5219\u6c47\u603b\uff1a<\/p>\n
    \n
  • \n
    \u9759\u6001\u65b9\u6cd5\u53ea\u80fd\u76f4\u63a5\u8bbf\u95ee\u9759\u6001\u53d8\u91cf\uff0c\u4e0d\u80fd\u76f4\u63a5\u8c03\u7528\u975e\u9759\u6001\u65b9\u6cd5\u3002<\/section>\n<\/li>\n
  • \n
    \u9759\u6001\u65b9\u6cd5\u91cc\u6ca1\u6709 this\uff0c\u5f53\u7136\u4e5f\u4e0d\u80fd\u7528 super\u3002<\/section>\n<\/li>\n
  • \n
    \u9759\u6001\u65b9\u6cd5\u4e0d\u80fd\u88ab\u8986\u76d6\uff08\u5b50\u7c7b\u540c\u540d\u9759\u6001\u65b9\u6cd5\u662f\u9690\u85cf\uff0c\u4e0d\u662f\u591a\u6001\uff09\u3002<\/section>\n<\/li>\n
  • \n
    \u6784\u9020\u65b9\u6cd5\u4e0d\u5141\u8bb8\u58f0\u660e\u4e3a static\uff1b\u5c40\u90e8\u53d8\u91cf\u4e5f\u4e0d\u80fd\u7528 static \u4fee\u9970\u3002<\/section>\n<\/li>\n<\/ul>\n
    \u4e09\u3001\u9759\u6001\u521d\u59cb\u5668\uff08\u9759\u6001\u5757\uff09<\/h2>\n
    \u5757\u662f\u5927\u62ec\u53f7\u5305\u56f4\u7684\u4e00\u6bb5\u4ee3\u7801\u3002\u9759\u6001\u521d\u59cb\u5668\u662f\u5199\u5728\u7c7b\u91cc\u3001\u65b9\u6cd5\u5916\u9762\u7684 static \u5757\uff0c\u7c7b\u88c5\u8f7d\u65f6\uff08\u7b2c\u4e00\u6b21\u4f7f\u7528\u8be5\u7c7b\u65f6\uff09\u53ea\u6267\u884c\u4e00\u6b21\uff0c\u5e38\u7528\u6765\u521d\u59cb\u5316\u9759\u6001\u53d8\u91cf\u3002<\/p>\n
    public class Demo {\n    public static int i;\n    static {\n        i = 10;\n        System.out.println(\"Now in static block.\");\n    }\n    public void test() {\n        System.out.println(\"test method: i=\" + i);\n    }\n    public static void main(String[] args) {\n        System.out.println(\"Demo.i=\" + Demo.i);\n        new Demo().test();\n    }\n}<\/code><\/pre>\n
    \u8fd0\u884c\u7ed3\u679c\u5148\u6253\u5370\u9759\u6001\u5757\uff0c\u518d\u6253\u5370 Demo.i=10 \u548c test method: i=10\u2014\u2014\u8bbf\u95ee Demo.i<\/code> \u5c31\u4f1a\u89e6\u53d1\u7c7b\u52a0\u8f7d\uff0c\u9759\u6001\u5757\u5df2\u7ecf\u6267\u884c\u8fc7\u4e86\u3002<\/p>\n
    \u56db\u3001\u9759\u6001\u5bfc\u5165<\/h2>\n
    \u9759\u6001\u5bfc\u5165\u662f Java 5 \u7684\u7279\u6027\uff0c\u7528\u6765\u5bfc\u5165\u7c7b\u7684\u9759\u6001\u53d8\u91cf\u548c\u9759\u6001\u65b9\u6cd5\u3002\u666e\u901a\u5bfc\u5165\u662f import packageName.ClassName;<\/code>\uff1b\u9759\u6001\u5bfc\u5165\u5199\u6210\uff1a<\/p>\n
      \n
    • \n
      import static packageName.ClassName.methodName;<\/code> \u5bfc\u5165\u67d0\u4e2a\u9759\u6001\u65b9\u6cd5<\/section>\n<\/li>\n
    • \n
      import static packageName.ClassName.*;<\/code> \u5bfc\u5165\u8be5\u7c7b\u5168\u90e8\u9759\u6001\u6210\u5458<\/section>\n<\/li>\n<\/ul>\n
      \u5bfc\u5165\u540e\u53ef\u4ee5\u76f4\u63a5\u7528\u65b9\u6cd5\u540d\u8c03\u7528\uff0c\u4e0d\u5fc5\u518d\u5199 ClassName.methodName<\/code>\u3002System.out<\/code> \u91cc\u7684 out \u5c31\u662f System \u7684\u9759\u6001\u53d8\u91cf\uff0cimport static java.lang.System.*<\/code> \u4e4b\u540e\u53ef\u4ee5\u76f4\u63a5 out.println()<\/code>\u3002<\/p>\n
      import static java.lang.System.*;\nimport static java.lang.Math.random;\npublic class Demo {\n    public static void main(String[] args) {\n        out.println(\"\u4ea7\u751f\u7684\u4e00\u4e2a\u968f\u673a\u6570\uff1a\" + random());\n    }\n}<\/code><\/pre>\n
      \u8fd0\u884c\u7ed3\u679c\u7c7b\u4f3c\uff1a\u4ea7\u751f\u7684\u4e00\u4e2a\u968f\u673a\u6570\uff1a0.05800891549018705\uff08\u6bcf\u6b21\u4e0d\u540c\uff09\u3002<\/p>\n
      \n
      \u4e00\u53e5\u8bdd\u603b\u7ed3\uff1astatic \u6210\u5458\u7c7b\u52a0\u8f7d\u65f6\u4e00\u4efd\u3001\u5927\u5bb6\u5171\u7528\uff1b\u9759\u6001\u65b9\u6cd5\u6ca1\u6709 this\uff0c\u53ea\u80fd\u78b0\u9759\u6001\u7684\u4e1c\u897f\uff0c\u8981\u7528\u65f6\u5199 \u7c7b\u540d.\u6210\u5458\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"
      static \u4fee\u9970\u53d8\u91cf\u6216\u65b9\u6cd5\uff0c\u8868\u793a\u5b83\u4eec\u662f\u9759\u6001\u7684\uff1a\u5c5e\u4e8e\u7c7b\uff0c\u800c\u4e0d\u5c5e\u4e8e\u67d0\u4e00\u4e2a\u5bf9\u8c61\u3002 \u9759\u6001\u53d8\u91cf\u548c\u9759\u6001\u65b9\u6cd5\u53ef\u4ee5\u901a\u8fc7\u7c7b\u540d\u8bbf […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[16],"tags":[33,43],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/95"}],"collection":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=95"}],"version-history":[{"count":2,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/95\/revisions"}],"predecessor-version":[{"id":381,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/95\/revisions\/381"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=95"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=95"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=95"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}