{"id":1387,"date":"2020-04-07T10:54:30","date_gmt":"2020-04-07T02:54:30","guid":{"rendered":"https:\/\/199604.com\/?p=1387"},"modified":"2020-04-05T16:27:24","modified_gmt":"2020-04-05T08:27:24","slug":"java%e9%9d%a2%e8%af%95%e9%a2%981","status":"publish","type":"post","link":"https:\/\/199604.com\/1387","title":{"rendered":"java\u9762\u8bd5\u98981"},"content":{"rendered":"<h4>1.\u4ec0\u4e48\u662f\u91cd\u8f7d\u548c\u91cd\u5199\uff1f<\/h4>\n<p>Java \u91cc\u65b9\u6cd5\u7684\u91cd\u5199(Overriding)\u548c\u91cd\u8f7d(Overloading)\u5c31\u662f\u6307\u7684 java \u91cc\u591a\u6001\u3002<\/p>\n<p>\u91cd\u5199\u5c31\u662f\u7236\u7c7b\u4e0e\u5b50\u7c7b\u4e4b\u95f4\u7684\u591a\u6001\uff0c\u91cd\u8f7d\u662f\u5728\u4e00\u4e2a\u7c7b\u4e2d\u591a\u6001\u5bf9\u7684\u4f53\u73b0 \uff1a<\/p>\n<p>(1)\u65b9\u6cd5\u91cd\u8f7d\u662f\u4e00\u4e2a\u7c7b\u4e2d\u5b9a\u4e49\u4e86\u591a\u4e2a\u65b9\u6cd5\u540d\u76f8\u540c,\u800c\u4ed6\u4eec\u7684\u53c2\u6570\u7684\u6570\u91cf\u4e0d\u540c\u6216\u6570\u91cf\u76f8\u540c\u800c\u7c7b\u578b\u548c\u6b21\u5e8f\u4e0d\u540c,\u5219\u79f0\u4e3a\u65b9\u6cd5\u7684\u91cd\u8f7d(Overloading)\u3002<\/p>\n<p>(2)\u65b9\u6cd5\u91cd\u5199\u662f\u5728\u5b50\u7c7b\u5b58\u5728\u65b9\u6cd5\u4e0e\u7236\u7c7b\u7684\u65b9\u6cd5\u7684\u540d\u5b57\u76f8\u540c,\u800c\u4e14\u53c2\u6570\u7684\u4e2a\u6570\u4e0e\u7c7b\u578b\u4e00\u6837,\u8fd4\u56de\u503c\u4e5f\u4e00\u6837\u7684\u65b9\u6cd5,\u5c31\u79f0\u4e3a\u91cd\u5199(Overriding)\u3002<\/p>\n<h4>2.String \u4e2d\u7684==\u548c equals \u7684\u533a\u522b?<\/h4>\n<p>== \u6bd4 \u8f83 \u7684 \u662f \u5185 \u5b58 \u5730 \u5740 , equals \u6bd4 \u8f83 \u7684 \u662f \u5185 \u5bb9\uff1a<\/p>\n<pre class=\"lang:java decode:true\">String a=\"abc\"\r\n\r\nString b=\"abc\"\r\n\r\nSystem.out.println(a==b)\r\n\r\n\u8f93\u51fa\u7684\u662f false.<\/pre>\n<h4>3.Final \u5173\u952e\u5b57<\/h4>\n<p>\u5176\u5b9e final\u662f\u4e00\u4e2a\u5b89\u5168\u4fee\u9970\u7b26,\u5c31\u662f\u7528 final \u4fee\u9970\u7684\u7c7b\u4e0d\u80fd\u88ab\u7ee7\u627f,\u7528 final \u58f0\u660e\u7684\u65b9\u6cd5\u4e0d\u80fd\u88ab\u91cd\u5199,\u4f7f\u7528 final \u58f0\u660e\u7684\u53d8\u91cf\u5c31\u76f8\u5f53\u4e8e\u5e38\u91cf,\u4e0d\u80fd\u88ab\u4fee\u6539\u3002<\/p>\n<h4>4.final \u548c finally \u7684\u533a\u522b?<\/h4>\n<p>finally\u662f\u5728\u5f02\u5e38\u91cc\u7ecf\u5e38\u7528\u5230\u7684, \u5c31\u662f try \u548c cach \u91cc\u7684\u4ee3\u7801\u6267\u884c\u5b8c\u4ee5\u540e,\u5fc5\u987b\u8981\u6267\u884c\u7684\u65b9\u6cd5,\u6211\u4eec\u7ecf\u5e38\u5728 finally \u91cc\u5199\u4e00\u4e9b\u5173\u95ed\u8d44\u6e90\u7684\u65b9\u6cd5,\u6bd4\u5982\u8bf4\u5173\u95ed\u6570\u636e\u5e93\u8fde\u63a5,\u6216\u8005\u5173\u95ed IO \u6d41\u4ec0\u4e48\u7684.&#8211;&gt;<a href=\"https:\/\/199604.com\/1241\">Java\u81ea\u6211\u8fdb\u9636\u77e5\u8bc6\u6574\u74061\uff1a\u4f7f\u7528try-with-resources\u4f18\u96c5\u5173\u95ed\u8d44\u6e90<\/a><\/p>\n<h4>5.HashMap \u548c Hashtable \u7684\u533a\u522b<\/h4>\n<p>\u8fd9\u4e24\u4e2a\u90fd\u662f\u662f Map \u63a5\u53e3\u4e0b\u7684\u5b9e\u73b0\u7c7b\uff0c\u6211\u4eec\u5f00\u53d1\u7684\u65f6\u5019\u7ecf\u5e38\u7528\u7684\u662f HashMap \u867d\u7136 HashMap\u4e0d\u662f\u7ebf\u7a0b\u5b89\u5168\u7684\u4f46\u662f\u4ed6\u7684\u5b58\u50a8\u6548\u7387\u6bd4\u8f83\u9ad8,Hashtable \u662f\u7ebf\u7a0b\u5b89\u5168\u6211\u4eec\u770b\u8fc7\u4ed6\u5e95\u5c42\u7684 put \u65b9\u6cd5\u524d\u9762\u52a0\u7684 synchronized\u5173\u952e\u5b57,\u4f46\u662f\u4ed6\u7684\u6548\u7387\u592a\u4f4e,\u6211\u4eec\u5f00\u53d1\u5f88\u5c11\u7528.\u4e3a\u4ec0\u4e48\u8bf4 hashTable\u662f\u7ebf\u7a0b\u5b89\u5168\u7684? \u56e0\u4e3a\u770b\u6e90\u7801\u7684\u65f6\u5019\u91cc\u9762\u7684 put \u65b9\u6cd5\u524d\u9762\u52a0\u4e86 synchronized \u5173\u952e\u5b57,\u4ec0\u4e48\u60c5\u51b5\u4e0b\u7528 hashMap? \u6211\u4eec\u6709\u65f6\u5019\u5728\u81ea\u5b9a\u4e49\u8fd4\u56de json \u5b57\u7b26\u4e32\u7684\u65f6\u5019,\u5c01\u88c5\u5230 List \u4e2d\u8fdb\u884c\u8fd4\u56de.<\/p>\n<h4>6.int \u548c Integer \u7684\u533a\u522b\uff1f<\/h4>\n<p>Int \u662f\u57fa\u672c\u6570\u636e\u7c7b\u578b\u5440 Integer \u662f java \u4e3a int \u63d0\u4f9b\u7684\u5c01\u88c5\u7c7b\uff0c\u662f\u5f15\u7528\u6570\u636e\u7c7b\u578b\uff1b<br \/>\nInt \u7684\u9ed8\u8ba4\u503c\u4e3a 0\uff0c\u800c integer \u7684\u9ed8\u8ba4\u503c\u4e3a null<\/p>\n<h4>7.Java \u7684\u4e09\u5927\u7279\u6027<\/h4>\n<p>\u8fd9\u4e2a java \u7684\u4e09\u5927\u7279\u6027\u65e0\u975e\u5c31\u662f\u5c01\u88c5\uff0c\u7ee7\u627f\uff0c\u591a\u6001\u561b \u5c01\u88c5\u4f53\u73b0\u5230\u6211\u4eec\u628a\u65b9\u6cd5\u548c\u53d8\u91cf\u90fd\u5c01\u88c5\u5230\u4e00\u4e2a\u7c7b\u91cc,\u76f4\u63a5\u7528\u5bf9\u8c61\u8c03\u7528\u5c31\u53ef\u4ee5\u4e86<br \/>\n\u7ee7\u627f\u7684\u4f53\u73b0\u662f\u6211\u4eec\u53ef\u4ee5\u590d\u7528\u7236\u7c7b\u91cc\u7684\u4ee3\u7801,\u6211\u4eec\u5728\u9879\u76ee\u4e2d\u53ef\u4ee5\u628a\u516c\u6709\u7684\u65b9\u6cd5\u5199\u5230 base \u7684\u4e00\u4e2a\u7c7b\u4e2d,\u8ba9\u5176\u4ed6\u7c7b\u7ee7\u627f\u5c31\u53ef\u4ee5\u4e86. \u591a\u6001\u5c31\u662f Java \u91cc\u7684\u7ee7\u627f\uff0c\u91cd\u5199\uff0c\u91cd\u8f7d,\u90fd\u662f\u591a\u6001,\u5982\u679c\u4e24\u8fb9\u662f\u6570\u5b57\u7684\u5316,\u90a3\u5c31\u662f\u4e00 \u4e2a\u8fd0\u7b97\u7b26,\u5982\u679c\u4e24\u8fb9\u662f\u5b57\u7b26\u4e32\u7684\u8bdd,\u90a3\u4ed6\u5c31\u662f\u4e2a\u8fde\u63a5\u7b26.<\/p>\n<h4>8.ArrayList \u4e0e LinkedList \u533a\u522b<\/h4>\n<p>ArrayList \u4f7f\u7528\u6570\u7ec4\u65b9\u5f0f\u5b58\u50a8\u6570\u636e\uff0c\u6240\u4ee5\u6839\u636e\u7d22\u5f15\u67e5\u8be2\u6570\u636e\u901f\u5ea6\u5feb\uff0c\u800c\u65b0\u589e\u6216\u8005\u5220\u9664\u5143\u7d20\u65f6\u9700\u8981\u8bbe\u8ba1\u5230\u4f4d\u79fb\u64cd\u4f5c\uff0c\u6240\u4ee5\u6bd4\u8f83\u6162\u3002<br \/>\nLinkedList \u4f7f\u7528\u53cc\u5411\u94fe\u63a5\u65b9\u5f0f\u5b58\u50a8\u6570\u636e\uff0c\u6bcf\u4e2a\u5143\u7d20\u90fd\u8bb0\u5f55\u524d\u540e\u5143\u7d20\u7684\u6307\u9488\uff0c\u6240\u4ee5\u63d2\u5165\u3001\u5220\u9664\u6570\u636e\u65f6\u53ea\u662f\u66f4\u6539\u524d\u540e\u5143\u7d20\u7684\u6307\u9488\u6307\u5411\u5373\u53ef\uff0c\u901f\u5ea6\u975e\u5e38\u5feb\uff0c\u7136\u540e\u901a\u8fc7\u4e0b\u6807\u67e5\u8be2\u5143\u7d20\u65f6\u9700\u8981\u4ece\u5934\u5f00\u59cb\u7d22\u5f15\uff0c\u6240\u4ee5\u6bd4\u8f83\u6162\uff0c\u4f46\u662f\u5982\u679c\u67e5\u8be2\u524d\u51e0\u4e2a\u5143\u7d20\u6216\u540e\u51e0\u4e2a\u5143\u7d20\u901f\u5ea6\u6bd4\u8f83\u5feb\u3002\u5f00\u53d1\u4e2d\u4ec0\u4e48\u65f6\u5019\u5230 ArrayList?,\u6211\u4eec\u5728\u505a\u67e5\u8be2\u7684\u65f6\u5019\u628a\u67e5\u8be2\u51fa\u6765\u7684\u6570\u636e\u7ecf\u5e38\u5b58\u5230 arraylist \u91cc.<\/p>\n<h4>9.\u5728 Java \u4e2d\u8981\u60f3\u5b9e\u73b0\u591a\u7ebf\u7a0b\u4ee3\u7801\u6709\u4e09\u79cd\u624b\u6bb5?<\/h4>\n<p>\u4e00\u79cd\u662f\u7ee7\u627f Thread \u7c7b<br \/>\n\u53e6\u4e00\u79cd\u5c31\u662f\u5b9e\u73b0 Runnable \u63a5\u53e3<br \/>\n\u6700\u540e\u4e00\u79cd\u5c31\u662f\u5b9e\u73b0 Callable \u63a5\u53e3(\u7b2c\u56db\u79cd\u4e5f\u662f\u5b9e\u73b0 callable \u63a5\u53e3\uff0c\u53ea\u4e0d\u8fc7\u6709\u8fd4\u56de\u503c\u800c\u5df2)<\/p>\n<h4>10.\u7ebf\u7a0b\u7684\u72b6\u6001<\/h4>\n<p>\u5176\u5b9e\u7ebf\u7a0b\u4e00\u822c\u5177\u6709\u4e94\u79cd\u72b6\u6001\uff0c\u5373\u521b\u5efa\u3001\u5c31\u7eea\u3001\u8fd0\u884c\u3001\u963b\u585e\u3001\u7ec8\u6b62\u3002\uff08\u8fd9\u4e2a\u53ef\u4ee5\u53bb\u627e\u4e00\u4e0b\u56fe\uff0c\u6709\u52a9\u4e8e\u7406\u89e3\uff09<\/p>\n<hr \/>\n<p><div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/199604.com\/wp-content\/uploads\/2020\/04\/zhifubao.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"318\" height=\"406\" class=\"alignnone size-full wp-image-1417\" data-original=\"https:\/\/199604.com\/wp-content\/uploads\/2020\/04\/zhifubao.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\"  sizes=\"auto, (max-width: 318px) 100vw, 318px\" \/><\/div> <div class='fancybox-wrapper lazyload-container-unload' data-fancybox='post-images' href='https:\/\/199604.com\/wp-content\/uploads\/2020\/04\/weixin.png'><img class=\"lazyload lazyload-style-1\" src=\"data:image\/svg+xml;base64,PCEtLUFyZ29uTG9hZGluZy0tPgo8c3ZnIHdpZHRoPSIxIiBoZWlnaHQ9IjEiIHhtbG5zPSJodHRwOi8vd3d3LnczLm9yZy8yMDAwL3N2ZyIgc3Ryb2tlPSIjZmZmZmZmMDAiPjxnPjwvZz4KPC9zdmc+\"  loading=\"lazy\" decoding=\"async\" width=\"268\" height=\"291\" class=\"alignnone size-full wp-image-1416\" data-original=\"https:\/\/199604.com\/wp-content\/uploads\/2020\/04\/weixin.png\" src=\"data:image\/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAYAAAAfFcSJAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsQAAA7EAZUrDhsAAAANSURBVBhXYzh8+PB\/AAffA0nNPuCLAAAAAElFTkSuQmCC\" alt=\"\" \/><\/div><\/p>\n","protected":false},"excerpt":{"rendered":"<p>1.\u4ec0\u4e48\u662f\u91cd\u8f7d\u548c\u91cd\u5199\uff1f Java \u91cc\u65b9\u6cd5\u7684\u91cd\u5199(Overriding)\u548c\u91cd\u8f7d(Overloading)\u5c31\u662f\u6307\u7684 [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[130,2],"tags":[129],"class_list":["post-1387","post","type-post","status-publish","format-standard","hentry","category-java","category-2","tag-java"],"_links":{"self":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1387","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/comments?post=1387"}],"version-history":[{"count":1,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1387\/revisions"}],"predecessor-version":[{"id":1424,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/posts\/1387\/revisions\/1424"}],"wp:attachment":[{"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/media?parent=1387"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/categories?post=1387"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/199604.com\/wp-json\/wp\/v2\/tags?post=1387"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}