“`” \u8003\u70b9\uff1ajava\u57fa\u7840<\/p>\n
java\u4e3a\u6570\u636e\u7ed3\u6784\u4e2d\u7684\u6620\u5c04\u5b9a\u4e49\u4e86\u4e00\u4e2a\u63a5\u53e3java.util.Map;\u5b83\u6709\u56db\u4e2a\u5b9e\u73b0\u7c7b,\u5206\u522b\u662fHashMap Hashtable LinkedHashMap \u548cTreeMap.<\/p>\n
Map\u4e3b\u8981\u7528\u4e8e\u5b58\u50a8\u5065\u503c\u5bf9\uff0c\u6839\u636e\u952e\u5f97\u5230\u503c\uff0c\u56e0\u6b64\u4e0d\u5141\u8bb8\u952e\u91cd\u590d(\u91cd\u590d\u4e86\u8986\u76d6\u4e86),\u4f46\u5141\u8bb8\u503c\u91cd\u590d\u3002<\/p>\n
Hashmap \u662f\u4e00\u4e2a\u6700\u5e38\u7528\u7684Map,\u5b83\u6839\u636e\u952e\u7684HashCode\u503c\u5b58\u50a8\u6570\u636e,\u6839\u636e\u952e\u53ef\u4ee5\u76f4\u63a5\u83b7\u53d6\u5b83\u7684\u503c\uff0c\u5177\u6709\u5f88\u5feb\u7684\u8bbf\u95ee\u901f\u5ea6\uff0c\u904d\u5386\u65f6\uff0c\u53d6\u5f97\u6570\u636e\u7684\u987a\u5e8f\u662f\u5b8c\u5168\u968f\u673a\u7684\u3002 HashMap\u6700\u591a\u53ea\u5141\u8bb8\u4e00\u6761\u8bb0\u5f55\u7684\u952e\u4e3aNull;\u5141\u8bb8\u591a\u6761\u8bb0\u5f55\u7684\u503c\u4e3a Null;HashMap\u4e0d\u652f\u6301\u7ebf\u7a0b\u7684\u540c\u6b65\uff0c\u5373\u4efb\u4e00\u65f6\u523b\u53ef\u4ee5\u6709\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u5199HashMap;\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6570\u636e\u7684\u4e0d\u4e00\u81f4\u3002\u5982\u679c\u9700\u8981\u540c\u6b65\uff0c\u53ef\u4ee5\u7528 Collections\u7684synchronizedMap\u65b9\u6cd5\u4f7fHashMap\u5177\u6709\u540c\u6b65\u7684\u80fd\u529b\uff0c\u6216\u8005\u4f7f\u7528ConcurrentHashMap\u3002<\/p>\n
Hashtable\u4e0e HashMap\u7c7b\u4f3c,\u5b83\u7ee7\u627f\u81eaDictionary\u7c7b\uff0c\u4e0d\u540c\u7684\u662f:\u5b83\u4e0d\u5141\u8bb8\u8bb0\u5f55\u7684\u952e\u6216\u8005\u503c\u4e3a\u7a7a;\u5b83\u652f\u6301\u7ebf\u7a0b\u7684\u540c\u6b65\uff0c\u5373\u4efb\u4e00\u65f6\u523b\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u5199Hashtable,\u56e0\u6b64\u4e5f\u5bfc\u81f4\u4e86 Hashtable\u5728\u5199\u5165\u65f6\u4f1a\u6bd4\u8f83\u6162\u3002<\/p>\n
LinkedHashMap \u662fHashMap\u7684\u4e00\u4e2a\u5b50\u7c7b\uff0c\u4fdd\u5b58\u4e86\u8bb0\u5f55\u7684\u63d2\u5165\u987a\u5e8f\uff0c\u5728\u7528Iterator\u904d\u5386LinkedHashMap\u65f6\uff0c\u5148\u5f97\u5230\u7684\u8bb0\u5f55\u80af\u5b9a\u662f\u5148\u63d2\u5165\u7684.\u4e5f\u53ef\u4ee5\u5728\u6784\u9020\u65f6\u7528\u5e26\u53c2\u6570\uff0c\u6309\u7167\u5e94\u7528\u6b21\u6570\u6392\u5e8f\u3002\u5728\u904d\u5386\u7684\u65f6\u5019\u4f1a\u6bd4HashMap\u6162\uff0c\u4e0d\u8fc7\u6709\u79cd\u60c5\u51b5\u4f8b\u5916\uff0c\u5f53HashMap\u5bb9\u91cf\u5f88\u5927\uff0c\u5b9e\u9645\u6570\u636e\u8f83\u5c11\u65f6\uff0c\u904d\u5386\u8d77\u6765\u53ef\u80fd\u4f1a\u6bd4 LinkedHashMap\u6162\uff0c\u56e0\u4e3aLinkedHashMap\u7684\u904d\u5386\u901f\u5ea6\u53ea\u548c\u5b9e\u9645\u6570\u636e\u6709\u5173\uff0c\u548c\u5bb9\u91cf\u65e0\u5173\uff0c\u800cHashMap\u7684\u904d\u5386\u901f\u5ea6\u548c\u4ed6\u7684\u5bb9\u91cf\u6709\u5173\u3002<\/p>\n
TreeMap\u5b9e\u73b0SortMap\u63a5\u53e3\uff0c\u80fd\u591f\u628a\u5b83\u4fdd\u5b58\u7684\u8bb0\u5f55\u6839\u636e\u952e\u6392\u5e8f,\u9ed8\u8ba4\u662f\u6309\u952e\u503c\u7684\u5347\u5e8f\u6392\u5e8f\uff0c\u4e5f\u53ef\u4ee5\u6307\u5b9a\u6392\u5e8f\u7684\u6bd4\u8f83\u5668\uff0c\u5f53\u7528Iterator \u904d\u5386TreeMap\u65f6\uff0c\u5f97\u5230\u7684\u8bb0\u5f55\u662f\u6392\u8fc7\u5e8f\u7684\u3002<\/p>\n
\u4e00\u822c\u60c5\u51b5\u4e0b\uff0c\u6211\u4eec\u7528\u7684\u6700\u591a\u7684\u662fHashMap,\u5728Map \u4e2d\u63d2\u5165\u3001\u5220\u9664\u548c\u5b9a\u4f4d\u5143\u7d20\uff0cHashMap \u662f\u6700\u597d\u7684\u9009\u62e9\u3002\u4f46\u5982\u679c\u60a8\u8981\u6309\u81ea\u7136\u987a\u5e8f\u6216\u81ea\u5b9a\u4e49\u987a\u5e8f\u904d\u5386\u952e\uff0c\u90a3\u4e48TreeMap\u4f1a\u66f4\u597d\u3002\u5982\u679c\u9700\u8981\u8f93\u51fa\u7684\u987a\u5e8f\u548c\u8f93\u5165\u7684\u76f8\u540c,\u90a3\u4e48\u7528LinkedHashMap \u53ef\u4ee5\u5b9e\u73b0,\u5b83\u8fd8\u53ef\u4ee5\u6309\u8bfb\u53d6\u987a\u5e8f\u6765\u6392\u5217.<\/p>\n
HashMap\u662f\u4e00\u4e2a\u6700\u5e38\u7528\u7684Map\uff0c\u5b83\u6839\u636e\u952e\u7684hashCode\u503c\u5b58\u50a8\u6570\u636e\uff0c\u6839\u636e\u952e\u53ef\u4ee5\u76f4\u63a5\u83b7\u53d6\u5b83\u7684\u503c\uff0c\u5177\u6709\u5f88\u5feb\u7684\u8bbf\u95ee\u901f\u5ea6\u3002HashMap\u6700\u591a\u53ea\u5141\u8bb8\u4e00\u6761\u8bb0\u5f55\u7684\u952e\u4e3aNULL\uff0c\u5141\u8bb8\u591a\u6761\u8bb0\u5f55\u7684\u503c\u4e3aNULL\u3002<\/p>\n
HashMap\u4e0d\u652f\u6301\u7ebf\u7a0b\u540c\u6b65\uff0c\u5373\u4efb\u4e00\u65f6\u523b\u53ef\u4ee5\u6709\u591a\u4e2a\u7ebf\u7a0b\u540c\u65f6\u5199HashMap\uff0c\u53ef\u80fd\u4f1a\u5bfc\u81f4\u6570\u636e\u7684\u4e0d\u4e00\u81f4\u6027\u3002\u5982\u679c\u9700\u8981\u540c\u6b65\uff0c\u53ef\u4ee5\u7528Collections\u7684synchronizedMap\u65b9\u6cd5\u4f7fHashMap\u5177\u6709\u540c\u6b65\u7684\u80fd\u529b\u3002<\/p>\n
Hashtable\u4e0eHashMap\u7c7b\u4f3c\uff0c\u4e0d\u540c\u7684\u662f\uff1a\u5b83\u4e0d\u5141\u8bb8\u8bb0\u5f55\u7684\u952e\u6216\u8005\u503c\u4e3a\u7a7a\uff1b\u5b83\u652f\u6301\u7ebf\u7a0b\u7684\u540c\u6b65\uff0c\u5373\u4efb\u4e00\u65f6\u523b\u53ea\u6709\u4e00\u4e2a\u7ebf\u7a0b\u80fd\u5199Hashtable\uff0c\u56e0\u6b64\u4e5f\u5bfc\u81f4\u4e86Hashtable\u5728\u5199\u5165\u65f6\u4f1a\u6bd4\u8f83\u6162\u3002<\/p>\n
LinkedHashMap\u4fdd\u5b58\u4e86\u8bb0\u5f55\u7684\u63d2\u5165\u987a\u5e8f\uff0c\u5728\u7528Iterator\u904d\u5386LinkedHashMap\u65f6\uff0c\u5148\u5f97\u5230\u7684\u8bb0\u5f55\u80af\u5b9a\u662f\u5148\u63d2\u5165\u7684\u3002<\/p>\n
\u5728\u904d\u5386\u7684\u65f6\u5019\u4f1a\u6bd4HashMap\u6162TreeMap\u80fd\u591f\u628a\u5b83\u4fdd\u5b58\u7684\u8bb0\u5f55\u6839\u636e\u952e\u6392\u5e8f\uff0c\u9ed8\u8ba4\u662f\u6309\u5347\u5e8f\u6392\u5e8f\uff0c\u4e5f\u53ef\u4ee5\u6307\u5b9a\u6392\u5e8f\u7684\u6bd4\u8f83\u5668\u3002\u5f53\u7528Iterator\u904d\u5386TreeMap\u65f6\uff0c\u5f97\u5230\u7684\u8bb0\u5f55\u662f\u6392\u8fc7\u5e8f\u7684\u3002<\/p>\n
\u00a0<\/p>\n
<pre><code> "“`
\n<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"
“`” \u8003\u70b9\uff1ajava\u57fa\u7840 java\u4e3a\u6570\u636e\u7ed3\u6784\u4e2d\u7684\u6620\u5c04\u5b9a\u4e49\u4e86\u4e00\u4e2a\u63a5\u53e3java.util […]<\/p>\n","protected":false},"author":7,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[101],"tags":[],"class_list":["post-38922","post","type-post","status-publish","format-standard","hentry","category-c"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/38922","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\/7"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=38922"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/38922\/revisions"}],"predecessor-version":[{"id":38923,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/38922\/revisions\/38923"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=38922"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=38922"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=38922"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}