{"id":71708,"date":"2024-02-20T11:40:48","date_gmt":"2024-02-20T03:40:48","guid":{"rendered":"https:\/\/docs.pingcode.com\/?p=71708"},"modified":"2024-02-20T11:51:55","modified_gmt":"2024-02-20T03:51:55","slug":"java%e5%8f%8d%e5%b0%84%e6%80%8e%e4%b9%88%e5%ae%9e%e7%8e%b0%e7%9a%84","status":"publish","type":"post","link":"https:\/\/docs.pingcode.com\/ask\/71708.html","title":{"rendered":"java\u53cd\u5c04\u600e\u4e48\u5b9e\u73b0\u7684"},"content":{"rendered":"<p style=\"text-align:center;\" ><img fetchpriority=\"high\" decoding=\"async\" class=\"alignnone size-full wp-image-71754\" src=\"https:\/\/cdn-docs.pingcode.com\/wp-content\/uploads\/2024\/02\/img-hB2Ip3VtMnw0F5lrKcUDrkG3.png?x-oss-process=image\/auto-orient,1\/format,webp\" width=\"600\" height=\"342\" alt=\"java\u53cd\u5c04\u600e\u4e48\u5b9e\u73b0\u7684\" \/><\/p>\n<p>\u5728\u6df1\u5165\u63a2\u8ba8Java\u53cd\u5c04\u7684\u5b9e\u73b0\u65b9\u5f0f\u4e4b\u524d\uff0c\u8ba9\u6211\u4eec\u5148\u76f4\u63a5\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\u3002<strong>Java\u53cd\u5c04\u673a\u5236\u5141\u8bb8\u7a0b\u5e8f\u5728\u8fd0\u884c\u65f6\u52a0\u8f7d\u3001\u63a2\u67e5\u3001\u548c\u4f7f\u7528\u7f16\u8bd1\u671f\u95f4\u5b8c\u5168\u672a\u77e5\u7684classes<\/strong>\u3002\u5177\u4f53\u6765\u8bf4\uff0c\u8fd9\u4e00\u673a\u5236\u4e3b\u8981\u4f9d\u9760<strong>ClassLoader\u52a0\u8f7d\u7c7b\u5b57\u8282\u7801\u3001JVM\u5728\u8fd0\u884c\u65f6\u521b\u5efa\u5bf9\u5e94\u7684Class\u5bf9\u8c61\u3001\u4ee5\u53ca\u901a\u8fc7\u8fd9\u4e2aClass\u5bf9\u8c61\u8bbf\u95ee\u7c7b\u7684\u6784\u9020\u5668\u3001\u65b9\u6cd5\u548c\u5b57\u6bb5<\/strong>\u3002\u5176\u4e2d\uff0cClassLoader\u7684\u89d2\u8272\u5c24\u4e3a\u5173\u952e\uff0c\u5b83\u8d1f\u8d23\u5c06\u7c7b\u7684\u5b57\u8282\u7801\u52a0\u8f7d\u5230JVM\u4e2d\u3002\u4e00\u65e6\u7c7b\u88ab\u52a0\u8f7d\uff0cJVM\u5c31\u4f1a\u4e3a\u4e4b\u521b\u5efa\u4e00\u4e2aClass\u7c7b\u578b\u7684\u5bf9\u8c61\uff0c\u6b64\u5bf9\u8c61\u5305\u542b\u4e86\u7c7b\u7684\u6240\u6709\u4fe1\u606f\uff0c\u5305\u62ec\u7c7b\u7684\u6210\u5458\u53d8\u91cf\u3001\u65b9\u6cd5\u7b49\u3002\u901a\u8fc7\u8fd9\u4e2aClass\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u5b9e\u73b0\u5bf9\u7c7b\u7684\u4efb\u610f\u64cd\u4f5c\uff0c\u8fd9\u5c31\u662f\u53cd\u5c04\u7684\u6838\u5fc3\u3002<\/p>\n<p>ClassLoader\u4e0d\u4ec5\u4ec5\u662f\u53cd\u5c04\u5b9e\u73b0\u7684\u57fa\u77f3\uff0c\u5b83\u5728Java\u8fd0\u884c\u65f6\u73af\u5883\u4e2d\u626e\u6f14\u7740\u6781\u4e3a\u91cd\u8981\u7684\u89d2\u8272\u3002\u5f53\u7a0b\u5e8f\u9700\u8981\u4f7f\u7528\u67d0\u4e2a\u7c7b\u65f6\uff0cClassLoader\u8d1f\u8d23\u5c06\u8fd9\u4e2a\u7c7b\u7684.class\u6587\u4ef6\u52a0\u8f7d\u5230JVM\u4e2d\u3002\u8fd9\u4e2a\u8fc7\u7a0b\u5206\u4e3a\u52a0\u8f7d\u3001\u94fe\u63a5\uff08\u9a8c\u8bc1\u3001\u51c6\u5907\u3001\u89e3\u6790\uff09\u548c\u521d\u59cb\u5316\u4e09\u4e2a\u9636\u6bb5\u3002\u5728\u52a0\u8f7d\u9636\u6bb5\uff0cClassLoader\u5c06\u5b57\u8282\u7801\u8f6c\u6362\u6210JVM\u5185\u90e8\u7684\u8868\u793a\u5f62\u5f0f\uff1b\u94fe\u63a5\u9636\u6bb5\u5219\u8d1f\u8d23\u9a8c\u8bc1\u5b57\u8282\u7801\u7684\u6b63\u786e\u6027\u3001\u4e3a\u9759\u6001\u53d8\u91cf\u5206\u914d\u5185\u5b58\u4ee5\u53ca\u89e3\u6790\u7c7b\u4e0e\u7c7b\u4e4b\u95f4\u7684\u5f15\u7528\uff1b\u521d\u59cb\u5316\u9636\u6bb5\u8d1f\u8d23\u6267\u884c\u9759\u6001\u521d\u59cb\u5316\u5668\u548c\u9759\u6001\u521d\u59cb\u5316\u5757\u3002ClassLoader\u901a\u8fc7\u8fd9\u4e09\u4e2a\u9636\u6bb5\u786e\u4fdd\u4e86\u7c7b\u5728JVM\u4e2d\u7684\u6b63\u786e\u8868\u793a\uff0c\u4e3a\u53cd\u5c04\u7684\u5b9e\u73b0\u6253\u4e0b\u4e86\u575a\u5b9e\u7684\u57fa\u7840\u3002<\/p>\n<p>## \u4e00\u3001JAVA\u53cd\u5c04\u7684\u57fa\u672c\u6982\u5ff5<\/p>\n<p>Java\u53cd\u5c04\u662fJava\u8bed\u8a00\u63d0\u4f9b\u7684\u4e00\u79cd\u57fa\u672c\u529f\u80fd\uff0c\u5b83\u5141\u8bb8\u7a0b\u5e8f\u5728\u8fd0\u884c\u65f6\u67e5\u8be2\u5bf9\u8c61\u7684\u7c7b\u578b\u4fe1\u606f\u5e76\u8c03\u7528\u5bf9\u8c61\u7684\u65b9\u6cd5\u3002\u53cd\u5c04\u673a\u5236\u4e3b\u8981\u6d89\u53ca\u4ee5\u4e0b\u51e0\u4e2a\u7c7b\u548c\u63a5\u53e3\uff1a`Class`\u3001`Method`\u3001`Field`\u3001`Constructor`\u7b49\u3002<\/p>\n<p>### Class\u7c7b\u7684\u4f5c\u7528<\/p>\n<p>`Class`\u7c7b\u662f\u53cd\u5c04\u7684\u6838\u5fc3\uff0c\u6bcf\u5f53\u6211\u4eec\u52a0\u8f7d\u4e00\u4e2a\u7c7b\u65f6\uff0cJVM\u5c31\u4f1a\u4e3a\u8fd9\u4e2a\u7c7b\u521b\u5efa\u4e00\u4e2a`Class`\u5bf9\u8c61\u3002\u901a\u8fc7\u8fd9\u4e2a\u5bf9\u8c61\uff0c\u6211\u4eec\u53ef\u4ee5\u83b7\u53d6\u7c7b\u7684\u540d\u5b57\u3001\u8bbf\u95ee\u4fee\u9970\u7b26\u3001\u5305\u4fe1\u606f\u3001\u7236\u7c7b\u3001\u5b9e\u73b0\u7684\u63a5\u53e3\u3001\u65b9\u6cd5\u3001\u6784\u9020\u5668\u3001\u5b57\u6bb5\u7b49\u4fe1\u606f\u3002<\/p>\n<p>### \u4f7f\u7528Class\u7c7b\u83b7\u53d6\u7c7b\u4fe1\u606f<\/p>\n<p>\u83b7\u53d6`Class`\u5bf9\u8c61\u7684\u65b9\u6cd5\u6709\u591a\u79cd\uff0c\u6700\u76f4\u63a5\u7684\u4e00\u79cd\u662f\u4f7f\u7528`.class`\u8bed\u6cd5\uff0c\u4f8b\u5982`String.class`\u3002\u6b64\u5916\uff0c\u8fd8\u53ef\u4ee5\u901a\u8fc7\u5bf9\u8c61\u7684`getClass()`\u65b9\u6cd5\uff0c\u6216\u8005`Class.forName()`\u9759\u6001\u65b9\u6cd5\u6765\u83b7\u53d6\u3002\u4e00\u65e6\u6709\u4e86`Class`\u5bf9\u8c61\uff0c\u5c31\u53ef\u4ee5\u4f7f\u7528\u5b83\u6765\u521b\u5efa\u5bf9\u8c61\u5b9e\u4f8b\u3001\u8c03\u7528\u65b9\u6cd5\u3001\u83b7\u53d6\u548c\u8bbe\u7f6e\u5c5e\u6027\u7b49\u3002<\/p>\n<p>## \u4e8c\u3001CLASSLOADER\u7684\u89d2\u8272<\/p>\n<p>### ClassLoader\u7684\u5de5\u4f5c\u673a\u5236<\/p>\n<p>`ClassLoader`\u7684\u4e3b\u8981\u4efb\u52a1\u662f\u6309\u9700\u52a0\u8f7d\u7c7b\u3002Java\u4e2d\u7684\u7c7b\u52a0\u8f7d\u5668\u6709\u4e09\u79cd\uff1a\u5f15\u5bfc\u7c7b\u52a0\u8f7d\u5668\uff08Bootstrap ClassLoader\uff09\u3001\u6269\u5c55\u7c7b\u52a0\u8f7d\u5668\uff08Extension ClassLoader\uff09\u3001\u548c\u5e94\u7528\u7a0b\u5e8f\u7c7b\u52a0\u8f7d\u5668\uff08Application ClassLoader\uff09\u3002\u5b83\u4eec\u6784\u6210\u4e86\u4e00\u4e2a\u7236\u5b50\u5c42\u6b21\u7ed3\u6784\u3002<\/p>\n<p>### \u52a8\u6001\u52a0\u8f7d\u7c7b<\/p>\n<p>\u52a8\u6001\u52a0\u8f7d\u662f\u53cd\u5c04\u7684\u4e00\u4e2a\u91cd\u8981\u5e94\u7528\u573a\u666f\u3002\u901a\u8fc7`Class.forName()`\u65b9\u6cd5\u53ef\u4ee5\u5b9e\u73b0\u7c7b\u7684\u52a8\u6001\u52a0\u8f7d\uff0c\u8fd9\u5728\u5f88\u591aJava\u5e94\u7528\u4e2d\u5c24\u4e3a\u91cd\u8981\uff0c\u6bd4\u5982Java\u6570\u636e\u5e93\u8fde\u63a5\uff08JDBC\uff09\u3002<\/p>\n<p>## \u4e09\u3001\u53cd\u5c04\u4e2d\u7684\u65b9\u6cd5\u8c03\u7528<\/p>\n<p>### \u8c03\u7528\u65b9\u6cd5\u7684\u6d41\u7a0b<\/p>\n<p>\u901a\u8fc7\u53cd\u5c04\u8c03\u7528\u65b9\u6cd5\u9700\u8981\u5148\u83b7\u53d6`Method`\u5bf9\u8c61\uff0c\u7136\u540e\u4f7f\u7528`invoke`\u65b9\u6cd5\u6267\u884c\u3002`invoke`\u65b9\u6cd5\u7684\u7b2c\u4e00\u4e2a\u53c2\u6570\u662f\u8981\u8c03\u7528\u65b9\u6cd5\u7684\u5bf9\u8c61\uff0c\u540e\u7eed\u53c2\u6570\u662f\u65b9\u6cd5\u8c03\u7528\u65f6\u6240\u9700\u7684\u53c2\u6570\u3002<\/p>\n<p>### \u52a8\u6001\u4ee3\u7406\u548c\u53cd\u5c04<\/p>\n<p>Java\u53cd\u5c04\u673a\u5236\u8fd8\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u52a8\u6001\u4ee3\u7406\uff0c\u8fd9\u662f\u4e00\u79cd\u5f3a\u5927\u7684\u673a\u5236\uff0c\u5141\u8bb8\u5f00\u53d1\u8005\u5728\u8fd0\u884c\u65f6\u52a8\u6001\u5730\u521b\u5efa\u63a5\u53e3\u7684\u5b9e\u73b0\uff0c\u8fdb\u884c\u65b9\u6cd5\u8c03\u7528\u7684\u62e6\u622a\u3002<\/p>\n<p>## \u56db\u3001\u53cd\u5c04\u4e0e\u6027\u80fd\u8003\u91cf<\/p>\n<p>\u867d\u7136\u53cd\u5c04\u63d0\u4f9b\u4e86\u5f3a\u5927\u7684\u529f\u80fd\uff0c\u4f7f\u5f97Java\u7a0b\u5e8f\u66f4\u52a0\u7075\u6d3b\uff0c\u4f46\u5b83\u4e5f\u6709\u4e00\u5b9a\u7684\u6027\u80fd\u4ee3\u4ef7\u3002\u53cd\u5c04\u8c03\u7528\u901a\u5e38\u6bd4\u76f4\u63a5\u8c03\u7528\u65b9\u6cd5\u6162\u3002\u56e0\u6b64\uff0c\u5728\u6027\u80fd\u654f\u611f\u7684\u5e94\u7528\u4e2d\u5e94\u8c28\u614e\u4f7f\u7528\u3002<\/p>\n<p>### \u7f13\u5b58\u53cd\u5c04\u64cd\u4f5c\u7ed3\u679c<\/p>\n<p>\u4e3a\u4e86\u4f18\u5316\u6027\u80fd\uff0c\u53ef\u4ee5\u901a\u8fc7\u7f13\u5b58`Method`\u3001`Field`\u7b49\u53cd\u5c04\u5f97\u5230\u7684\u5bf9\u8c61\uff0c\u51cf\u5c11\u5bf9`Class.forName()`\u7b49\u65b9\u6cd5\u7684\u8c03\u7528\u6b21\u6570\u3002<\/p>\n<p>\u53cd\u5c04\u662fJava\u7f16\u7a0b\u4e2d\u4e00\u4e2a\u5f3a\u5927\u800c\u7075\u6d3b\u7684\u5de5\u5177\uff0c\u5b83\u4f7f\u5f97\u7a0b\u5e8f\u80fd\u591f\u8fd0\u884c\u65f6\u52a8\u6001\u5730\u52a0\u8f7d\u3001\u63a2\u67e5\u3001\u4f7f\u7528\u4efb\u4f55Java\u7c7b\u3002\u7136\u800c\uff0c\u6b63\u5982\u6211\u4eec\u6240\u8ba8\u8bba\u7684\uff0c\u6b63\u786e\u548c\u6709\u6548\u5730\u4f7f\u7528\u53cd\u5c04\u673a\u5236\u9700\u8981\u6df1\u5165\u7406\u89e3\u5176\u80cc\u540e\u7684\u539f\u7406\u548c\u6f5c\u5728\u7684\u6027\u80fd\u5f71\u54cd\u3002\u901a\u8fc7\u5408\u7406\u5229\u7528ClassLoader\u3001\u7f13\u5b58\u5173\u952e\u5bf9\u8c61\u548c\u65b9\u6cd5\uff0c\u5e76\u5728\u9002\u5f53\u7684\u573a\u5408\u9009\u62e9\u53cd\u5c04\uff0c\u53ef\u4ee5\u5728\u4fdd\u8bc1\u7a0b\u5e8f\u7075\u6d3b\u6027\u7684\u540c\u65f6\uff0c\u6700\u5927\u9650\u5ea6\u5730\u51cf\u5c11\u6027\u80fd\u635f\u5931\u3002<\/p>\n<h2><strong>\u76f8\u5173\u95ee\u7b54FAQs\uff1a<\/strong><\/h2>\n<p><strong>\u5982\u4f55\u5728Java\u4e2d\u4f7f\u7528\u53cd\u5c04\uff1f<\/strong><\/p>\n<p>\u5728Java\u4e2d\uff0c\u53cd\u5c04\u53ef\u4ee5\u901a\u8fc7Class\u7c7b\u7684\u76f8\u5173\u65b9\u6cd5\u6765\u5b9e\u73b0\u3002\u901a\u8fc7Class.forName()\u65b9\u6cd5\u53ef\u4ee5\u83b7\u53d6\u7c7b\u7684Class\u5bf9\u8c61\uff0c\u7136\u540e\u53ef\u4ee5\u901a\u8fc7Class\u5bf9\u8c61\u83b7\u53d6\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\u3001\u6210\u5458\u53d8\u91cf\u3001\u65b9\u6cd5\u7b49\u4fe1\u606f\u3002\u901a\u8fc7Method\u7c7b\u548cField\u7c7b\u53ef\u4ee5\u64cd\u4f5c\u65b9\u6cd5\u548c\u6210\u5458\u53d8\u91cf\uff0c\u5b9e\u73b0\u5bf9\u7c7b\u7684\u52a8\u6001\u64cd\u4f5c\u3002<\/p>\n<p><strong>\u5728Java\u4e2d\uff0c\u53cd\u5c04\u7684\u4f5c\u7528\u662f\u4ec0\u4e48\uff1f<\/strong><\/p>\n<p>\u53cd\u5c04\u5728Java\u4e2d\u53ef\u4ee5\u5b9e\u73b0\u52a8\u6001\u52a0\u8f7d\u548c\u4f7f\u7528\u7c7b\u4fe1\u606f\uff0c\u53ef\u4ee5\u5728\u8fd0\u884c\u65f6\u83b7\u53d6\u7c7b\u7684\u4fe1\u606f\u5e76\u64cd\u4f5c\u7c7b\u7684\u6210\u5458\u3001\u65b9\u6cd5\uff0c\u53ef\u4ee5\u5b9e\u73b0\u7075\u6d3b\u7684\u7a0b\u5e8f\u8bbe\u8ba1\u3002\u901a\u8fc7\u53cd\u5c04\uff0c\u53ef\u4ee5\u5b9e\u73b0\u52a8\u6001\u4ee3\u7406\u3001\u52a8\u6001\u751f\u6210\u7c7b\u5b9e\u4f8b\u3001\u8c03\u7528\u79c1\u6709\u65b9\u6cd5\u548c\u5904\u7406\u6ce8\u89e3\u7b49\u529f\u80fd\u3002<\/p>\n<p><strong>Java\u53cd\u5c04\u53ef\u4ee5\u7528\u6765\u89e3\u51b3\u4ec0\u4e48\u95ee\u9898\uff1f<\/strong><\/p>\n<p>Java\u53cd\u5c04\u53ef\u4ee5\u7528\u6765\u5b9e\u73b0\u6846\u67b6\u5f00\u53d1\u4e2d\u7684\u63d2\u4ef6\u673a\u5236\uff0c\u53ef\u4ee5\u52a8\u6001\u52a0\u8f7d\u7c7b\u3001\u5b9e\u73b0\u914d\u7f6e\u6587\u4ef6\u9a71\u52a8\u7684\u7a0b\u5e8f\u8bbe\u8ba1\uff0c\u53ef\u4ee5\u5b9e\u73b0\u8bbe\u8ba1\u6a21\u5f0f\u4e2d\u7684\u4ee3\u7406\u6a21\u5f0f\u548c\u88c5\u9970\u5668\u6a21\u5f0f\u3002\u901a\u8fc7\u53cd\u5c04\uff0c\u53ef\u4ee5\u5728\u8fd0\u884c\u65f6\u4fee\u6539\u7c7b\u7684\u884c\u4e3a\uff0c\u5b9e\u73b0\u66f4\u52a0\u7075\u6d3b\u548c\u6269\u5c55\u6027\u5f3a\u7684\u7a0b\u5e8f\u8bbe\u8ba1\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"\u5728\u6df1\u5165\u63a2\u8ba8Java\u53cd\u5c04\u7684\u5b9e\u73b0\u65b9\u5f0f\u4e4b\u524d\uff0c\u8ba9\u6211\u4eec\u5148\u76f4\u63a5\u56de\u7b54\u8fd9\u4e2a\u95ee\u9898\u3002Java\u53cd\u5c04\u673a\u5236\u5141\u8bb8\u7a0b\u5e8f\u5728\u8fd0\u884c\u65f6\u52a0\u8f7d\u3001\u63a2\u67e5\u3001\u548c 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