{"id":993,"date":"2018-09-17T19:06:49","date_gmt":"2018-09-17T10:06:49","guid":{"rendered":"https:\/\/chat-messenger.com\/?p=993"},"modified":"2019-06-30T18:44:15","modified_gmt":"2019-06-30T09:44:15","slug":"%e9%81%8b%e8%a1%8c%e6%99%82%e7%b8%bd%e5%85%a7%e5%ad%98%e7%a9%ba%e9%96%92%e5%85%a7%e5%ad%98","status":"publish","type":"post","link":"https:\/\/chat-messenger.com\/zh_tw\/blog\/java\/runtime-totalmemory-freememory","title":{"rendered":"\u53d6\u5f97 Java \u8a18\u61b6\u9ad4\u4f7f\u7528\u60c5\u6cc1"},"content":{"rendered":"<h2 class=\"common_title\"><a name=\"0\">Java <strong>\u8a18\u61b6<\/strong>\u53d6\u5f97\u4f7f\u7528\u6578\u64da <strong>Runtime.getRuntime().totalMemory, freeMemory<\/strong><\/a><\/h2>\n<p>\n<strong>Java <\/strong> \u6b64\u51fd\u6578\u50b3\u56de\u6709\u95dc\u865b\u64ec\u6a5f\u5668\u8a18\u61b6\u9ad4\u7684\u4fe1\u606f\uff0c\u5305\u62ec\u300c\u7e3d\u8a18\u61b6\u9ad4\u300d\u3001\u300c\u5df2\u4f7f\u7528\u8a18\u61b6\u9ad4\u300d\u548c\u300c\u6700\u5927\u53ef\u7528\u8a18\u61b6\u9ad4\u300d\u503c\u3002<br \/>\n\u5404\u9805\u8aaa\u660e\u5982\u4e0b\uff1a\n<\/p>\n<ul>\n<li><strong>\u5168\u90e8\u7684<\/strong>\u30fb\u30fb\u30fb<strong>Runtime.getRuntime().totalMemory()<\/strong>\u9019\u662f\u5206\u914d\u7d66 Java \u865b\u64ec\u6a5f\u5668\u7684\u8a18\u61b6\u9ad4\u91cf\u3002<\/li>\n<li><strong>\u4f7f\u7528\u91cf<\/strong>\u30fb\u30fb\u30fb<strong>Runtime.getRuntime().totalMemory()<\/strong>\u3000-\u3000<strong>Runtime.getRuntime().freeMemory()<\/strong>\u5b83\u8b8a\u6210\u4e86\uff0c<br \/>\n\u9019\u662f\u7576\u524d\u5df2\u5206\u914d\u5230\u8a18\u61b6\u9ad4\u4e2d\u7684\u7269\u4ef6\u7684\u8a18\u61b6\u9ad4\u4f7f\u7528\u60c5\u6cc1\u3002<\/li>\n<li><strong>\u6700\u5927\u53ef\u7528<\/strong>\u30fb\u30fb\u30fb<strong>Runtime.getRuntime().maxMemory()<\/strong>\u9019\u4ee3\u8868Java\u865b\u64ec\u6a5f\u5668\u5c07\u5617\u8a66\u4f7f\u7528\u7684\u6700\u5927\u8a18\u61b6\u9ad4\u91cf\u3002<br \/>\n\u5982\u679c\u8a18\u61b6\u9ad4\u4f7f\u7528\u91cf\u63a5\u8fd1\u7e3d\u91cf\uff0c\u4e14\u5783\u573e\u56de\u6536\u6a5f\u5236\u7121\u6cd5\u91cb\u653e\u5167\u5b58\uff0cJava \u865b\u64ec\u6a5f\u5c07\u64f4\u5c55\u5230\u5176\u300c\u6700\u5927\u53ef\u7528\u300d\u5bb9\u91cf\u3002<\/li>\n<\/ul>\n<h2 class=\"common_title\"><a name=\"1\">\u7bc4\u4f8b\u7a0b\u5f0f<\/a><\/h2>\n<pre class=\"sample_src\">\/**\r\n * Java \u4eee\u60f3\u30de\u30b7\u30f3\u306e\u30e1\u30e2\u30ea\u7dcf\u5bb9\u91cf\u3001\u4f7f\u7528\u91cf\u3001\r\n * \u4f7f\u7528\u3092\u8a66\u307f\u308b\u6700\u5927\u30e1\u30e2\u30ea\u5bb9\u91cf\u306e\u60c5\u5831\u3092\u8fd4\u3057\u307e\u3059\u3002\r\n * @return Java \u4eee\u60f3\u30de\u30b7\u30f3\u306e\u30e1\u30e2\u30ea\u60c5\u5831\r\n *\/\r\npublic static String getMemoryInfo() {\r\n    DecimalFormat f1 = new DecimalFormat(\"#,###KB\");\r\n    DecimalFormat f2 = new DecimalFormat(\"##.#\");\r\n    long free = Runtime.getRuntime().freeMemory() \/ 1024;\r\n    long total = Runtime.getRuntime().totalMemory() \/ 1024;\r\n    long max = Runtime.getRuntime().maxMemory() \/ 1024;\r\n    long used = total - free;\r\n    double ratio = (used * 100 \/ (double)total);\r\n    String info = \r\n    \"Java \u30e1\u30e2\u30ea\u60c5\u5831 : \u5408\u8a08=\" + f1.format(total) + \"\u3001\" +\r\n    \"\u4f7f\u7528\u91cf=\" + f1.format(used) + \" (\" + f2.format(ratio) + \"%)\u3001\" +\r\n    \"\u4f7f\u7528\u53ef\u80fd\u6700\u5927=\"+f1.format(max);\r\n    return info;\r\n}\r\n<\/pre>\n<p><script type=\"text\/javascript\" src=\"https:\/\/chat-messenger.com\/js\/common.js?dd12sssas2223\" charset=\"UTF-8\"><\/script><br \/>\n<script type=\"text\/javascript\"> writePR(); <\/script><\/p>\n<h2 class=\"common_title\"><a name=\"2\">\u57f7\u884c\u7d50\u679c 1<\/a><\/h2>\n<p>\u25c6\u7bc4\u4f8b<\/p>\n<pre class=\"sample_src\">public static void main(String[] args) { System.out.println(getMemoryInfo()); }\r\n<\/pre>\n<p>\u25c6\u8f38\u51fa\u7d50\u679c<\/p>\n<pre class=\"console\">Java\u8a18\u61b6\u9ad4\u8cc7\u8a0a\uff1a\u7e3d\u8a08 = 1,984KB\uff0c\u5df2\u4f7f\u7528 = 458KB (23.1%)\uff0c\u6700\u5927\u53ef\u7528 = 65,088KB\r\n<\/pre>\n<h2 class=\"common_title\"><a name=\"3\">\u57f7\u884c\u7d50\u679c 2<\/a><\/h2>\n<p>\u25c6\u7bc4\u4f8b<br \/>\n\u5617\u8a66\u66f4\u6539 Java \u5806\u5927\u5c0f\u4e26\u57f7\u884c\u7a0b\u5f0f\u3002<br \/>\n\u53ef\u4ee5\u4f7f\u7528 Java \u6307\u4ee4\u9078\u9805\u6307\u5b9a Java \u5806\u5927\u5c0f\u3002<\/p>\n<div class=\"point\">\njava -Xms64m -Xmx512m \u4e3b\u7a0b\u5e8f <\/p>\n<p>-Xms \u521d\u59cb\u5806\u5927\u5c0f<br \/>\n\u6307\u5b9aJava\u865b\u64ec\u6a5f\u5668\u7684\u521d\u59cb\u8a18\u61b6\u9ad4\u5206\u914d\u91cf\u3002\u9810\u8a2d\u503c\u70ba2MB\u3002<br \/>\n-Xmx \u6700\u5927\u5806\u758a\u5927\u5c0f<br \/>\n\u6307\u5b9a\u5206\u914d\u7d66 Java \u865b\u64ec\u6a5f\u5668\u7684\u6700\u5927\u8a18\u61b6\u9ad4\u91cf\u3002\u9810\u8a2d\u503c\u70ba 64MB\u3002\n<\/div>\n\n<pre class=\"sample_src\">public static void main(String[] args) { System.out.println(getMemoryInfo()); }\r\n<\/pre>\n<p>\u25c6\u8f38\u51fa\u7d50\u679c<\/p>\n<pre class=\"console\">Java\u8a18\u61b6\u9ad4\u8cc7\u8a0a\uff1a\u7e3d\u8a08 = 65,088KB\uff0c\u5df2\u4f7f\u7528 = 524KB (0.8%)\uff0c\u6700\u5927\u53ef\u7528 = 520,256KB\r\n<\/pre>\n<p>\u201c\u7e3d\u904b\u884c\u6642\u9593.getRuntime().totalMemory()\u201d<strong>-Xms<\/strong>\u6700\u5927\u53ef\u7528\u503c\u70ba Runtime.getRuntime().maxMemory()\u3002<strong>-Xmx<\/strong>\u6b64\u9023\u7d50\u6307\u5411[\u76f8\u95dc\u9801\u9762]\u3002<\/p>","protected":false},"excerpt":{"rendered":"<p>Java \u30e1\u30e2\u30ea\u30fc\u4f7f\u7528\u91cf\u3092\u53d6\u5f97 Runtime.getRuntime().totalMemory\u3001freeMe [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":"","footnotes":""},"categories":[19],"tags":[],"class_list":["post-993","post","type-post","status-publish","format-standard","hentry","category-java"],"_links":{"self":[{"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/posts\/993","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/comments?post=993"}],"version-history":[{"count":9,"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/posts\/993\/revisions"}],"predecessor-version":[{"id":3636,"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/posts\/993\/revisions\/3636"}],"wp:attachment":[{"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/media?parent=993"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/categories?post=993"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chat-messenger.com\/zh_tw\/wp-json\/wp\/v2\/tags?post=993"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}