{"id":109,"date":"2015-03-30T17:49:54","date_gmt":"2015-03-30T09:49:54","guid":{"rendered":"https:\/\/ai.zhousir.top\/?p=109"},"modified":"2026-08-18T12:09:26","modified_gmt":"2026-08-18T04:09:26","slug":"java%e4%b8%adnewinstance%e4%b8%8enew-%e6%af%94%e8%be%83","status":"publish","type":"post","link":"https:\/\/ai.zhousir.top\/?p=109","title":{"rendered":"Java\u4e2dnewInstance()\u4e0enew \u6bd4\u8f83"},"content":{"rendered":"
\n

\u4ece\u529f\u80fd\u4e0a\u770b\uff0cnew<\/code> \u548c newInstance()<\/code> \u90fd\u80fd\u521b\u5efa\u7c7b\u7684\u5b9e\u4f8b\u3002\u524d\u8005\u662f\u5173\u952e\u5b57\uff0c\u540e\u8005\u662f\u65b9\u6cd5\u3002\u5dee\u522b\u5728\u4e8e\uff1anewInstance()<\/code> \u8d70\u7c7b\u52a0\u8f7d\u673a\u5236\uff0c\u6309\u8fd0\u884c\u65f6\u62ff\u5230\u7684\u7c7b\u540d\u6765\u53cd\u5c04\u521b\u5efa\uff1bnew<\/code> \u5728\u6e90\u7801\u91cc\u5199\u6b7b\u7c7b\u578b\uff0c\u76f4\u63a5\u521b\u5efa\u3002<\/p>\n

\u4e3a\u4ec0\u4e48\u8981\u4e24\u79cd\u65b9\u5f0f\uff1f\u4e3b\u8981\u662f\u8f6f\u4ef6\u7684\u53ef\u4f38\u7f29\u3001\u53ef\u6269\u5c55\u3001\u53ef\u590d\u7528\uff1a\u660e\u786e\u77e5\u9053\u8981\u54ea\u4e2a\u7c7b\u65f6\u7528 new<\/code>\uff1b\u7c7b\u540d\u6765\u81ea\u914d\u7f6e\u65f6\u7528 newInstance()<\/code>\uff0c\u6362\u5b9e\u73b0\u4e0d\u7528\u6539\u8c03\u7528\u4ee3\u7801\u3002<\/p>\n

<\/p>\n

\u6ce8\u610f\uff1aClass.newInstance()<\/code> \u53ea\u80fd\u8c03\u7528\u516c\u5171\u65e0\u53c2\u6784\u9020<\/strong>\u3002Java 9 \u8d77\u8be5\u65b9\u6cd5\u5df2\u8fc7\u65f6\uff0c\u63a8\u8350 clazz.getDeclaredConstructor().newInstance()<\/code>\uff0c\u80fd\u529b\u76f8\u540c\uff0c\u5f02\u5e38\u66f4\u660e\u786e\u3002<\/p>\n\n\n\n\n\n\n\n\n
\u5bf9\u6bd4<\/th>\nnew<\/th>\nnewInstance()<\/th>\n<\/tr>\n<\/thead>\n
\u7c7b\u578b<\/td>\n\u5f3a\u7c7b\u578b\uff0c\u7f16\u8bd1\u671f\u5c31\u786e\u5b9a\u7c7b<\/td>\n\u5f31\u7c7b\u578b\uff0c\u7c7b\u540d\u53ef\u4ee5\u662f\u5b57\u7b26\u4e32<\/td>\n<\/tr>\n
\u6548\u7387<\/td>\n\u76f8\u5bf9\u9ad8<\/td>\n\u53cd\u5c04\uff0c\u76f8\u5bf9\u4f4e<\/td>\n<\/tr>\n
\u6784\u9020<\/td>\n\u53ef\u8c03\u7528\u4efb\u610f\u53ef\u89c1\u6784\u9020<\/td>\nClass.newInstance \u53ea\u80fd\u65e0\u53c2\u6784\u9020<\/td>\n<\/tr>\n
\u573a\u666f<\/td>\n\u660e\u786e\u77e5\u9053\u8981\u54ea\u4e2a\u7c7b<\/td>\n\u5de5\u5382\u3001\u914d\u7f6e\u3001\u63d2\u4ef6\u5f0f\u66ff\u6362\u5b9e\u73b0<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

\u4e00\u3001\u5de5\u5382\u6a21\u5f0f\u91cc\u4e3a\u4ec0\u4e48\u7528 newInstance<\/h2>\n

Java \u5de5\u5382\u7ecf\u5e38\u7528\u53cd\u5c04\u521b\u5efa\u5bf9\u8c61\u3002\u53d8\u91cf\u7c7b\u578b\u5199\u6210\u7236\u7c7b\u6216\u63a5\u53e3\uff0c\u8fd0\u884c\u65f6 new \u51fa\u6765\u7684\u662f\u5177\u4f53\u5b9e\u73b0\uff0c\u8c03\u7528\u65b9\u4e0d\u5fc5\u6539\u3002<\/p>\n

Class c = Class.forName(\"Example\");\nfactory = (ExampleInterface) c.newInstance();<\/code><\/pre>\n
ExampleInterface<\/code> \u662f Example \u5b9e\u73b0\u7684\u63a5\u53e3\u3002\u7c7b\u540d\u8fd8\u53ef\u4ee5\u62bd\u6210\u53d8\u91cf\uff1a<\/p>\n
String className = \"Example\";\nClass c = Class.forName(className);\nfactory = (ExampleInterface) c.newInstance();<\/code><\/pre>\n
\u518d\u8fdb\u4e00\u6b65\uff0c\u7c7b\u540d\u4ece XML \u914d\u7f6e\u8bfb\uff1a<\/p>\n
String className = readfromXMlConfig; \/\/ \u4ece xml \u914d\u7f6e\u6587\u4ef6\u4e2d\u83b7\u5f97\u5b57\u7b26\u4e32\nClass c = Class.forName(className);\nfactory = (ExampleInterface) c.newInstance();<\/code><\/pre>\n
\u8fd9\u6bb5\u4ee3\u7801\u91cc\u5df2\u7ecf\u6ca1\u6709 Example \u8fd9\u4e2a\u7c7b\u540d\u3002Example \u600e\u4e48\u6539\u3001\u751a\u81f3\u6362\u6210 Example2\u3001Example3\uff0c\u53ea\u8981\u5b83\u4eec\u5b9e\u73b0 ExampleInterface<\/code>\uff0c\u4e0a\u9762\u51e0\u884c\u90fd\u4e0d\u7528\u52a8\u3002\u8fd4\u56de\u7684\u6c38\u8fdc\u662f\u63a5\u53e3\u7c7b\u578b\uff0c\u4e0d\u662f\u67d0\u4e2a\u5199\u6b7b\u7684\u5b50\u7c7b\u3002<\/p>\n
\u4e8c\u3001\u4ece JVM \u770b\uff1anewInstance \u628a new \u62c6\u6210\u4e24\u6b65<\/h2>\n
\u7528\u5173\u952e\u5b57 new<\/code> \u65f6\uff0c\u8fd9\u4e2a\u7c7b\u5f53\u65f6\u8fd8\u6ca1\u52a0\u8f7d\u4e5f\u53ef\u4ee5\uff0c\u865a\u62df\u673a\u4f1a\u987a\u5e26\u52a0\u8f7d\u3002\u7528 newInstance()<\/code> \u5219\u5fc5\u987b\u4fdd\u8bc1\uff1a\u7c7b\u5df2\u7ecf\u52a0\u8f7d\uff0c\u5e76\u4e14\u5df2\u7ecf\u8fde\u63a5\u3002\u8fd9\u4e24\u6b65\u6b63\u662f Class.forName()<\/code> \u505a\u7684\u3002<\/p>\n
\u6240\u4ee5 newInstance()<\/code> \u76f8\u5f53\u4e8e\u628a new<\/code> \u62c6\u5f00\uff1a\u5148 forName<\/code> \u52a0\u8f7d\u67d0\u4e2a\u7c7b\uff0c\u518d\u5b9e\u4f8b\u5316\u3002\u5206\u6b65\u7684\u597d\u5904\u662f\uff1a\u52a0\u8f7d\u54ea\u4e00\u4e2a\u7c7b\u53ef\u4ee5\u653e\u5230\u8fd0\u884c\u65f6\u51b3\u5b9a\uff0c\u8c03\u7528\u70b9\u548c\u5177\u4f53\u5b9e\u73b0\u89e3\u8026\u3002<\/p>\n
\u4e09\u3001\u600e\u4e48\u9009<\/h2>\n
\u660e\u786e\u77e5\u9053\u81ea\u5df1\u8981\u4ec0\u4e48\uff0c\u76f4\u63a5 new<\/code>\u3002\u7c7b\u540d\u4ece\u914d\u7f6e\u52a0\u8f7d\u3001\u5e0c\u671b\u6362\u5b9e\u73b0\u4e0d\u6539\u6e90\u7801\uff0c\u7528 newInstance<\/code>\uff08\u6216\u6784\u9020\u5668\u4e0a\u7684 newInstance<\/code>\uff09\u3002<\/p>\n
\n
\u4e00\u53e5\u8bdd\u603b\u7ed3\uff1anew \u5f3a\u7c7b\u578b\u3001\u9ad8\u6548\u3001\u80fd\u8c03\u4efb\u610f\u6784\u9020\uff1bnewInstance \u5f31\u7c7b\u578b\u3001\u9760\u53cd\u5c04\u548c\u914d\u7f6e\u6362\u5b9e\u73b0\uff0c\u53ea\u80fd\u8d70\u65e0\u53c2\u6784\u9020\u3002<\/strong><\/p>\n<\/blockquote>\n<\/section>\n","protected":false},"excerpt":{"rendered":"
\u4ece\u529f\u80fd\u4e0a\u770b\uff0cnew \u548c newInstance() \u90fd\u80fd\u521b\u5efa\u7c7b\u7684\u5b9e\u4f8b\u3002\u524d\u8005\u662f\u5173\u952e\u5b57\uff0c\u540e\u8005\u662f\u65b9\u6cd5\u3002\u5dee\u522b\u5728\u4e8e\uff1ane […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[17],"tags":[43,35],"_links":{"self":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/109"}],"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=109"}],"version-history":[{"count":3,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/109\/revisions"}],"predecessor-version":[{"id":335,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=\/wp\/v2\/posts\/109\/revisions\/335"}],"wp:attachment":[{"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=109"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=109"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ai.zhousir.top\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=109"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}