{"id":47992,"date":"2023-12-12T20:57:17","date_gmt":"2023-12-12T12:57:17","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=47992"},"modified":"2023-12-12T21:27:07","modified_gmt":"2023-12-12T13:27:07","slug":"nan-bei-ruan-jian","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/12\/12\/nan-bei-ruan-jian\/","title":{"rendered":"\u5357\u5317\u8f6f\u4ef6"},"content":{"rendered":"<h1>\u5357\u5317\u8f6f\u4ef6<\/h1>\n<h2>\u4e00\u3001\u95ee\u9898\u7c7b<\/h2>\n<h3>1\u3001java \u4e2d\u5b9e\u73b0\u591a\u6001\u7684\u673a\u5236\u662f\u4ec0\u4e48?<\/h3>\n<ol>\n<li><strong>\u65b9\u6cd5\u7684\u91cd\u8f7d\uff08Overloading\uff09<\/strong>\uff1a\n<ul>\n<li>\u540c\u4e00\u4e2a\u7c7b\u4e2d\u53ef\u4ee5\u6709\u591a\u4e2a\u540c\u540d\u7684\u65b9\u6cd5\uff0c\u4f46\u662f\u8fd9\u4e9b\u65b9\u6cd5\u7684\u53c2\u6570\u5217\u8868\uff08\u5305\u62ec\u7c7b\u578b\u3001\u4e2a\u6570\u548c\u987a\u5e8f\uff09\u5fc5\u987b\u4e0d\u540c\u3002<\/li>\n<li>\u7f16\u8bd1\u5668\u901a\u8fc7\u68c0\u67e5\u8c03\u7528\u65b9\u6cd5\u65f6\u63d0\u4f9b\u7684\u53c2\u6570\u6765\u51b3\u5b9a\u8c03\u7528\u54ea\u4e2a\u65b9\u6cd5\u7248\u672c\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u5728\u7f16\u8bd1\u65f6\u671f\u5c31\u5df2\u5b8c\u6210\uff0c\u56e0\u6b64\u79f0\u4e3a\u7f16\u8bd1\u65f6\u591a\u6001\u6216\u9759\u6001\u591a\u6001\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u65b9\u6cd5\u7684\u8986\u76d6\uff08Overriding\uff09<\/strong>\uff1a\n<ul>\n<li>\u5b50\u7c7b\u53ef\u4ee5\u91cd\u65b0\u5b9a\u4e49\u7236\u7c7b\u4e2d\u5df2\u7ecf\u5b58\u5728\u7684\u975e\u79c1\u6709\uff08private\uff09\u7684\u65b9\u6cd5\u3002\u5b50\u7c7b\u4e2d\u7684\u8fd9\u4e2a\u65b9\u6cd5\u5fc5\u987b\u4e0e\u7236\u7c7b\u4e2d\u7684\u65b9\u6cd5\u5177\u6709\u76f8\u540c\u7684\u8fd4\u56de\u7c7b\u578b\u3001\u65b9\u6cd5\u540d\u548c\u53c2\u6570\u5217\u8868\u3002<\/li>\n<li>\u5f53\u4f7f\u7528\u7236\u7c7b\u5f15\u7528\u6307\u5411\u5b50\u7c7b\u5b9e\u4f8b\u5bf9\u8c61\u65f6\uff0c\u901a\u8fc7\u7236\u7c7b\u5f15\u7528\u8c03\u7528\u88ab\u8986\u76d6\u7684\u65b9\u6cd5\uff0c\u5b9e\u9645\u6267\u884c\u7684\u662f\u5b50\u7c7b\u7684\u65b9\u6cd5\u7248\u672c\u3002\u8fd9\u4e2a\u7ed1\u5b9a\u8fc7\u7a0b\u662f\u5728\u8fd0\u884c\u65f6\u671f\u52a8\u6001\u5b8c\u6210\u7684\uff0c\u6240\u4ee5\u88ab\u79f0\u4e3a\u8fd0\u884c\u65f6\u591a\u6001\u6216\u52a8\u6001\u591a\u6001\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>2\u3001\u662f\u5426\u53ef\u4ee5\u4ece\u4e00\u4e2a static \u65b9\u6cd5\u5185\u90e8\u53d1\u51fa\u5bf9\u975e static \u65b9\u6cd5\u7684\u8c03\u7528\uff0c\u4e3a\u4ec0\u4e48?<\/h3>\n<p><strong>\u4e0d\u53ef\u4ee5<\/strong>\uff0c\u9759\u6001\u65b9\u6cd5\u53ea\u80fd\u8bbf\u95ee\u9759\u6001\u6210\u5458\uff0c\u56e0\u4e3a\u975e\u9759\u6001\u65b9\u6cd5\u7684\u8c03\u7528\u8981\u5148\u521b\u5efa\u5bf9\u8c61\uff0c\u5728\u8c03\u7528\u9759\u6001\u65b9\u6cd5\u65f6\u53ef\u80fd\u5bf9\u8c61\u5e76\u6ca1\u6709\u88ab\u521d\u59cb\u5316<\/p>\n<p>\u56e0\u4e3a\u975e<a href=\"https:\/\/so.csdn.net\/so\/search?q=static&amp;spm=1001.2101.3001.7020\">static<\/a>\u65b9\u6cd5\u662f\u8981\u4e0e\u5bf9\u8c61\u5173\u8054\u5728\u4e00\u8d77\u7684\uff0c\u5fc5\u987b\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\u540e\uff0c\u624d\u53ef\u4ee5\u5728\u8be5\u5bf9\u8c61\u4e0a\u8fdb\u884c\u65b9\u6cd5\u8c03\u7528\uff0c\u800cstatic\u65b9\u6cd5\u8c03\u7528\u65f6\u4e0d\u9700\u8981\u521b\u5efa\u5bf9\u8c61\uff0c\u53ef\u4ee5\u76f4\u63a5\u8c03\u7528\u3002<br \/>\n\u4e5f\u5c31\u662f\u8bf4\uff0c\u5f53\u4e00\u4e2astatic\u65b9\u6cd5\u88ab\u8c03\u7528\u65f6\uff0c\u53ef\u80fd\u8fd8\u6ca1\u6709\u521b\u5efa\u4efb\u4f55\u5b9e\u4f8b\u5bf9\u8c61\uff0c\u5982\u679c\u4ece\u4e00\u4e2astatic\u65b9\u6cd5\u4e2d\u53d1\u51fa\u5bf9\u975estatic\u65b9\u6cd5\u7684\u8c03\u7528\uff0c\u90a3\u4e2a\u975estatic\u65b9\u6cd5\u5173\u8054\u5230\u90a3\u4e2a\u5bf9\u8c61\u4e0a\u7684\u5462\uff1f\u8fd9\u4e2a\u903b\u8f91\u65e0\u6cd5\u6210\u7acb\uff0c\u6240\u4ee5\uff0c\u4e00\u4e2astatic\u65b9\u6cd5\u5185\u90e8\u4e0d\u80fd\u53d1\u51fa\u5bf9\u975estatic\u65b9\u6cd5\u7684\u8c03\u7528\u3002<\/p>\n<p>static\u65b9\u6cd5\u662f\u9759\u6001\u65b9\u6cd5\uff0c\u662f\u5c5e\u4e8e\u7c7b\u7684\u65b9\u6cd5\uff1b\u975estatic\u65b9\u6cd5\u662f\u5c5e\u4e8e\u5bf9\u8c61\u7684\u65b9\u6cd5\uff0c\u6240\u4ee5\u5728static\u65b9\u6cd5\u4e2d\u60f3\u8981\u8c03\u7528\u975estatic\u65b9\u6cd5\uff0c\u8981\u5148\u65b0\u521b\u5efa\u4e00\u4e2a\u5bf9\u8c61\uff0c\u518d\u6709\u8fd9\u4e2a\u5bf9\u8c61\u6765\u8c03\u7528\u975estatic\u65b9\u6cd5\u3002<\/p>\n<h3>3\u3001\u9759\u6001\u53d8\u91cf\u548c\u5b9e\u4f8b\u53d8\u91cf\u7684\u533a\u522b?<\/h3>\n<ol>\n<li><strong>\u5b58\u50a8\u4f4d\u7f6e<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u5b58\u50a8\u5728\u65b9\u6cd5\u533a\u4e2d\uff0c\u4e0e\u7c7b\u76f8\u5173\u8054\uff0c\u56e0\u6b64\u5c5e\u4e8e\u6574\u4e2a\u7c7b\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u5b58\u50a8\u5728\u5806\u5185\u5b58\u4e2d\uff0c\u4e0e\u5bf9\u8c61\u76f8\u5173\u8054\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u81ea\u5df1\u7684\u526f\u672c\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u751f\u547d\u5468\u671f<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u7684\u751f\u547d\u5468\u671f\u4ece\u7c7b\u52a0\u8f7d\u65f6\u5f00\u59cb\uff0c\u76f4\u5230\u7a0b\u5e8f\u7ed3\u675f\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u7684\u751f\u547d\u5468\u671f\u4ece\u521b\u5efa\u5bf9\u8c61\u65f6\u5f00\u59cb\uff0c\u5230\u5bf9\u8c61\u88ab\u5783\u573e\u56de\u6536\u65f6\u7ed3\u675f\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u8bbf\u95ee\u65b9\u5f0f<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u53ef\u4ee5\u901a\u8fc7\u7c7b\u540d\u76f4\u63a5\u8bbf\u95ee\uff0c\u4e0d\u9700\u8981\u521b\u5efa\u4efb\u4f55\u5bf9\u8c61\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u53ea\u80fd\u901a\u8fc7\u521b\u5efa\u7684\u5bf9\u8c61\u6765\u8bbf\u95ee\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u521d\u59cb\u5316\u65f6\u673a<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u5728\u7c7b\u52a0\u8f7d\u65f6\u5c31\u4f1a\u88ab\u521d\u59cb\u5316\uff0c\u5e76\u4e14\u53ea\u521d\u59cb\u5316\u4e00\u6b21\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u5728\u521b\u5efa\u5bf9\u8c61\u65f6\u624d\u4f1a\u88ab\u521d\u59cb\u5316\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u4f1a\u6709\u81ea\u5df1\u7684\u521d\u59cb\u5316\u503c\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u4f5c\u7528\u57df<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u7684\u4f5c\u7528\u57df\u5728\u6574\u4e2a\u7c7b\u5185\uff0c\u6240\u6709\u8be5\u7c7b\u7684\u5bf9\u8c61\u90fd\u53ef\u4ee5\u8bbf\u95ee\u5230\u540c\u4e00\u4e2a\u9759\u6001\u53d8\u91cf\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u7684\u4f5c\u7528\u57df\u4ec5\u9650\u4e8e\u5bf9\u8c61\u5185\u90e8\uff0c\u6bcf\u4e2a\u5bf9\u8c61\u90fd\u6709\u81ea\u5df1\u7684\u5b9e\u4f8b\u53d8\u91cf\u526f\u672c\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u4fee\u9970\u5173\u952e\u5b57<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u4f7f\u7528 <code>static<\/code> \u5173\u952e\u5b57\u8fdb\u884c\u4fee\u9970\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u65e0\u9700\u4f7f\u7528\u7279\u6b8a\u7684\u5173\u952e\u5b57\uff0c\u5982\u679c\u6ca1\u6709\u663e\u5f0f\u58f0\u660e\u4e3a static\uff0c\u90a3\u4e48\u5b83\u9ed8\u8ba4\u5c31\u662f\u5b9e\u4f8b\u53d8\u91cf\u3002<\/li>\n<\/ul>\n<\/li>\n<li><strong>\u591a\u7ebf\u7a0b\u73af\u5883\u4e2d\u7684\u884c\u4e3a<\/strong>\uff1a\n<ul>\n<li>\u9759\u6001\u53d8\u91cf\u5728\u591a\u7ebf\u7a0b\u73af\u5883\u4e0b\u5171\u4eab\uff0c\u53ef\u80fd\u9700\u8981\u540c\u6b65\u63a7\u5236\u3002<\/li>\n<li>\u5b9e\u4f8b\u53d8\u91cf\u7531\u6bcf\u4e2a\u7ebf\u7a0b\u72ec\u7acb\u62e5\u6709\uff0c\u4e00\u822c\u60c5\u51b5\u4e0b\u4e0d\u9700\u8981\u540c\u6b65\u63a7\u5236\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<h3>4\u3001\u8bf4\u660e\u201c==\u201d\u548c\u201cequals\u201d\u533a\u522b\uff1f<\/h3>\n<ol>\n<li><strong>==<\/strong><\/li>\n<\/ol>\n<ul>\n<li><code>==<\/code> \u662f\u4e00\u4e2a\u5173\u7cfb\u8fd0\u7b97\u7b26\uff0c\u7528\u4e8e\u6bd4\u8f83\u4e24\u4e2a\u53d8\u91cf\u7684\u503c\u662f\u5426\u76f8\u7b49\u3002<\/li>\n<li>\u5bf9\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff08\u5982 int\u3001char\u3001boolean \u7b49\uff09\uff0c<code>==<\/code> \u6bd4\u8f83\u7684\u662f\u5b83\u4eec\u7684\u503c\u662f\u5426\u76f8\u7b49\u3002<\/li>\n<li>\u5bf9\u4e8e\u5f15\u7528\u6570\u636e\u7c7b\u578b\uff08\u5982 String\u3001Integer\u3001Object \u7b49\uff09\uff0c<code>==<\/code> \u6bd4\u8f83\u7684\u662f\u4e24\u4e2a\u5f15\u7528\u662f\u5426\u6307\u5411\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002\u4e5f\u5c31\u662f\u8bf4\uff0c\u5982\u679c\u4e24\u4e2a\u5f15\u7528\u53d8\u91cf\u90fd\u6307\u5411\u4e86\u5185\u5b58\u4e2d\u7684\u540c\u4e00\u4e2a\u5bf9\u8c61\uff0c\u5219 <code>==<\/code> \u8fd4\u56de true\uff1b\u5426\u5219\u8fd4\u56de false\u3002<\/li>\n<\/ul>\n<ol start=\"2\">\n<li><strong>equals()<\/strong><\/li>\n<\/ol>\n<ul>\n<li><code>equals()<\/code> \u662f Object \u7c7b\u7684\u4e00\u4e2a\u65b9\u6cd5\uff0c\u56e0\u6b64\u6240\u6709\u7c7b\u7684\u5b9e\u4f8b\u90fd\u53ef\u4ee5\u4f7f\u7528\u8fd9\u4e2a\u65b9\u6cd5\u8fdb\u884c\u6bd4\u8f83\u3002<\/li>\n<li>\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0c<code>equals()<\/code> \u65b9\u6cd5\u7684\u884c\u4e3a\u4e0e <code>==<\/code> \u76f8\u540c\uff0c\u4e5f\u662f\u6bd4\u8f83\u4e24\u4e2a\u5f15\u7528\u662f\u5426\u6307\u5411\u540c\u4e00\u4e2a\u5bf9\u8c61\u3002<\/li>\n<li>\u4f46\u662f\uff0c\u50cf String\u3001Integer \u8fd9\u6837\u7684\u7c7b\u91cd\u5199\u4e86 <code>equals()<\/code> \u65b9\u6cd5\uff0c\u4f7f\u5176\u5177\u6709\u66f4\u5177\u4f53\u7684\u8bed\u4e49\uff0c\u6bd4\u5982\u6bd4\u8f83\u5b57\u7b26\u4e32\u7684\u5185\u5bb9\u662f\u5426\u76f8\u7b49\u3002<\/li>\n<\/ul>\n<h3>5\u3001final\uff0cfinally\uff0cfinalize \u7684\u533a\u522b?<\/h3>\n<ol>\n<li>final<\/li>\n<\/ol>\n<ul>\n<li>final\u662f\u4e00\u4e2a\u4fee\u9970\u7b26\uff0c\u53ef\u4ee5\u7528\u4e8e\u7c7b\u3001\u65b9\u6cd5\u548c\u53d8\u91cf\u3002<\/p>\n<\/li>\n<li>\n<p>\u5f53\u7528\u5728\u7c7b\u4e0a\u65f6\uff0c\u8868\u793a\u8fd9\u4e2a\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f\uff0c\u4f8b\u5982\uff1a<code>public final class MyClass {}<\/code><\/p>\n<\/li>\n<li>\u5f53\u7528\u5728\u65b9\u6cd5\u4e0a\u65f6\uff0c\u8868\u793a\u8fd9\u4e2a\u65b9\u6cd5\u4e0d\u80fd\u88ab\u5b50\u7c7b\u91cd\u5199\uff0c\u4f8b\u5982\uff1a<code>public final void myMethod() {}<\/code><\/li>\n<li>\u5f53\u7528\u5728\u53d8\u91cf\uff08\u5305\u62ec\u6210\u5458\u53d8\u91cf\u548c\u5c40\u90e8\u53d8\u91cf\uff09\u4e0a\u65f6\uff1a\n<ul>\n<li>\u5bf9\u4e8e\u57fa\u672c\u6570\u636e\u7c7b\u578b\uff0c\u8868\u793a\u8be5\u53d8\u91cf\u4e00\u65e6\u8d4b\u503c\u540e\u5c31\u4e0d\u80fd\u518d\u66f4\u6539\u5176\u503c\u3002<\/li>\n<li>\u5bf9\u4e8e\u5f15\u7528\u7c7b\u578b\uff0c\u8868\u793a\u8be5\u53d8\u91cf\u4e0d\u80fd\u518d\u6307\u5411\u5176\u4ed6\u5bf9\u8c61\uff0c\u4f46\u5176\u5f15\u7528\u7684\u5bf9\u8c61\u5185\u90e8\u72b6\u6001\u662f\u53ef\u4ee5\u6539\u53d8\u7684\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<ol start=\"2\">\n<li>finally<\/li>\n<\/ol>\n<ul>\n<li><code>finally<\/code> \u662f Java \u5f02\u5e38\u5904\u7406\u673a\u5236\u7684\u4e00\u90e8\u5206\uff0c\u5b83\u4e0e <code>try-catch<\/code> \u5757\u4e00\u8d77\u4f7f\u7528\u3002<\/li>\n<li>\u5728\u4e00\u4e2a <code>try-catch<\/code> \u7ed3\u6784\u4e2d\uff0c\u65e0\u8bba\u662f\u5426\u629b\u51fa\u5f02\u5e38\uff0c<code>finally<\/code> \u5757\u4e2d\u7684\u4ee3\u7801\u603b\u662f\u4f1a\u88ab\u6267\u884c\u3002<\/li>\n<li><code>finally<\/code> \u5e38\u7528\u4e8e\u91ca\u653e\u8d44\u6e90\uff08\u5982\u5173\u95ed\u6587\u4ef6\u6d41\u3001\u6570\u636e\u5e93\u8fde\u63a5\u7b49\uff09\uff0c\u786e\u4fdd\u5373\u4f7f\u5728\u53d1\u751f\u5f02\u5e38\u7684\u60c5\u51b5\u4e0b\u4e5f\u80fd\u6b63\u786e\u6e05\u7406\u8d44\u6e90\u3002<\/li>\n<\/ul>\n<pre><code class=\" line-numbers\">javatry {\n    \/\/ \u4e00\u4e9b\u53ef\u80fd\u4f1a\u629b\u51fa\u5f02\u5e38\u7684\u4ee3\u7801\n} catch (Exception e) {\n    \/\/ \u5904\u7406\u5f02\u5e38\n} finally {\n    \/\/ \u6e05\u7406\u8d44\u6e90\uff0c\u8fd9\u6bb5\u4ee3\u7801\u59cb\u7ec8\u4f1a\u88ab\u6267\u884c\n}\n<\/code><\/pre>\n<ol start=\"3\">\n<li>finalize()<\/li>\n<\/ol>\n<ul>\n<li><code>finalize()<\/code> \u662f Object \u7c7b\u7684\u4e00\u4e2a protected \u65b9\u6cd5\uff0c\u5b50\u7c7b\u53ef\u4ee5\u91cd\u5199\u5b83\u3002<\/li>\n<li>\u5f53\u5783\u573e\u56de\u6536\u5668\u786e\u5b9a\u4e0d\u5b58\u5728\u5bf9\u8be5\u5bf9\u8c61\u7684\u66f4\u591a\u5f15\u7528\u65f6\uff0c\u7531\u5783\u573e\u56de\u6536\u5668\u8c03\u7528\u6b64\u65b9\u6cd5\u3002<\/li>\n<li><code>finalize()<\/code> \u7684\u4e3b\u8981\u76ee\u7684\u662f\u63d0\u4f9b\u4e00\u79cd\u6e05\u7406\u673a\u5236\uff0c\u5141\u8bb8\u5bf9\u8c61\u5728\u88ab\u9500\u6bc1\u524d\u6267\u884c\u4e00\u4e9b\u5fc5\u8981\u7684\u6e05\u7406\u5de5\u4f5c\uff0c\u6bd4\u5982\u91ca\u653e\u7cfb\u7edf\u8d44\u6e90\u6216\u5173\u95ed\u6253\u5f00\u7684\u6587\u4ef6\u3002<\/li>\n<li>\u4f7f\u7528 <code>finalize()<\/code> \u9700\u8981\u8c28\u614e\uff0c\u56e0\u4e3a\u5b83\u7684\u6267\u884c\u65f6\u673a\u4e0d\u53ef\u9884\u6d4b\uff0c\u5e76\u4e14\u53ef\u80fd\u5e26\u6765\u6027\u80fd\u95ee\u9898\u3002Java 9 \u5f00\u59cb\u5e9f\u5f03\u4e86 <code>finalize()<\/code> \u65b9\u6cd5\uff0c\u5e76\u8ba1\u5212\u5728\u672a\u6765\u7684\u7248\u672c\u4e2d\u79fb\u9664\u3002<\/li>\n<\/ul>\n<h2>\u4e8c\u3001\u8bfb\u7a0b\u5e8f<\/h2>\n<p>1\u3001 \u6267\u884c\u7ed3\u679c\u662f\uff1f<\/p>\n<pre><code class=\"language-java  line-numbers\">int x=0;\nint y=10;\ndo{\n    y--;\n    ++x;\n}while(x&lt;5);\nSystem.out.print(x+\",\"+y);\n<\/code><\/pre>\n<p>5,5<\/p>\n<p>2\u3001\u6267\u884c\u7ed3\u679c\u662f\uff1f<\/p>\n<pre><code class=\"language-java  line-numbers\">public class ClassA {\n    public int getValue() {\n        int value = 0;\n        boolean setting=true;\n        String title=\"Hello\";\n        if(value || (setting &amp;&amp; title == \"Hello\")){\n            return 1;\n        }\n        if (value == 1 &amp; title.equals(\"Hello\")){\n            return 2;\n        }\n    }\n    public static void main(String[] args) {\n        ClassA a=new ClassA();\n        a.getValue();\n    }\n}\n\n<\/code><\/pre>\n<p>\u62a5\u9519<\/p>\n<p>3\u3001\u4fee\u6539\u4ee5\u4e0b\u4ee3\u7801\u4f7f\u4e4b\u4e0d\u62a5\u9519\u3002<\/p>\n<pre><code class=\"language-java  line-numbers\"><br \/> class Super{\n     private int a;\n     protected Super(int a){\n         this.a=a;\n     }\n\n }\n class Sub extends  Super{\n     public Sub(int a){\n         super(a);\n     }\n     public Sub(){\n         this.a=5;\n     }\n }\n\n<\/code><\/pre>\n<p>\u4fee\u6539\u540e\uff1a<\/p>\n<pre><code class=\"language-java  line-numbers\"><br \/>class Super{\n    private int a;\n\n    \/\/ \u65e0\u53c2\u6570\u6784\u9020\u51fd\u6570\n    public Super() {\n        this.a = 0; \/\/ \u6216\u8005\u5176\u4ed6\u9ed8\u8ba4\u503c\n    }\n\n    protected Super(int a){\n        this.a=a;\n    }\n}\n\nclass Sub extends  Super{\n    public Sub(int a){\n        super(a);\n    }\n\n    public Sub(){\n        this.a=5;\n    }\n}\n\n<\/code><\/pre>\n<p>4\u3001\u4ee5\u4e0b\u4ee3\u7801\u6267\u884c\u7ed3\u679c\u662f\uff1f<\/p>\n<pre><code class=\"language-jav  line-numbers\">public static String join(Object a[],char link,Object nullObj)\n       {\n           if(a==null){\n               return null;\n           }\n           if(a.length==1){\n               return a[0]==null ? (nullObj==null?null:nullObj.toString()):a[0].toString();\n           }\n           final StringBuilder sb=new StringBuilder();\n           for(int i=0;i&lt;a.length;i++){\n               if(i&gt;0){\n                   sb.append(link);\n               }\n               sb.append(a[i]==null? nullObj:a[i]);\n           }\n           return sb.toString();\n       }\n      public static void main(String[] args) {\n          System.out.println(join(new Object[]{\"abc\",\"bcd\",null,\"def\"},'-',\"xxx\"));\n      }\n<\/code><\/pre>\n<p>abc-bcd-xxx-def<\/p>\n<h2>\u4e09\u3001\u6570\u636e\u5e93\u9898<\/h2>\n<p>\u8868\u7ed3\u6784\u63cf\u8ff0<br \/>\ngcode(\u5546\u54c1\u8868) : gcode(\u5546\u54c1 ID)\u3001gname(\u5546\u54c1\u540d\u79f0)\u3001type(\u5206\u7c7b)\uff1b<br \/>\npurorder(\u91c7\u8d2d\u8868):id(\u4e3b\u952e ID)\u3001gcode(\u5546\u54c1 ID)\u3001qty(\u91c7\u8d2d\u6570\u91cf)\u3001rmb(\u91c7\u8d2d\u91d1\u989d)\u3001odate(\u91c7\u8d2d\u65e5\u671f)\uff1b<br \/>\nsalorder(\u9500\u552e\u8868):id(\u4e3b\u952e ID)\u3001gcode(\u5546\u54c1 ID)\u3001qty(\u9500\u552e\u6570\u91cf)\u3001rmb(\u9500\u552e\u91d1\u989d)\u3001odate(\u9500\u552e\u4e0a\u671f)\uff1b<\/p>\n<p>\u95ee\u9898\uff1a\u8bf7\u7ed9\u51fa\u4e0b\u9762\u6bcf\u4e00\u4e2a\u67e5\u8be2\u7684 SQL \u8bed\u53e5\u3002<br \/>\n1\u3001\u627e\u51fa\u201cA\u201d\u5546\u54c1\u5728\u672c\u5e74\u7684\u91c7\u8d2d\u660e\u7ec6\uff0c\u663e\u793a\u5b57\u6bb5( \u5546\u54c1D\u3001\u5546\u54c1\u540d\u79f0\u3001\u6570\u91cf\u3001\u65e5\u671f\uff09\u3002<\/p>\n<p>2\u3001\u627e\u51fa\u5546\u54c1\u5206\u7c7b\u4e3a\u201c001\u201d\u7684\u5546\u54c1\uff0c\u5728\u672c\u5e74\u7684\u91c7\u8d2d\u6570\u91cf\u5408\u8ba1\uff0c\u663e\u793a\u5b57\u6bb5( \u5546\u54c1D\u3001\u5546\u54c1\u540d\u79f0\u3001\u6570\u91cf\uff09\u3002<\/p>\n<p>3\u3001\u51fa\u300a\u91c7\u8d2d\u9500\u552e\u4e00\u89c8\u8868\u300b\uff0c\u663e\u793a\u5b57\u6bb5( \u5546\u54c1D\u3001\u91c7\u8d2d\u6570\u91cf\u3001\u9500\u552e\u6570\u91cf\u3001\u5e93\u5b58\u6570\u91cf \uff09\u3002<\/p>\n<p>4\u3001\u627e\u51fa\u91c7\u8d2d\u6570\u91cf\u5408\u8ba1\u524d 10 \u540d\u548c\u9500\u552e\u6570\u91cf\u5408\u8ba1\u524d 10\u540d\u7684\u5546\u54c1\u7edf\u8ba1\u8868\uff0c\u663e\u793a\u5b57\u6bb5(\u7c7b\u578b(\u91c7\u8d2d\\\u9500\u552e)\u5546\u54c1ID\u3001\u6570\u91cf \u3002<\/p>\n<ol>\n<li>\u627e\u51fa\u201cA\u201d\u5546\u54c1\u5728\u672c\u5e74\u7684\u91c7\u8d2d\u660e\u7ec6\uff0c\u663e\u793a\u5b57\u6bb5( \u5546\u54c1D\u3001\u5546\u54c1\u540d\u79f0\u3001\u6570\u91cf\u3001\u65e5\u671f\uff09\u3002<\/li>\n<\/ol>\n<pre><code class=\"language-sql  line-numbers\">SELECT gcode, gname, qty, odate\nFROM purorder po\nJOIN gcode gc ON po.gcode = gc.gcode\nWHERE gname = 'A' AND YEAR(odate) = YEAR(CURDATE());\n<\/code><\/pre>\n<ol start=\"2\">\n<li>\u627e\u51fa\u5546\u54c1\u5206\u7c7b\u4e3a\u201c001\u201d\u7684\u5546\u54c1\uff0c\u5728\u672c\u5e74\u7684\u91c7\u8d2d\u6570\u91cf\u5408\u8ba1\uff0c\u663e\u793a\u5b57\u6bb5( \u5546\u54c1D\u3001\u5546\u54c1\u540d\u79f0\u3001\u6570\u91cf\uff09\u3002<\/li>\n<\/ol>\n<pre><code class=\"language-sql  line-numbers\">SELECT gcode, gname, SUM(qty) as total_qty\nFROM gcode gc\nJOIN purorder po ON gc.gcode = po.gcode\nWHERE type = '001' AND YEAR(po.odate) = YEAR(CURDATE())\nGROUP BY gcode, gname;\n<\/code><\/pre>\n<ol start=\"3\">\n<li>\u51fa\u300a\u91c7\u8d2d\u9500\u552e\u4e00\u89c8\u8868\u300b\uff0c\u663e\u793a\u5b57\u6bb5( \u5546\u54c1D\u3001\u91c7\u8d2d\u6570\u91cf\u3001\u9500\u552e\u6570\u91cf\u3001\u5e93\u5b58\u6570\u91cf \uff09\u3002\n<ul>\n<li>\u5047\u8bbe\u6709\u4e00\u4e2a\u540d\u4e3a <code>stock<\/code> \u7684\u8868\u6765\u5b58\u50a8\u5e93\u5b58\u4fe1\u606f\uff0c\u5305\u542b <code>gcode<\/code> \u548c <code>quantity<\/code> \u5b57\u6bb5\u3002<\/li>\n<li>\u5982\u679c\u6ca1\u6709\u8fd9\u6837\u7684\u8868\uff0c\u90a3\u4e48\u4f60\u53ef\u80fd\u9700\u8981\u521b\u5efa\u4e00\u4e2a\u4e34\u65f6\u7684\u4e2d\u95f4\u8868\u6765\u8ba1\u7b97\u5e93\u5b58\u91cf\uff0c\u8fd9\u4e2a\u8fc7\u7a0b\u901a\u5e38\u6d89\u53ca\u5230\u590d\u6742\u7684\u67e5\u8be2\u548c\u4e8b\u52a1\u5904\u7406\u3002<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<pre><code class=\"language-sql  line-numbers\">SELECT gcode, \n       (SELECT SUM(qty) FROM purorder WHERE gcode = gs.gcode AND YEAR(odate) = YEAR(CURDATE())) AS purchase_quantity,\n       (SELECT SUM(qty) FROM salorder WHERE gcode = gs.gcode AND YEAR(odate) = YEAR(CURDATE())) AS sales_quantity,\n       (SELECT quantity FROM stock WHERE gcode = gs.gcode) AS inventory_quantity\nFROM gcode gs;\n<\/code><\/pre>\n<ol start=\"4\">\n<li>\u627e\u51fa\u91c7\u8d2d\u6570\u91cf\u5408\u8ba1\u524d 10 \u540d\u548c\u9500\u552e\u6570\u91cf\u5408\u8ba1\u524d 10\u540d\u7684\u5546\u54c1\u7edf\u8ba1\u8868\uff0c\u663e\u793a\u5b57\u6bb5(\u7c7b\u578b(\u91c7\u8d2d\\\u9500\u552e)\u5546\u54c1ID\u3001\u6570\u91cf \uff09\u3002<\/li>\n<\/ol>\n<pre><code class=\"language-sql  line-numbers\">-- \u91c7\u8d2d\u6570\u91cf\u524d 10 \u540d\nSELECT 'purchase', gcode, SUM(qty) as total_qty\nFROM purorder\nWHERE YEAR(odate) = YEAR(CURDATE())\nGROUP BY gcode\nORDER BY total_qty DESC\nLIMIT 10;\n\nUNION ALL\n\n-- \u9500\u552e\u6570\u91cf\u524d 10 \u540d\nSELECT 'sales', gcode, SUM(qty) as total_qty\nFROM salorder\nWHERE YEAR(odate) = YEAR(CURDATE())\nGROUP BY gcode\nORDER BY total_qty DESC\nLIMIT 10;\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>\u5357\u5317\u8f6f\u4ef6 \u4e00\u3001\u95ee\u9898\u7c7b 1\u3001java \u4e2d\u5b9e\u73b0\u591a\u6001\u7684\u673a\u5236\u662f\u4ec0\u4e48? \u65b9\u6cd5\u7684\u91cd\u8f7d\uff08Overloading\uff09\uff1a \u540c\u4e00\u4e2a\u7c7b [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[106],"tags":[],"class_list":["post-47992","post","type-post","status-publish","format-standard","hentry","category-gongsi"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/47992","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=47992"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/47992\/revisions"}],"predecessor-version":[{"id":47993,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/47992\/revisions\/47993"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=47992"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=47992"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=47992"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}