Here you can find the source of memoryUsage()
public static final String memoryUsage()
//package com.java2s; /******************************************************************** * * Copyright (c) 2006-2007 Berlin Brown and botnode.com All Rights Reserved * * http://www.opensource.org/licenses/bsd-license.php /* w w w . ja v a 2s . c o m*/ * All rights reserved. * Redistribution and use in source and binary forms, with or without modification, * are permitted provided that the following conditions are met: * * Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * * Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of the Botnode.com (Berlin Brown) nor * the names of its contributors may be used to endorse or promote * products derived from this software without specific prior written permission. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * Date: 1/5/2009 * 7/15/2009 - Added Clojure 1.0, other performance fixes and cleanups. * * Main Description: Light Log Viewer is a tool for making it easier to search log files. * Light Log Viewer adds some text highlighting, quick key navigation to text files, simple graphs * and charts for monitoring logs, file database to quickly navigate to files of interest, * and HTML to PDF convert tool. * Light Log was developed with a combination of Clojure 1.0, Java and Scala with use of libs, SWT 3.4, JFreeChart, iText. * * Quickstart : the best way to run the Light Log viewer is to click on the win32 batch script light_logs.bat * (you may need to edit the Linux script for Unix/Linux environments). * Edit the win32 script to add more heap memory or other parameters. * * The clojure source is contained in : HOME/src/octane * The java source is contained in : HOME/src/java/src * * To build the java source, see : HOME/src/java/build.xml and build_pdf_gui.xml * * Metrics: (as of 7/15/2009) Light Log Viewer consists of 6500 lines of Clojure code, and contains wrapper code * around the Java source. There are 2000+ lines of Java code in the Java library for Light Log Viewer. * * Additional Development Notes: The SWT gui and other libraries are launched from a dynamic classloader. Clojure is also * started from the same code, and reflection is used to dynamically initiate Clojure. See the 'start' package. The binary * code is contained in the octane_start.jar library. * * Home Page: http://code.google.com/p/lighttexteditor/ * * Contact: Berlin Brown <berlin dot brown at gmail.com> *********************************************************************/ public class Main { private static final Runtime runtime = Runtime.getRuntime(); public static final double megabytes = 1024.0 * 1024.0; public static final String memoryUsage() { final StringBuffer buf = new StringBuffer(80); buf.append("(used:").append(usedMemorym()); buf.append("M/").append(freeMemorym()); buf.append("M [").append(totalMemorym()); buf.append("M,").append(maxMemorym()); buf.append("M ])"); return buf.toString(); } public static final int usedMemorym() { return (int) Math.floor((usedMemoryb() / megabytes)); } public static final int freeMemorym() { return (int) Math.floor((freeMemoryb() / megabytes)); } public static final int totalMemorym() { return (int) Math.floor((totalMemoryb() / megabytes)); } public static final int maxMemorym() { return (int) Math.floor((maxMemoryb() / megabytes)); } public static final long usedMemoryb() { return totalMemoryb() - freeMemoryb(); } public static final long freeMemoryb() { return runtime.freeMemory(); } public static final long totalMemoryb() { return runtime.totalMemory(); } public static final long maxMemoryb() { return runtime.maxMemory(); } }