{"id":593,"date":"2015-06-27T18:40:34","date_gmt":"2015-06-27T10:40:34","guid":{"rendered":"http:\/\/www.dongchangbin.net.cn\/?p=593"},"modified":"2015-06-27T18:40:50","modified_gmt":"2015-06-27T10:40:50","slug":"linkedhashmap-%ef%bc%9a-%e8%ae%b0%e5%bd%95%e6%8f%92%e5%85%a5%e9%a1%ba%e5%ba%8f%e7%9a%84map","status":"publish","type":"post","link":"https:\/\/www.dongchangbin.net.cn\/?p=593","title":{"rendered":"LinkedHashMap \uff1a \u8bb0\u5f55\u63d2\u5165\u987a\u5e8f\u7684Map"},"content":{"rendered":"<p>\u4eca\u65e5\u505a\u4e00\u4e2a\u66f2\u7ebf\u56fe\uff0c\u7528\u5230map\u5b58\u50a8\u6570\u636e\uff0c\u5f00\u59cb\u4e60\u60ef\u6027\u7684\u4f7f\u7528\u4e86hashmap\uff0c\u7ed3\u679c\u53d1\u73b0\u5728\u8ba1\u7b97\u51fa\u6765\u7ed3\u679c\u5c55\u73b0\u7684\u65f6\u5019\uff0c\u65e5\u671f\u5e76\u6ca1\u6709\u6309\u7167\u9884\u8ba1\u7684\u987a\u5e8f\u6392\u5217\u3002\u6bd4\u5982\uff0c\u7edf\u8ba1\u51fa\u6765\u7684\u6570\u636e\u662f20150626\u548c20150627\u4e24\u5929\u7684\uff0c\u771f\u6b63\u5728\u9875\u9762\u4e0a\u5c55\u73b0\u7684\u65f6\u5019\uff0c\u53cd\u800c\u662f20150626\u5728\u540e\u9762\u3002<br \/>\n\u7ecf\u8fc7\u4ed4\u7ec6\u89c2\u5bdf\uff0c\u53d1\u73b0\u6570\u636e\u5bf9\u5e94\u5e76\u6ca1\u6709\u9519\uff0c\u4e5f\u5c31\u662f\u8bf4\uff0c\u662f\u4e00\u5f00\u59cb\u7528\u6765\u5b58\u50a8\u4ee5\u5929\u4e3akey\u503c\u7684\u8282\u70b9\u6570\u636e\u7684\u65f6\u5019\u987a\u5e8f\u662f\u6df7\u4e71\u7684\uff0c\u5728\u904d\u5386\u7684\u65f6\u5019\u5e76\u6ca1\u6709\u6309\u7167\u5b58\u5165\u7684\u987a\u5e8f\u8fdb\u884c\u904d\u5386\u3002<\/p>\n<p>\u7531\u4e8e\u65e5\u671f\u4e0e\u6570\u636e\u7684\u5217\u8868\u65f6\u5206\u5f00\u5b58\u50a8\u7684\uff0c\u8ba1\u7b97\u5b8c\u6210\u4e4b\u540e\u518d\u6309\u7167\u65e5\u671f\u6392\u5e8f\u7684\u65b9\u6cd5\u4e0d\u53ef\u53d6\u3002\u5370\u8c61\u91cclinkedhashmap\u548ctreemap\u662f\u6709\u987a\u5e8f\u7684\uff0c\u4ece\u7f51\u4e0a\u627e\u8d44\u6599\u786e\u8ba4\u4e00\u4e0b\uff0c\u53d1\u73b0\uff0clinkedhashmap\u662f\u53ef\u4ee5\u4fdd\u7559\u5b58\u5165\u7684\u5143\u7d20\u7684\u987a\u5e8f\u7684\uff0c\u904d\u5386\u7684\u65f6\u5019\u662f\u6309\u7167\u5b58\u5165\u7684\u987a\u5e8f\u904d\u5386\uff0c\u8fd9\u4e2a\u7b26\u5408\u6211\u7684\u8981\u6c42\u3002treemap\u662f\u6709\u4e2a\u987a\u5e8f\uff0c\u4e0d\u8fc7\u662f\u9ed8\u8ba4\u6309\u7167key\u503c\u8fdb\u884c\u6392\u5e8f\uff0c\u800c\u975e\u5b58\u50a8\u65f6\u5019\u7684\u987a\u5e8f\u3002\u4f46\u7531\u4e8e\u6211\u5728\u83b7\u53d6\u6570\u636e\u5217\u8868\u7684\u65f6\u5019\u5df2\u7ecf\u6309\u7167\u65f6\u95f4\u6392\u5e8f\uff0c\u4e0d\u9700\u8981\u518d\u6b21\u8fdb\u884c\u6392\u5e8f\uff0c\u56e0\u6b64\u6ca1\u6709\u9009\u62e9\u7528treemap\u3002<\/p>\n<p>LinkedHashMap\u7684\u5b9e\u73b0\u6574\u7406\u5982\u4e0b\uff1a<\/p>\n<p>\u53c2\u8003\u6587\u6863\u5730\u5740\u300ahttp:\/\/www.cnblogs.com\/children\/archive\/2012\/10\/02\/2710624.html\u300b<\/p>\n<p><img decoding=\"async\" src=\"http:\/\/dl.iteye.com\/upload\/attachment\/0067\/9070\/f1a24960-6587-38b7-9af0-d0e2cbc1530d.jpg\" alt=\"\" \/><\/p>\n<p>1. LinkedHashMap\u6982\u8ff0\uff1a<\/p>\n<p>LinkedHashMap\u662fHashMap\u7684\u4e00\u4e2a\u5b50\u7c7b\uff0c\u5b83<strong>\u4fdd\u7559\u63d2\u5165\u7684\u987a\u5e8f<\/strong>\uff0c\u5982\u679c\u9700\u8981\u8f93\u51fa\u7684\u987a\u5e8f\u548c\u8f93\u5165\u65f6\u7684\u76f8\u540c\uff0c\u90a3\u4e48\u5c31\u9009\u7528LinkedHashMap\u3002<\/p>\n<p>LinkedHashMap\u662fMap\u63a5\u53e3\u7684\u54c8\u5e0c\u8868\u548c\u94fe\u63a5\u5217\u8868\u5b9e\u73b0\uff0c\u5177\u6709\u53ef\u9884\u77e5\u7684\u8fed\u4ee3\u987a\u5e8f\u3002\u6b64\u5b9e\u73b0\u63d0\u4f9b\u6240\u6709\u53ef\u9009\u7684\u6620\u5c04\u64cd\u4f5c\uff0c\u5e76<strong>\u5141\u8bb8\u4f7f\u7528null\u503c\u548cnull\u952e<\/strong>\u3002\u6b64\u7c7b\u4e0d\u4fdd\u8bc1\u6620\u5c04\u7684\u987a\u5e8f\uff0c\u7279\u522b\u662f\u5b83<strong>\u4e0d\u4fdd\u8bc1\u8be5\u987a\u5e8f\u6052\u4e45\u4e0d\u53d8<\/strong>\u3002<br \/>\nLinkedHashMap\u5b9e\u73b0\u4e0eHashMap\u7684\u4e0d\u540c\u4e4b\u5904\u5728\u4e8e\uff0c\u540e\u8005\u7ef4\u62a4\u7740\u4e00\u4e2a\u8fd0\u884c\u4e8e\u6240\u6709\u6761\u76ee\u7684\u53cc\u91cd\u94fe\u63a5\u5217\u8868\u3002\u6b64\u94fe\u63a5\u5217\u8868\u5b9a\u4e49\u4e86\u8fed\u4ee3\u987a\u5e8f\uff0c\u8be5\u8fed\u4ee3\u987a\u5e8f\u53ef\u4ee5\u662f\u63d2\u5165\u987a\u5e8f\u6216\u8005\u662f\u8bbf\u95ee\u987a\u5e8f\u3002<br \/>\n\u6ce8\u610f\uff0c\u6b64\u5b9e\u73b0\u4e0d\u662f\u540c\u6b65\u7684\u3002\u5982\u679c\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u8bbf\u95ee\u94fe\u63a5\u7684\u54c8\u5e0c\u6620\u5c04\uff0c\u800c\u5176\u4e2d\u81f3\u5c11\u4e00\u4e2a\u7ebf\u7a0b\u4ece\u7ed3\u6784\u4e0a\u4fee\u6539\u4e86\u8be5\u6620\u5c04\uff0c\u5219\u5b83\u5fc5\u987b\u4fdd\u6301\u5916\u90e8\u540c\u6b65\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u6839\u636e\u94fe\u8868\u4e2d\u5143\u7d20\u7684\u987a\u5e8f\u53ef\u4ee5\u5206\u4e3a\uff1a<strong>\u6309\u63d2\u5165\u987a\u5e8f\u7684\u94fe\u8868\uff0c\u548c\u6309\u8bbf\u95ee\u987a\u5e8f(\u8c03\u7528get\u65b9\u6cd5)\u7684\u94fe\u8868\u3002<\/strong><\/p>\n<p>\u9ed8\u8ba4\u662f\u6309\u63d2\u5165\u987a\u5e8f\u6392\u5e8f\uff0c\u5982\u679c\u6307\u5b9a\u6309\u8bbf\u95ee\u987a\u5e8f\u6392\u5e8f\uff0c\u90a3\u4e48\u8c03\u7528get\u65b9\u6cd5\u540e\uff0c\u4f1a\u5c06\u8fd9\u6b21\u8bbf\u95ee\u7684\u5143\u7d20\u79fb\u81f3\u94fe\u8868\u5c3e\u90e8\uff0c\u4e0d\u65ad\u8bbf\u95ee\u53ef\u4ee5\u5f62\u6210\u6309\u8bbf\u95ee\u987a\u5e8f\u6392\u5e8f\u7684\u94fe\u8868\u3002 \u00a0\u53ef\u4ee5\u91cd\u5199removeEldestEntry\u65b9\u6cd5\u8fd4\u56detrue\u503c\u6307\u5b9a\u63d2\u5165\u5143\u7d20\u65f6\u79fb\u9664\u6700\u8001\u7684\u5143\u7d20\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>2. LinkedHashMap\u7684\u5b9e\u73b0\uff1a<\/p>\n<p>\u5bf9\u4e8eLinkedHashMap\u800c\u8a00\uff0c\u5b83\u7ee7\u627f\u4e0eHashMap\u3001\u5e95\u5c42\u4f7f\u7528\u54c8\u5e0c\u8868\u4e0e\u53cc\u5411\u94fe\u8868\u6765\u4fdd\u5b58\u6240\u6709\u5143\u7d20\u3002\u5176\u57fa\u672c\u64cd\u4f5c\u4e0e\u7236\u7c7bHashMap\u76f8\u4f3c\uff0c\u5b83\u901a\u8fc7\u91cd\u5199\u7236\u7c7b\u76f8\u5173\u7684\u65b9\u6cd5\uff0c\u6765\u5b9e\u73b0\u81ea\u5df1\u7684\u94fe\u63a5\u5217\u8868\u7279\u6027\u3002\u4e0b\u9762\u6211\u4eec\u6765\u5206\u6790LinkedHashMap\u7684\u6e90\u4ee3\u7801\uff1a<\/p>\n<p><strong>\u7c7b\u7ed3\u6784\uff1a<\/strong><\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"keyword\">public<\/span>\u00a0<span class=\"keyword\">class<\/span>\u00a0LinkedHashMap&lt;K,\u00a0V&gt;\u00a0<span class=\"keyword\">extends<\/span>\u00a0HashMap&lt;K,\u00a0V&gt;\u00a0<span class=\"keyword\">implements<\/span>\u00a0Map&lt;K,\u00a0V&gt;<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<p>1) \u6210\u5458\u53d8\u91cf\uff1a<\/p>\n<p>LinkedHashMap\u91c7\u7528\u7684hash\u7b97\u6cd5\u548cHashMap\u76f8\u540c\uff0c\u4f46\u662f\u5b83\u91cd\u65b0\u5b9a\u4e49\u4e86\u6570\u7ec4\u4e2d\u4fdd\u5b58\u7684\u5143\u7d20Entry\uff0c\u8be5Entry\u9664\u4e86\u4fdd\u5b58\u5f53\u524d\u5bf9\u8c61\u7684\u5f15\u7528\u5916\uff0c\u8fd8\u4fdd\u5b58\u4e86\u5176\u4e0a\u4e00\u4e2a\u5143\u7d20before\u548c\u4e0b\u4e00\u4e2a\u5143\u7d20after\u7684\u5f15\u7528\uff0c\u4ece\u800c\u5728\u54c8\u5e0c\u8868\u7684\u57fa\u7840\u4e0a\u53c8\u6784\u6210\u4e86\u53cc\u5411\u94fe\u63a5\u5217\u8868\u3002\u770b\u6e90\u4ee3\u7801\uff1a<\/p>\n<p>&nbsp;<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"comment\">\/\/true\u8868\u793a\u6309\u7167\u8bbf\u95ee\u987a\u5e8f\u8fed\u4ee3\uff0cfalse\u65f6\u8868\u793a\u6309\u7167\u63d2\u5165\u987a\u5e8f<\/span><\/li>\n<li>\u00a0<span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">final<\/span>\u00a0<span class=\"keyword\">boolean<\/span>\u00a0accessOrder;<\/li>\n<\/ol>\n<\/div>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"comment\">\/**<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\u00a0\u53cc\u5411\u94fe\u8868\u7684\u8868\u5934\u5143\u7d20\u3002<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\/<\/span><\/li>\n<li><span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">transient<\/span>\u00a0Entry&lt;K,V&gt;\u00a0header;<\/li>\n<li><\/li>\n<li><span class=\"comment\">\/**<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\u00a0LinkedHashMap\u7684Entry\u5143\u7d20\u3002<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\u00a0\u7ee7\u627fHashMap\u7684Entry\u5143\u7d20\uff0c\u53c8\u4fdd\u5b58\u4e86\u5176\u4e0a\u4e00\u4e2a\u5143\u7d20before\u548c\u4e0b\u4e00\u4e2a\u5143\u7d20after\u7684\u5f15\u7528\u3002<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\/<\/span><\/li>\n<li><span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">static<\/span>\u00a0<span class=\"keyword\">class<\/span>\u00a0Entry&lt;K,V&gt;\u00a0<span class=\"keyword\">extends<\/span>\u00a0HashMap.Entry&lt;K,V&gt;\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0before,\u00a0after;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u2026\u2026<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>HashMap.Entry:<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"keyword\">static<\/span>\u00a0<span class=\"keyword\">class<\/span>\u00a0Entry&lt;K,V&gt;\u00a0<span class=\"keyword\">implements<\/span>\u00a0Map.Entry&lt;K,V&gt;\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">final<\/span>\u00a0K\u00a0key;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0V\u00a0value;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0next;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">final<\/span>\u00a0<span class=\"keyword\">int<\/span>\u00a0hash;<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Entry(<span class=\"keyword\">int<\/span>\u00a0h,\u00a0K\u00a0k,\u00a0V\u00a0v,\u00a0Entry&lt;K,V&gt;\u00a0n)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0value\u00a0=\u00a0v;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0next\u00a0=\u00a0n;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0key\u00a0=\u00a0k;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0hash\u00a0=\u00a0h;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<p>2) \u521d\u59cb\u5316\uff1a<\/p>\n<p>\u901a\u8fc7\u6e90\u4ee3\u7801\u53ef\u4ee5\u770b\u51fa\uff0c\u5728LinkedHashMap\u7684\u6784\u9020\u65b9\u6cd5\u4e2d\uff0c\u5b9e\u9645\u8c03\u7528\u4e86\u7236\u7c7bHashMap\u7684\u76f8\u5173\u6784\u9020\u65b9\u6cd5\u6765\u6784\u9020\u4e00\u4e2a\u5e95\u5c42\u5b58\u653e\u7684table\u6570\u7ec4\u3002\u5982\uff1a<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">public<\/span>\u00a0LinkedHashMap(<span class=\"keyword\">int<\/span>\u00a0initialCapacity,\u00a0<span class=\"keyword\">float<\/span>\u00a0loadFactor)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">super<\/span>(initialCapacity,\u00a0loadFactor);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0accessOrder\u00a0=\u00a0<span class=\"keyword\">false<\/span>;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>HashMap\u4e2d\u7684\u76f8\u5173\u6784\u9020\u65b9\u6cd5\uff1a<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">public<\/span>\u00a0HashMap(<span class=\"keyword\">int<\/span>\u00a0initialCapacity,\u00a0<span class=\"keyword\">float<\/span>\u00a0loadFactor)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(initialCapacity\u00a0&lt;\u00a0<span class=\"number\">0<\/span>)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">throw<\/span>\u00a0<span class=\"keyword\">new<\/span>\u00a0IllegalArgumentException(<span class=\"string\">&#8220;Illegal\u00a0initial\u00a0capacity:\u00a0&#8220;<\/span>\u00a0+<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0initialCapacity);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(initialCapacity\u00a0&gt;\u00a0MAXIMUM_CAPACITY)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0initialCapacity\u00a0=\u00a0MAXIMUM_CAPACITY;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(loadFactor\u00a0&lt;=\u00a0<span class=\"number\">0<\/span>\u00a0||\u00a0Float.isNaN(loadFactor))<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">throw<\/span>\u00a0<span class=\"keyword\">new<\/span>\u00a0IllegalArgumentException(<span class=\"string\">&#8220;Illegal\u00a0load\u00a0factor:\u00a0&#8220;<\/span>\u00a0+<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0loadFactor);<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0Find\u00a0a\u00a0power\u00a0of\u00a02\u00a0&gt;=\u00a0initialCapacity<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">int<\/span>\u00a0capacity\u00a0=\u00a0<span class=\"number\">1<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">while<\/span>\u00a0(capacity\u00a0&lt;\u00a0initialCapacity)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0capacity\u00a0&lt;&lt;=\u00a0<span class=\"number\">1<\/span>;<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">this<\/span>.loadFactor\u00a0=\u00a0loadFactor;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0threshold\u00a0=\u00a0(<span class=\"keyword\">int<\/span>)(capacity\u00a0*\u00a0loadFactor);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0table\u00a0=\u00a0<span class=\"keyword\">new<\/span>\u00a0Entry[capacity];<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0init();<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>\u6211\u4eec\u5df2\u7ecf\u77e5\u9053LinkedHashMap\u7684Entry\u5143\u7d20\u7ee7\u627fHashMap\u7684Entry\uff0c\u63d0\u4f9b\u4e86\u53cc\u5411\u94fe\u8868\u7684\u529f\u80fd\u3002\u5728\u4e0a\u8ff0HashMap\u7684\u6784\u9020\u5668\u4e2d\uff0c\u6700\u540e\u4f1a\u8c03\u7528init()\u65b9\u6cd5\uff0c\u8fdb\u884c\u76f8\u5173\u7684\u521d\u59cb\u5316\uff0c\u8fd9\u4e2a\u65b9\u6cd5\u5728HashMap\u7684\u5b9e\u73b0\u4e2d\u5e76\u65e0\u610f\u4e49\uff0c\u53ea\u662f\u63d0\u4f9b\u7ed9\u5b50\u7c7b\u5b9e\u73b0\u76f8\u5173\u7684\u521d\u59cb\u5316\u8c03\u7528\u3002<br \/>\nLinkedHashMap\u91cd\u5199\u4e86init()\u65b9\u6cd5\uff0c\u5728\u8c03\u7528\u7236\u7c7b\u7684\u6784\u9020\u65b9\u6cd5\u5b8c\u6210\u6784\u9020\u540e\uff0c\u8fdb\u4e00\u6b65\u5b9e\u73b0\u4e86\u5bf9\u5176\u5143\u7d20Entry\u7684\u521d\u59cb\u5316\u64cd\u4f5c\u3002<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">void<\/span>\u00a0init()\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0header\u00a0=\u00a0<span class=\"keyword\">new<\/span>\u00a0Entry&lt;K,V&gt;(-<span class=\"number\">1<\/span>,\u00a0<span class=\"keyword\">null<\/span>,\u00a0<span class=\"keyword\">null<\/span>,\u00a0<span class=\"keyword\">null<\/span>);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0header.before\u00a0=\u00a0header.after\u00a0=\u00a0header;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>3) \u5b58\u50a8\uff1a<\/p>\n<p>LinkedHashMap\u5e76\u672a\u91cd\u5199\u7236\u7c7bHashMap\u7684put\u65b9\u6cd5\uff0c\u800c\u662f\u91cd\u5199\u4e86\u7236\u7c7bHashMap\u7684put\u65b9\u6cd5\u8c03\u7528\u7684\u5b50\u65b9\u6cd5void recordAccess(HashMap m)\u00a0\u00a0 \uff0cvoid addEntry(int hash, K key, V value, int bucketIndex) \u548cvoid createEntry(int hash, K key, V value, int bucketIndex)\uff0c\u63d0\u4f9b\u4e86\u81ea\u5df1\u7279\u6709\u7684\u53cc\u5411\u94fe\u63a5\u5217\u8868\u7684\u5b9e\u73b0\u3002<\/p>\n<p><strong>HashMap.put:<\/strong><\/p>\n<p>&nbsp;<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"keyword\">public<\/span>\u00a0V\u00a0put(K\u00a0key,\u00a0V\u00a0value)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(key\u00a0==\u00a0<span class=\"keyword\">null<\/span>)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0putForNullKey(value);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">int<\/span>\u00a0hash\u00a0=\u00a0hash(key.hashCode());<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">int<\/span>\u00a0i\u00a0=\u00a0indexFor(hash,\u00a0table.length);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">for<\/span>\u00a0(Entry&lt;K,V&gt;\u00a0e\u00a0=\u00a0table[i];\u00a0e\u00a0!=\u00a0<span class=\"keyword\">null<\/span>;\u00a0e\u00a0=\u00a0e.next)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Object\u00a0k;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(e.hash\u00a0==\u00a0hash\u00a0&amp;&amp;\u00a0((k\u00a0=\u00a0e.key)\u00a0==\u00a0key\u00a0||\u00a0key.equals(k)))\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0V\u00a0oldValue\u00a0=\u00a0e.value;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e.value\u00a0=\u00a0value;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e.recordAccess(<span class=\"keyword\">this<\/span>);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0oldValue;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0modCount++;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0addEntry(hash,\u00a0key,\u00a0value,\u00a0i);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">null<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>\u91cd\u5199\u65b9\u6cd5\uff1a<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"keyword\">void<\/span>\u00a0recordAccess(HashMap&lt;K,V&gt;\u00a0m)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0LinkedHashMap&lt;K,V&gt;\u00a0lm\u00a0=\u00a0(LinkedHashMap&lt;K,V&gt;)m;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(lm.accessOrder)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lm.modCount++;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0remove();<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0addBefore(lm.header);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">void<\/span>\u00a0addEntry(<span class=\"keyword\">int<\/span>\u00a0hash,\u00a0K\u00a0key,\u00a0V\u00a0value,\u00a0<span class=\"keyword\">int<\/span>\u00a0bucketIndex)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u8c03\u7528create\u65b9\u6cd5\uff0c\u5c06\u65b0\u5143\u7d20\u4ee5\u53cc\u5411\u94fe\u8868\u7684\u7684\u5f62\u5f0f\u52a0\u5165\u5230\u6620\u5c04\u4e2d\u3002<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0createEntry(hash,\u00a0key,\u00a0value,\u00a0bucketIndex);<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u5220\u9664\u6700\u8fd1\u6700\u5c11\u4f7f\u7528\u5143\u7d20\u7684\u7b56\u7565\u5b9a\u4e49<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0eldest\u00a0=\u00a0header.after;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(removeEldestEntry(eldest))\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0removeEntryForKey(eldest.key);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0}\u00a0<span class=\"keyword\">else<\/span>\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(size\u00a0&gt;=\u00a0threshold)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0resize(<span class=\"number\">2<\/span>\u00a0*\u00a0table.length);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">void<\/span>\u00a0createEntry(<span class=\"keyword\">int<\/span>\u00a0hash,\u00a0K\u00a0key,\u00a0V\u00a0value,\u00a0<span class=\"keyword\">int<\/span>\u00a0bucketIndex)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0HashMap.Entry&lt;K,V&gt;\u00a0old\u00a0=\u00a0table[bucketIndex];<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0e\u00a0=\u00a0<span class=\"keyword\">new<\/span>\u00a0Entry&lt;K,V&gt;(hash,\u00a0key,\u00a0value,\u00a0old);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0table[bucketIndex]\u00a0=\u00a0e;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u8c03\u7528\u5143\u7d20\u7684addBrefore\u65b9\u6cd5\uff0c\u5c06\u5143\u7d20\u52a0\u5165\u5230\u54c8\u5e0c\u3001\u53cc\u5411\u94fe\u63a5\u5217\u8868\u3002<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0e.addBefore(header);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0size++;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">void<\/span>\u00a0addBefore(Entry&lt;K,V&gt;\u00a0existingEntry)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0after\u00a0\u00a0=\u00a0existingEntry;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0before\u00a0=\u00a0existingEntry.before;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0before.after\u00a0=\u00a0<span class=\"keyword\">this<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0after.before\u00a0=\u00a0<span class=\"keyword\">this<\/span>;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<p>4) \u8bfb\u53d6\uff1a<\/p>\n<p>LinkedHashMap\u91cd\u5199\u4e86\u7236\u7c7bHashMap\u7684get\u65b9\u6cd5\uff0c\u5b9e\u9645\u5728\u8c03\u7528\u7236\u7c7bgetEntry()\u65b9\u6cd5\u53d6\u5f97\u67e5\u627e\u7684\u5143\u7d20\u540e\uff0c\u518d\u5224\u65ad\u5f53\u6392\u5e8f\u6a21\u5f0faccessOrder\u4e3atrue\u65f6\uff0c\u8bb0\u5f55\u8bbf\u95ee\u987a\u5e8f\uff0c\u5c06\u6700\u65b0\u8bbf\u95ee\u7684\u5143\u7d20\u6dfb\u52a0\u5230\u53cc\u5411\u94fe\u8868\u7684\u8868\u5934\uff0c\u5e76\u4ece\u539f\u6765\u7684\u4f4d\u7f6e\u5220\u9664\u3002\u7531\u4e8e\u7684\u94fe\u8868\u7684\u589e\u52a0\u3001\u5220\u9664\u64cd\u4f5c\u662f\u5e38\u91cf\u7ea7\u7684\uff0c\u6545\u5e76\u4e0d\u4f1a\u5e26\u6765\u6027\u80fd\u7684\u635f\u5931\u3002<\/p>\n<p><strong>HashMap.containsValue:<\/strong><\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"keyword\">public<\/span>\u00a0<span class=\"keyword\">boolean<\/span>\u00a0containsValue(Object\u00a0value)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(value\u00a0==\u00a0<span class=\"keyword\">null<\/span>)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0containsNullValue();<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0Entry[]\u00a0tab\u00a0=\u00a0table;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">for<\/span>\u00a0(<span class=\"keyword\">int<\/span>\u00a0i\u00a0=\u00a0<span class=\"number\">0<\/span>;\u00a0i\u00a0&lt;\u00a0tab.length\u00a0;\u00a0i++)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">for<\/span>\u00a0(Entry\u00a0e\u00a0=\u00a0tab[i]\u00a0;\u00a0e\u00a0!=\u00a0<span class=\"keyword\">null<\/span>\u00a0;\u00a0e\u00a0=\u00a0e.next)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(value.equals(e.value))<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">true<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">false<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li>\u00a0<span class=\"comment\">\/*\u67e5\u627eMap\u4e2d\u662f\u5426\u5305\u542b\u7ed9\u5b9a\u7684value\uff0c\u8fd8\u662f\u8003\u8651\u5230\uff0cLinkedHashMap\u62e5\u6709\u7684\u53cc\u94fe\u8868\uff0c\u5728\u8fd9\u91ccOverride\u662f\u4e3a\u4e86\u63d0\u9ad8\u8fed\u4ee3\u7684\u6548\u7387\u3002<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\/<\/span><\/li>\n<li><span class=\"keyword\">public<\/span>\u00a0<span class=\"keyword\">boolean<\/span>\u00a0containsValue(Object\u00a0value)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0Overridden\u00a0to\u00a0take\u00a0advantage\u00a0of\u00a0faster\u00a0iterator<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(value==<span class=\"keyword\">null<\/span>)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">for<\/span>\u00a0(Entry\u00a0e\u00a0=\u00a0header.after;\u00a0e\u00a0!=\u00a0header;\u00a0e\u00a0=\u00a0e.after)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(e.value==<span class=\"keyword\">null<\/span>)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">true<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0<span class=\"keyword\">else<\/span>\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">for<\/span>\u00a0(Entry\u00a0e\u00a0=\u00a0header.after;\u00a0e\u00a0!=\u00a0header;\u00a0e\u00a0=\u00a0e.after)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(value.equals(e.value))<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">true<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">false<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"comment\">\/*\u8be5transfer()\u662fHashMap\u4e2d\u7684\u5b9e\u73b0\uff1a\u904d\u5386\u6574\u4e2a\u8868\u7684\u5404\u4e2a\u6876\u4f4d\uff0c\u7136\u540e\u5bf9\u6876\u8fdb\u884c\u904d\u5386\u5f97\u5230\u6bcf\u4e00\u4e2aEntry\uff0c\u91cd\u65b0hash\u5230newTable\u4e2d\uff0c<\/span><\/li>\n<li><span class=\"comment\">\u00a0\/\/\u653e\u5728\u8fd9\u91cc\u662f\u4e3a\u4e86\u548c\u4e0b\u9762LinkedHashMap\u91cd\u5199\u8be5\u6cd5\u7684\u6bd4\u8f83\uff0c<\/span><\/li>\n<li><span class=\"comment\">\u00a0void\u00a0transfer(Entry[]\u00a0newTable)\u00a0{<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Entry[]\u00a0src\u00a0=\u00a0table;<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0int\u00a0newCapacity\u00a0=\u00a0newTable.length;<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0for\u00a0(int\u00a0j\u00a0=\u00a00;\u00a0j\u00a0&lt;\u00a0src.length;\u00a0j++)\u00a0{<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0e\u00a0=\u00a0src[j];<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0if\u00a0(e\u00a0!=\u00a0null)\u00a0{<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0src[j]\u00a0=\u00a0null;<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0do\u00a0{<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0next\u00a0=\u00a0e.next;<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0int\u00a0i\u00a0=\u00a0indexFor(e.hash,\u00a0newCapacity);<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e.next\u00a0=\u00a0newTable[i];<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0newTable[i]\u00a0=\u00a0e;<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e\u00a0=\u00a0next;<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0while\u00a0(e\u00a0!=\u00a0null);<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0}<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\/<\/span><\/li>\n<li><\/li>\n<li>\u00a0<span class=\"comment\">\/**<\/span><\/li>\n<li><span class=\"comment\">\u00a0*transfer()\u65b9\u6cd5\u662f\u5176\u7236\u7c7bHashMap\u8c03\u7528resize()\u7684\u65f6\u5019\u8c03\u7528\u7684\u65b9\u6cd5\uff0c\u5b83\u7684\u4f5c\u7528\u662f\u8868\u6269\u5bb9\u540e\uff0c\u628a\u65e7\u8868\u4e2d\u7684key\u91cd\u65b0hash\u5230\u65b0\u7684\u8868\u4e2d\u3002<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\u8fd9\u91cc\u4ece\u5199\u4e86\u7236\u7c7bHashMap\u4e2d\u7684\u8be5\u65b9\u6cd5\uff0c\u662f\u56e0\u4e3a\u8003\u8651\u5230\uff0cLinkedHashMap\u62e5\u6709\u7684\u53cc\u94fe\u8868\uff0c\u5728\u8fd9\u91ccOverride\u662f\u4e3a\u4e86\u63d0\u9ad8\u8fed\u4ee3\u7684\u6548\u7387\u3002<\/span><\/li>\n<li><span class=\"comment\">\u00a0*\/<\/span><\/li>\n<li>\u00a0<span class=\"keyword\">void<\/span>\u00a0transfer(HashMap.Entry[]\u00a0newTable)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0<span class=\"keyword\">int<\/span>\u00a0newCapacity\u00a0=\u00a0newTable.length;<\/li>\n<li>\u00a0\u00a0\u00a0<span class=\"keyword\">for<\/span>\u00a0(Entry&lt;K,\u00a0V&gt;\u00a0e\u00a0=\u00a0header.after;\u00a0e\u00a0!=\u00a0header;\u00a0e\u00a0=\u00a0e.after)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">int<\/span>\u00a0index\u00a0=\u00a0indexFor(e.hash,\u00a0newCapacity);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0e.next\u00a0=\u00a0newTable[index];<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0newTable[index]\u00a0=\u00a0e;<\/li>\n<li>\u00a0\u00a0\u00a0}<\/li>\n<li>\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">public<\/span>\u00a0V\u00a0get(Object\u00a0key)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u8c03\u7528\u7236\u7c7bHashMap\u7684getEntry()\u65b9\u6cd5\uff0c\u53d6\u5f97\u8981\u67e5\u627e\u7684\u5143\u7d20\u3002<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0e\u00a0=\u00a0(Entry&lt;K,V&gt;)getEntry(key);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(e\u00a0==\u00a0<span class=\"keyword\">null<\/span>)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">null<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u8bb0\u5f55\u8bbf\u95ee\u987a\u5e8f\u3002<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0e.recordAccess(<span class=\"keyword\">this<\/span>);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0e.value;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">void<\/span>\u00a0recordAccess(HashMap&lt;K,V&gt;\u00a0m)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0LinkedHashMap&lt;K,V&gt;\u00a0lm\u00a0=\u00a0(LinkedHashMap&lt;K,V&gt;)m;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u5982\u679c\u5b9a\u4e49\u4e86LinkedHashMap\u7684\u8fed\u4ee3\u987a\u5e8f\u4e3a\u8bbf\u95ee\u987a\u5e8f\uff0c<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0\u5219\u5220\u9664\u4ee5\u524d\u4f4d\u7f6e\u4e0a\u7684\u5143\u7d20\uff0c\u5e76\u5c06\u6700\u65b0\u8bbf\u95ee\u7684\u5143\u7d20\u6dfb\u52a0\u5230\u94fe\u8868\u8868\u5934\u3002<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(lm.accessOrder)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0lm.modCount++;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0remove();<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0addBefore(lm.header);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"comment\">\/**<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0*\u00a0Removes\u00a0this\u00a0entry\u00a0from\u00a0the\u00a0linked\u00a0list.<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0*\/<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">void<\/span>\u00a0remove()\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0before.after\u00a0=\u00a0after;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0after.before\u00a0=\u00a0before;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div id=\"\" class=\"dp-highlighter\">\n<ol class=\"dp-j\" start=\"1\">\n<li><span class=\"comment\">\/**clear\u94fe\u8868\uff0c\u8bbe\u7f6eheader\u4e3a\u521d\u59cb\u72b6\u6001*\/<\/span><\/li>\n<li><span class=\"keyword\">public<\/span>\u00a0<span class=\"keyword\">void<\/span>\u00a0clear()\u00a0{<\/li>\n<li>\u00a0<span class=\"keyword\">super<\/span>.clear();<\/li>\n<li>\u00a0header.before\u00a0=\u00a0header.after\u00a0=\u00a0header;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>5) \u6392\u5e8f\u6a21\u5f0f\uff1a<\/p>\n<p>LinkedHashMap\u5b9a\u4e49\u4e86\u6392\u5e8f\u6a21\u5f0faccessOrder\uff0c\u8be5\u5c5e\u6027\u4e3aboolean\u578b\u53d8\u91cf\uff0c\u5bf9\u4e8e\u8bbf\u95ee\u987a\u5e8f\uff0c\u4e3atrue\uff1b\u5bf9\u4e8e\u63d2\u5165\u987a\u5e8f\uff0c\u5219\u4e3afalse\u3002<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">final<\/span>\u00a0<span class=\"keyword\">boolean<\/span>\u00a0accessOrder;<\/li>\n<\/ol>\n<\/div>\n<p>\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u4e0d\u5fc5\u6307\u5b9a\u6392\u5e8f\u6a21\u5f0f\uff0c\u5176\u8fed\u4ee3\u987a\u5e8f\u5373\u4e3a\u9ed8\u8ba4\u4e3a\u63d2\u5165\u987a\u5e8f\u3002\u770bLinkedHashMap\u7684\u6784\u9020\u65b9\u6cd5\uff0c\u5982\uff1a<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">public<\/span>\u00a0LinkedHashMap(<span class=\"keyword\">int<\/span>\u00a0initialCapacity,\u00a0<span class=\"keyword\">float<\/span>\u00a0loadFactor)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">super<\/span>(initialCapacity,\u00a0loadFactor);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0accessOrder\u00a0=\u00a0<span class=\"keyword\">false<\/span>;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>\u8fd9\u4e9b\u6784\u9020\u65b9\u6cd5\u90fd\u4f1a\u9ed8\u8ba4\u6307\u5b9a\u6392\u5e8f\u6a21\u5f0f\u4e3a\u63d2\u5165\u987a\u5e8f\u3002\u5982\u679c\u4f60\u60f3\u6784\u9020\u4e00\u4e2aLinkedHashMap\uff0c\u5e76\u6253\u7b97\u6309\u4ece\u8fd1\u671f\u8bbf\u95ee\u6700\u5c11\u5230\u8fd1\u671f\u8bbf\u95ee\u6700\u591a\u7684\u987a\u5e8f\uff08\u5373\u8bbf\u95ee\u987a\u5e8f\uff09\u6765\u4fdd\u5b58\u5143\u7d20\uff0c\u90a3\u4e48\u8bf7\u4f7f\u7528\u4e0b\u9762\u7684\u6784\u9020\u65b9\u6cd5\u6784\u9020LinkedHashMap\uff1a<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">public<\/span>\u00a0LinkedHashMap(<span class=\"keyword\">int<\/span>\u00a0initialCapacity,<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">float<\/span>\u00a0loadFactor,<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">boolean<\/span>\u00a0accessOrder)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">super<\/span>(initialCapacity,\u00a0loadFactor);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">this<\/span>.accessOrder\u00a0=\u00a0accessOrder;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>\u8be5\u54c8\u5e0c\u6620\u5c04\u7684\u8fed\u4ee3\u987a\u5e8f\u5c31\u662f\u6700\u540e\u8bbf\u95ee\u5176\u6761\u76ee\u7684\u987a\u5e8f\uff0c\u8fd9\u79cd\u6620\u5c04\u5f88\u9002\u5408\u6784\u5efaLRU\u7f13\u5b58\u3002LinkedHashMap\u63d0\u4f9b\u4e86removeEldestEntry(Map.Entry&lt;K,V&gt; eldest)\u65b9\u6cd5\u3002\u8be5\u65b9\u6cd5\u53ef\u4ee5\u63d0\u4f9b\u5728\u6bcf\u6b21\u6dfb\u52a0\u65b0\u6761\u76ee\u65f6\u79fb\u9664\u6700\u65e7\u6761\u76ee\u7684\u5b9e\u73b0\u7a0b\u5e8f\uff0c\u9ed8\u8ba4\u8fd4\u56defalse\uff0c\u8fd9\u6837\uff0c\u6b64\u6620\u5c04\u7684\u884c\u4e3a\u5c06\u7c7b\u4f3c\u4e8e\u6b63\u5e38\u6620\u5c04\uff0c\u5373\u6c38\u8fdc\u4e0d\u80fd\u79fb\u9664\u6700\u65e7\u7684\u5143\u7d20\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>\u5f53\u6709\u65b0\u5143\u7d20\u52a0\u5165Map\u7684\u65f6\u5019\u4f1a\u8c03\u7528Entry\u7684addEntry\u65b9\u6cd5\uff0c\u4f1a\u8c03\u7528removeEldestEntry\u65b9\u6cd5\uff0c\u8fd9\u91cc\u5c31\u662f\u5b9e\u73b0LRU\u5143\u7d20\u8fc7\u671f\u673a\u5236\u7684\u5730\u65b9\uff0c\u9ed8\u8ba4\u7684\u60c5\u51b5\u4e0bremoveEldestEntry\u65b9\u6cd5\u53ea\u8fd4\u56defalse\u8868\u793a\u5143\u7d20\u6c38\u8fdc\u4e0d\u8fc7\u671f\u3002<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li>\u00a0\u00a0<span class=\"comment\">\/**<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\u00a0This\u00a0override\u00a0alters\u00a0behavior\u00a0of\u00a0superclass\u00a0put\u00a0method.\u00a0It\u00a0causes\u00a0newly<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\u00a0allocated\u00a0entry\u00a0to\u00a0get\u00a0inserted\u00a0at\u00a0the\u00a0end\u00a0of\u00a0the\u00a0linked\u00a0list\u00a0and<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\u00a0removes\u00a0the\u00a0eldest\u00a0entry\u00a0if\u00a0appropriate.<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\/<\/span><\/li>\n<li>\u00a0\u00a0\u00a0<span class=\"keyword\">void<\/span>\u00a0addEntry(<span class=\"keyword\">int<\/span>\u00a0hash,\u00a0K\u00a0key,\u00a0V\u00a0value,\u00a0<span class=\"keyword\">int<\/span>\u00a0bucketIndex)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0createEntry(hash,\u00a0key,\u00a0value,\u00a0bucketIndex);<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"comment\">\/\/\u00a0Remove\u00a0eldest\u00a0entry\u00a0if\u00a0instructed,\u00a0else\u00a0grow\u00a0capacity\u00a0if\u00a0appropriate<\/span><\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0Entry&lt;K,V&gt;\u00a0eldest\u00a0=\u00a0header.after;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(removeEldestEntry(eldest))\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0removeEntryForKey(eldest.key);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}\u00a0<span class=\"keyword\">else<\/span>\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">if<\/span>\u00a0(size\u00a0&gt;=\u00a0threshold)<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0resize(<span class=\"number\">2<\/span>\u00a0*\u00a0table.length);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0}<\/li>\n<li>\u00a0\u00a0\u00a0}<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0<span class=\"comment\">\/**<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\u00a0This\u00a0override\u00a0differs\u00a0from\u00a0addEntry\u00a0in\u00a0that\u00a0it\u00a0doesn&#8217;t\u00a0resize\u00a0the<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\u00a0table\u00a0or\u00a0remove\u00a0the\u00a0eldest\u00a0entry.<\/span><\/li>\n<li><span class=\"comment\">\u00a0\u00a0\u00a0\u00a0*\/<\/span><\/li>\n<li>\u00a0\u00a0\u00a0<span class=\"keyword\">void<\/span>\u00a0createEntry(<span class=\"keyword\">int<\/span>\u00a0hash,\u00a0K\u00a0key,\u00a0V\u00a0value,\u00a0<span class=\"keyword\">int<\/span>\u00a0bucketIndex)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0HashMap.Entry&lt;K,V&gt;\u00a0old\u00a0=\u00a0table[bucketIndex];<\/li>\n<li>Entry&lt;K,V&gt;\u00a0e\u00a0=\u00a0<span class=\"keyword\">new<\/span>\u00a0Entry&lt;K,V&gt;(hash,\u00a0key,\u00a0value,\u00a0old);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0table[bucketIndex]\u00a0=\u00a0e;<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0e.addBefore(header);<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0size++;<\/li>\n<li>\u00a0\u00a0\u00a0}<\/li>\n<li><\/li>\n<li>\u00a0\u00a0\u00a0<span class=\"keyword\">protected<\/span>\u00a0<span class=\"keyword\">boolean<\/span>\u00a0removeEldestEntry(Map.Entry&lt;K,V&gt;\u00a0eldest)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0<span class=\"keyword\">false<\/span>;<\/li>\n<li>\u00a0\u00a0\u00a0}<\/li>\n<\/ol>\n<\/div>\n<p>\u6b64\u65b9\u6cd5\u901a\u5e38\u4e0d\u4ee5\u4efb\u4f55\u65b9\u5f0f\u4fee\u6539\u6620\u5c04\uff0c\u76f8\u53cd\u5141\u8bb8\u6620\u5c04\u5728\u5176\u8fd4\u56de\u503c\u7684\u6307\u5f15\u4e0b\u8fdb\u884c\u81ea\u6211\u4fee\u6539\u3002\u5982\u679c\u7528\u6b64\u6620\u5c04\u6784\u5efaLRU\u7f13\u5b58\uff0c\u5219\u975e\u5e38\u65b9\u4fbf\uff0c\u5b83\u5141\u8bb8\u6620\u5c04\u901a\u8fc7\u5220\u9664\u65e7\u6761\u76ee\u6765\u51cf\u5c11\u5185\u5b58\u635f\u8017\u3002<\/p>\n<p>\u4f8b\u5982\uff1a\u91cd\u5199\u6b64\u65b9\u6cd5\uff0c\u7ef4\u6301\u6b64\u6620\u5c04\u53ea\u4fdd\u5b58100\u4e2a\u6761\u76ee\u7684\u7a33\u5b9a\u72b6\u6001\uff0c\u5728\u6bcf\u6b21\u6dfb\u52a0\u65b0\u6761\u76ee\u65f6\u5220\u9664\u6700\u65e7\u7684\u6761\u76ee\u3002<\/p>\n<div class=\"dp-highlighter\">\n<ol class=\"dp-j\">\n<li><span class=\"keyword\">private<\/span>\u00a0<span class=\"keyword\">static<\/span>\u00a0<span class=\"keyword\">final<\/span>\u00a0<span class=\"keyword\">int<\/span>\u00a0MAX_ENTRIES\u00a0=\u00a0<span class=\"number\">100<\/span>;<\/li>\n<li><span class=\"keyword\">protected<\/span>\u00a0<span class=\"keyword\">boolean<\/span>\u00a0removeEldestEntry(Map.Entry\u00a0eldest)\u00a0{<\/li>\n<li>\u00a0\u00a0\u00a0\u00a0<span class=\"keyword\">return<\/span>\u00a0size()\u00a0&gt;\u00a0MAX_ENTRIES;<\/li>\n<li>}<\/li>\n<\/ol>\n<\/div>\n<p>\u6765\u6e90\uff1a<a href=\"http:\/\/zhangshixi.iteye.com\/blog\/673789\">http:\/\/zhangshixi.iteye.com\/blog\/673789<\/a><\/p>\n<p>\u53c2\u8003\uff1a<a href=\"http:\/\/hi.baidu.com\/yao1111yao\/blog\/item\/3043e2f5657191f07709d7bb.html\">http:\/\/hi.baidu.com\/yao1111yao\/blog\/item\/3043e2f5657191f07709d7bb.html<\/a><\/p>\n<p>\u90e8\u5206\u4fee\u6539\u3002<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>\u4f7f\u7528LinkedHashMap\u6784\u5efaLRU\u7684Cache<\/p>\n<p><a href=\"http:\/\/tomyz0223.iteye.com\/blog\/1035686\">http:\/\/tomyz0223.iteye.com\/blog\/1035686<\/a><\/p>\n<p>\u57fa\u4e8eLinkedHashMap\u5b9e\u73b0LRU\u7f13\u5b58\u8c03\u5ea6\u7b97\u6cd5\u539f\u7406\u53ca\u5e94\u7528<\/p>\n<p><a href=\"http:\/\/woming66.iteye.com\/blog\/1284326\">http:\/\/woming66.iteye.com\/blog\/1284326<\/a><\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<p>\u5176\u5b9eLinkedHashMap\u51e0\u4e4e\u548cHashMap\u4e00\u6837\uff0c\u4e0d\u540c\u7684\u662f\u5b83\u5b9a\u4e49\u4e86\u4e00\u4e2aEntry&lt;K,V&gt; header\uff0c\u8fd9\u4e2aheader\u4e0d\u662f\u653e\u5728Table\u91cc\uff0c\u5b83\u662f\u989d\u5916\u72ec\u7acb\u51fa\u6765\u7684\u3002LinkedHashMap\u901a\u8fc7\u7ee7\u627fhashMap\u4e2d\u7684Entry&lt;K,V&gt;,\u5e76\u6dfb\u52a0\u4e24\u4e2a\u5c5e\u6027Entry&lt;K,V&gt; \u00a0before,after,\u548cheader\u7ed3\u5408\u8d77\u6765\u7ec4\u6210\u4e00\u4e2a\u53cc\u5411\u94fe\u8868\uff0c\u6765\u5b9e\u73b0\u6309\u63d2\u5165\u987a\u5e8f\u6216\u8bbf\u95ee\u987a\u5e8f\u6392\u5e8f\u3002<\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u4eca\u65e5\u505a\u4e00\u4e2a\u66f2\u7ebf\u56fe\uff0c\u7528\u5230map\u5b58\u50a8\u6570\u636e\uff0c\u5f00\u59cb\u4e60\u60ef\u6027\u7684\u4f7f\u7528\u4e86hashmap\uff0c\u7ed3\u679c\u53d1\u73b0\u5728\u8ba1\u7b97\u51fa\u6765\u7ed3\u679c\u5c55\u73b0\u7684\u65f6\u5019\uff0c\u65e5\u671f [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"aside","meta":{"footnotes":""},"categories":[89],"tags":[],"class_list":["post-593","post","type-post","status-publish","format-aside","hentry","category-89","post_format-post-format-aside"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v24.1 - 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