{"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":"runtime-totalmemory-freememory","status":"publish","type":"post","link":"https:\/\/chat-messenger.com\/vi\/blog\/java\/tong-thoi-gian-chay-bo-nho-mien-phi","title":{"rendered":"Nh\u1eadn m\u1ee9c s\u1eed d\u1ee5ng b\u1ed9 nh\u1edb Java"},"content":{"rendered":"<h2 class=\"common_title\"><a name=\"0\">Java <strong>k\u00fd \u1ee9c<\/strong>Nh\u1eadn m\u1ee9c s\u1eed d\u1ee5ng <strong>Runtime.getRuntime().totalMemory, freeMemory<\/strong><\/a><\/h2>\n<p>\n<strong>Java <\/strong> Tr\u1ea3 v\u1ec1 th\u00f4ng tin &quot;T\u1ed5ng c\u1ed9ng&quot;, &quot;\u0110\u00e3 s\u1eed d\u1ee5ng&quot; v\u00e0 &quot;C\u00f3 th\u1ec3 s\u1eed d\u1ee5ng t\u1ed1i \u0111a&quot; cho th\u00f4ng tin b\u1ed9 nh\u1edb m\u00e1y \u1ea3o.<br \/>\nGi\u1ea3i th\u00edch t\u1eebng m\u1ee5c nh\u01b0 sau.\n<\/p>\n<ul>\n<li><strong>t\u1ed5ng c\u1ed9ng<\/strong>...<strong>Runtime.getRuntime().totalMemory()<\/strong>\u0110\u00e2y l\u00e0 dung l\u01b0\u1ee3ng b\u1ed9 nh\u1edb \u0111\u01b0\u1ee3c ph\u00e2n b\u1ed5 cho m\u00e1y \u1ea3o Java.<\/li>\n<li><strong>s\u1ed1 ti\u1ec1n c\u1ea7n s\u1eed d\u1ee5ng<\/strong>...<strong>Runtime.getRuntime().totalMemory()<\/strong>-<strong>Runtime.getRuntime().freeMemory()<\/strong>tr\u1edf n\u00ean,<br \/>\nM\u1ee9c s\u1eed d\u1ee5ng b\u1ed9 nh\u1edb c\u1ee7a c\u00e1c \u0111\u1ed1i t\u01b0\u1ee3ng hi\u1ec7n \u0111\u01b0\u1ee3c ph\u00e2n b\u1ed5 trong b\u1ed9 nh\u1edb.<\/li>\n<li><strong>t\u1ed1i \u0111a c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng<\/strong>...<strong>Runtime.getRuntime().maxMemory()<\/strong>l\u00e0 dung l\u01b0\u1ee3ng b\u1ed9 nh\u1edb t\u1ed1i \u0111a m\u00e0 M\u00e1y \u1ea3o Java s\u1ebd c\u1ed1 g\u1eafng s\u1eed d\u1ee5ng.<br \/>\nN\u1ebfu dung l\u01b0\u1ee3ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng g\u1ea7n b\u1eb1ng t\u1ed5ng s\u1ed1 v\u00e0 b\u1ed9 nh\u1edb tr\u1ed1ng kh\u00f4ng th\u1ec3 \u0111\u01b0\u1ee3c b\u1ea3o \u0111\u1ea3m ngay c\u1ea3 khi thu gom r\u00e1c, m\u00e1y \u1ea3o Java s\u1ebd m\u1edf r\u1ed9ng \u0111\u1ebfn dung l\u01b0\u1ee3ng &quot;t\u1ed1i \u0111a kh\u1ea3 d\u1ee5ng&quot;.<\/li>\n<\/ul>\n<h2 class=\"common_title\"><a name=\"1\">ch\u01b0\u01a1ng tr\u00ecnh m\u1eabu<\/a><\/h2>\n<pre class=\"sample_src\">\/** * Tr\u1ea3 v\u1ec1 th\u00f4ng tin v\u1ec1 t\u1ed5ng b\u1ed9 nh\u1edb c\u1ee7a m\u00e1y \u1ea3o Java, dung l\u01b0\u1ee3ng \u0111\u00e3 s\u1eed d\u1ee5ng v\u00e0 * dung l\u01b0\u1ee3ng b\u1ed9 nh\u1edb t\u1ed1i \u0111a m\u00e0 n\u00f3 c\u1ed1 g\u1eafng s\u1eed d\u1ee5ng. * @return Th\u00f4ng tin b\u1ed9 nh\u1edb m\u00e1y \u1ea3o Java *\/ public static String getMemoryInfo() { DecimalFormat f1 = new DecimalFormat(&quot;#,###KB&quot;); DecimalFormat f2 = new DecimalFormat(&quot;##.#&quot;); long free = Runtime.getRuntime ( ).freeMemory() \/ 1024; t\u1ed5ng d\u00e0i = Runtime.getRuntime().totalMemory() \/ 1024; d\u00e0i t\u1ed1i \u0111a = Runtime.getRuntime().maxMemory() \/ 1024; s\u1eed d\u1ee5ng l\u00e2u = t\u1ed5ng - mi\u1ec5n ph\u00ed; t\u1ef7 l\u1ec7 g\u1ea5p \u0111\u00f4i = ( \u0111\u00e3 s\u1eed d\u1ee5ng * 100 \/ (double)total); Th\u00f4ng tin chu\u1ed7i = &quot;Th\u00f4ng tin b\u1ed9 nh\u1edb Java: T\u1ed5ng = + f1.format(total) + &quot;, &quot; + &quot;Used = + f1.format(used) + &quot; (&quot; + f2.format( t\u1ef7 l\u1ec7) + &quot;%)&quot; + &quot;c\u00f3 s\u1eb5n t\u1ed1i \u0111a=&quot;+f1.format(max); th\u00f4ng tin tr\u1ea3 v\u1ec1; }\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\">K\u1ebft qu\u1ea3 th\u1ef1c hi\u1ec7n 1<\/a><\/h2>\n<p>\u25c6V\u00ed d\u1ee5 th\u1ef1c thi<\/p>\n<pre class=\"sample_src\">public static void main(String[] args) { System.out.println(getMemoryInfo()); }\r\n<\/pre>\n<p>\u25c6K\u1ebft qu\u1ea3 \u0111\u1ea7u ra<\/p>\n<pre class=\"console\">Th\u00f4ng tin b\u1ed9 nh\u1edb Java: t\u1ed5ng=1.984KB, m\u1ee9c s\u1eed d\u1ee5ng=458KB (23.1%), m\u1ee9c s\u1eed d\u1ee5ng t\u1ed1i \u0111a=65.088KB\r\n<\/pre>\n<h2 class=\"common_title\"><a name=\"3\">K\u1ebft qu\u1ea3 th\u1ef1c hi\u1ec7n 2<\/a><\/h2>\n<p>\u25c6V\u00ed d\u1ee5 th\u1ef1c thi<br \/>\nH\u00e3y th\u1eed thay \u0111\u1ed5i k\u00edch th\u01b0\u1edbc v\u00f9ng heap Java v\u00e0 ch\u1ea1y.<br \/>\nGi\u00e1 tr\u1ecb c\u1ee7a k\u00edch th\u01b0\u1edbc v\u00f9ng heap Java c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c ch\u1ec9 \u0111\u1ecbnh d\u01b0\u1edbi d\u1ea1ng t\u00f9y ch\u1ecdn c\u1ee7a l\u1ec7nh Java.<\/p>\n<div class=\"point\">\njava -Xms64m -Xmx512m Ch\u00ednh <\/p>\n<p>-Xms k\u00edch th\u01b0\u1edbc heap ban \u0111\u1ea7u<br \/>\nCh\u1ec9 \u0111\u1ecbnh ph\u00e2n b\u1ed5 b\u1ed9 nh\u1edb ban \u0111\u1ea7u cho m\u00e1y \u1ea3o Java. M\u1eb7c \u0111\u1ecbnh l\u00e0 2MB.<br \/>\n-Xmx k\u00edch th\u01b0\u1edbc heap t\u1ed1i \u0111a<br \/>\nCh\u1ec9 \u0111\u1ecbnh ph\u00e2n b\u1ed5 b\u1ed9 nh\u1edb t\u1ed1i \u0111a cho m\u00e1y \u1ea3o Java. M\u1eb7c \u0111\u1ecbnh l\u00e0 64 MB.\n<\/div>\n\n<pre class=\"sample_src\">public static void main(String[] args) { System.out.println(getMemoryInfo()); }\r\n<\/pre>\n<p>\u25c6K\u1ebft qu\u1ea3 \u0111\u1ea7u ra<\/p>\n<pre class=\"console\">Th\u00f4ng tin b\u1ed9 nh\u1edb Java: t\u1ed5ng=65.088KB, m\u1ee9c s\u1eed d\u1ee5ng=524KB (0.8%), m\u1ee9c s\u1eed d\u1ee5ng t\u1ed1i \u0111a=520.256KB\r\n<\/pre>\n<p>&quot;Total Runtime.getRuntime().totalMemory()&quot; l\u00e0<strong>-Xms<\/strong>, &quot;Runtime.getRuntime().maxMemory()&quot; c\u00f3 s\u1eb5n t\u1ed1i \u0111a<strong>-Xmx<\/strong>N\u00f3 \u0111\u01b0\u1ee3c li\u00ean k\u1ebft v\u1edbi.<\/p>","protected":false},"excerpt":{"rendered":"<p>Nh\u1eadn m\u1ee9c s\u1eed d\u1ee5ng b\u1ed9 nh\u1edb Java Runtime.getRuntime().totalMemory, freeMe [\u2026]<\/p>","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"swell_btn_cv_data":""},"categories":[19],"tags":[],"_links":{"self":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts\/993"}],"collection":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/comments?post=993"}],"version-history":[{"count":9,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts\/993\/revisions"}],"predecessor-version":[{"id":3636,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/posts\/993\/revisions\/3636"}],"wp:attachment":[{"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/media?parent=993"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/categories?post=993"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/chat-messenger.com\/vi\/wp-json\/wp\/v2\/tags?post=993"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}