Here you can find the source of availableMemory()
public static long availableMemory()
//package com.java2s; /**//from w w w. jav a 2 s .com * Copyright 2000-2006 DFKI GmbH. * All Rights Reserved. Use is subject to license terms. * * This file is part of MARY TTS. * * MARY TTS is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, version 3 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * */ public class Main { /** * Determine the amount of available memory. "Available" memory is calculated as * <code>(max - total) + free</code>. * @return the number of bytes of memory available according to the above algorithm. */ public static long availableMemory() { Runtime rt = Runtime.getRuntime(); return rt.maxMemory() - rt.totalMemory() + rt.freeMemory(); } }