{"id":10869,"date":"2023-11-28T21:45:50","date_gmt":"2023-11-28T13:45:50","guid":{"rendered":"https:\/\/wx.kaifamiao.info\/?p=10869"},"modified":"2023-11-28T21:46:20","modified_gmt":"2023-11-28T13:46:20","slug":"java-zhonghashmap-zaijdk17hejdk18zhong-you-na-xie","status":"publish","type":"post","link":"http:\/\/wx.kaifamiao.info\/index.php\/2023\/11\/28\/java-zhonghashmap-zaijdk17hejdk18zhong-you-na-xie\/","title":{"rendered":"Java\u4e2dHashMap\u5728JDK1.7\u548cJDK1.8\u4e2d\u6709\u54ea\u4e9b\u4e0d\u540c?"},"content":{"rendered":"<p>\u5728Java\u4e2d\uff0c\u4fdd\u5b58\u6570\u636e\u6709\u4e24\u79cd\u6bd4\u8f83\u7b80\u5355\u7684\u6570\u636e\u7ed3\u6784\uff1a\u6570\u7ec4\u548c\u94fe\u8868\u3002<\/p>\n<p>\u6570\u7ec4\u7684\u7279\u70b9\u662f\uff1a\u5bfb\u5740\u5bb9\u6613\uff0c\u63d2\u5165\u548c\u5220\u9664\u56f0\u96be\uff1b<\/p>\n<p>\u94fe\u8868\u7684\u7279\u70b9\u662f\uff1a\u5bfb\u5740\u56f0\u96be\uff0c\u4f46\u63d2\u5165\u548c\u5220\u9664\u5bb9\u6613\uff1b\u6240\u4ee5\u6211\u4eec\u5c06\u6570\u7ec4\u548c\u94fe\u8868\u7ed3\u5408\u5728\u4e00\u8d77\uff0c\u53d1\u6325\u4e24\u8005\u5404\u81ea\u7684\u4f18\u52bf\uff0c\u4f7f\u7528\u4e00\u79cd\u53eb\u505a\u62c9\u94fe\u6cd5\u7684\u65b9\u5f0f\u53ef\u4ee5\u89e3\u51b3\u54c8\u5e0c\u51b2\u7a81\u3002<\/p>\n<p>HashMap JDK1.8\u4e4b\u524d<\/p>\n<p>JDK1.8\u4e4b\u524d\u91c7\u7528\u7684\u662f\u62c9\u94fe\u6cd5\u3002<\/p>\n<p>\u62c9\u94fe\u6cd5\uff1a\u5c06\u94fe\u8868\u548c\u6570\u7ec4\u76f8\u7ed3\u5408\u3002\u4e5f\u5c31\u662f\u8bf4\u521b\u5efa\u4e00\u4e2a\u94fe\u8868\u6570\u7ec4\uff0c\u6570\u7ec4\u4e2d\u6bcf\u4e00\u683c\u5c31\u662f\u4e00\u4e2a\u94fe\u8868\u3002\u82e5\u9047\u5230\u54c8\u5e0c\u51b2\u7a81\uff0c\u5219\u5c06\u51b2\u7a81\u7684\u503c\u52a0\u5230\u94fe\u8868\u4e2d\u5373\u53ef\u3002<\/p>\n<p>HashMap JDK1.8\u4e4b\u540e<\/p>\n<p>\u76f8\u6bd4\u4e8e\u4e4b\u524d\u7684\u7248\u672c\uff0cJDK1.8\u5728\u89e3\u51b3\u54c8\u5e0c\u51b2\u7a81\u65f6\u6709\u4e86\u8f83\u5927\u7684\u53d8\u5316\uff0c\u5f53\u94fe\u8868\u957f\u5ea6\u5927\u4e8e\u9608\u503c\uff08\u9ed8\u8ba4\u4e3a8\uff09\u65f6\uff0c\u5c06\u94fe\u8868\u8f6c\u5316\u4e3a\u7ea2\u9ed1\u6811\uff0c\u4ee5\u51cf\u5c11\u641c\u7d22\u65f6\u95f4\u3002<\/p>\n<p>JDK1.7 VS JDK1.8 \u6bd4\u8f83<\/p>\n<p>JDK1.8\u4e3b\u8981\u89e3\u51b3\u6216\u4f18\u5316\u4e86\u4ee5\u4e0b\u95ee\u9898\uff1a<\/p>\n<p>1\u3001resize \u6269\u5bb9\u4f18\u5316<\/p>\n<p>2\u3001\u5f15\u5165\u4e86\u7ea2\u9ed1\u6811\uff0c\u76ee\u7684\u662f\u907f\u514d\u5355\u6761\u94fe\u8868\u8fc7\u957f\u800c\u5f71\u54cd\u67e5\u8be2\u6548\u7387\uff0c\u7ea2\u9ed1\u6811\u7b97\u6cd5\u8bf7\u53c2\u8003<\/p>\n<p>3\u3001\u89e3\u51b3\u4e86\u591a\u7ebf\u7a0b\u6b7b\u5faa\u73af\u95ee\u9898\uff0c\u4f46\u4ecd\u662f\u975e\u7ebf\u7a0b\u5b89\u5168\u7684\uff0c\u591a\u7ebf\u7a0b\u65f6\u53ef\u80fd\u4f1a\u9020\u6210\u6570\u636e\u4e22\u5931\u95ee\u9898\u3002<\/p>\n<table>\n<thead>\n<tr>\n<th>\u4e0d\u540c<\/th>\n<th>JDK1.7<\/th>\n<th>JDK1.8<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>\u5b58\u50a8\u7ed3\u6784<\/td>\n<td>\u6570\u7ec4+\u94fe\u8868<\/td>\n<td>\u6570\u7ec4+\u94fe\u8868+\u7ea2\u9ed1\u6811<\/td>\n<\/tr>\n<tr>\n<td>\u521d\u59cb\u5316\u65b9\u5f0f<\/td>\n<td>\u5355\u72ec\u51fd\u6570\uff1ainflateTable()<\/td>\n<td>\u76f4\u63a5\u96c6\u6210\u5230\u4e86\u6269\u5bb9\u51fd\u6570resize()<\/td>\n<\/tr>\n<tr>\n<td>hash\u503c\u8ba1\u7b97\u65b9\u5f0f<\/td>\n<td>\u6270\u52a8\u5904\u7406=9\u6b21\u6270\u52a8=4\u6b21\u4f4d\u8fd0\u7b97+5\u6b21\u5f02\u6216\u8fd0\u7b97<\/td>\n<td>\u6270\u52a8\u5904\u7406=2\u6b21\u6270\u52a8=1\u6b21\u4f4d\u8fd0\u7b97+1\u6b21\u5f02\u6216\u8fd0\u7b97<\/td>\n<\/tr>\n<tr>\n<td>\u5b58\u653e\u6570\u636e\u7684\u89c4\u5219<\/td>\n<td>\u65e0\u51b2\u7a81\u65f6\uff0c\u5b58\u653e\u6570\u7ec4\uff1b\u51b2\u7a81\u65f6\uff0c\u5b58\u653e\u94fe\u8868<\/td>\n<td>\u65e0\u51b2\u7a81\u65f6\uff0c\u5b58\u653e\u6570\u7ec4\uff1b\u51b2\u7a81&amp;\u94fe\u8868\u957f\u5ea6&lt;8\uff1a\u5b58\u653e\u5355\u94fe\u8868\uff1b\u51b2\u7a81&amp;\u94fe\u8868\u957f\u5ea6&gt;8\uff1a\u6811\u5316\u5e76\u5b58\u653e\u7ea2\u9ed1\u6811<\/td>\n<\/tr>\n<tr>\n<td>\u63d2\u5165\u6570\u636e\u65b9\u5f0f<\/td>\n<td>\u5934\u63d2\u6cd5(\u5148\u5c06\u539f\u4f4d\u7f6e\u7684\u6570\u636e\u79fb\u5230\u540e1\u4f4d\uff0c\u518d\u63d2\u5165\u6570\u636e\u5230\u8be5\u4f4d\u7f6e)<\/td>\n<td>\u5c3e\u63d2\u6cd5(\u76f4\u63a5\u63d2\u5165\u5230\u94fe\u8868\u5c3e\u90e8\/\u7ea2\u9ed1\u6811)<\/td>\n<\/tr>\n<tr>\n<td>\u6269\u5bb9\u540e\u5b58\u50a8\u4f4d\u7f6e\u7684\u8ba1\u7b97\u65b9\u5f0f<\/td>\n<td>\u5168\u90e8\u6309\u7167\u539f\u6765\u65b9\u6cd5\u8fdb\u884c\u8ba1\u7b97(\u5373hashCode -&gt;&gt; \u6270\u52a8\u51fd\u6570 -&gt;&gt; (h&amp;length-1))<\/td>\n<td>\u6309\u7167\u6269\u5bb9\u540e\u7684\u89c4\u5f8b\u8ba1\u7b97(\u5373\u6269\u5bb9\u540e\u7684\u4f4d\u7f6e = \u539f\u4f4d\u7f6e or \u539f\u4f4d\u7f6e + \u65e7\u5bb9\u91cf)<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n","protected":false},"excerpt":{"rendered":"<p>\u5728Java\u4e2d\uff0c\u4fdd\u5b58\u6570\u636e\u6709\u4e24\u79cd\u6bd4\u8f83\u7b80\u5355\u7684\u6570\u636e\u7ed3\u6784\uff1a\u6570\u7ec4\u548c\u94fe\u8868\u3002 \u6570\u7ec4\u7684\u7279\u70b9\u662f\uff1a\u5bfb\u5740\u5bb9\u6613\uff0c\u63d2\u5165\u548c\u5220\u9664\u56f0\u96be\uff1b \u94fe\u8868\u7684 [&hellip;]<\/p>\n","protected":false},"author":8,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[99],"tags":[],"class_list":["post-10869","post","type-post","status-publish","format-standard","hentry","category-javabase"],"_links":{"self":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10869","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\/8"}],"replies":[{"embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/comments?post=10869"}],"version-history":[{"count":1,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10869\/revisions"}],"predecessor-version":[{"id":10870,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/posts\/10869\/revisions\/10870"}],"wp:attachment":[{"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/media?parent=10869"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/categories?post=10869"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/wx.kaifamiao.info\/index.php\/wp-json\/wp\/v2\/tags?post=10869"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}