Java Memory Free getFreeMemory()

Description

Gets the JVM free memory.

License

Apache License

Return

JVM free memory in bytes

Declaration

public static long getFreeMemory() 

Method Source Code

//package com.java2s;
/* Copyright 2010-2014 Norconex Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License./*from  w w w . j  a  v  a  2  s .c o m*/
 */

public class Main {
    /**
     * Gets the JVM free memory.
     * The free memory is calculated by taking the JVM current free memory, plus
     * the difference between the maximum possible JVM memory and the
     * total JVM memory taken so far.
     * @return JVM free memory in bytes
     */
    public static long getFreeMemory() {
        return getFreeMemory(false);
    }

    /**
     * Gets the JVM free memory.
     * The free memory is calculated by taking the JVM current free memory, plus
     * the difference between the maximum possible JVM memory and the
     * total JVM memory taken so far.
     * @param attemptGC <code>true</code> to attempts to perform garbage 
     *     collection to free up as much unused memory as possible 
     *     before assessing how much memory remains in the JVM instance.
     * @return JVM free memory in bytes
     */
    public static long getFreeMemory(boolean attemptGC) {
        if (attemptGC) {
            System.gc();
        }
        Runtime runtime = Runtime.getRuntime();
        return runtime.freeMemory() + (runtime.maxMemory() - runtime.totalMemory());
    }
}

Related

1. freeReserveMemory()
2. getFreeJVMMemoryMB()
3. getFreeLiveMemory()
4. getFreeMemory()
5. getFreeMemory()
6. getFreeMemory(boolean preRunGarbageCollector)
7. getFreeMemoryForAppInKB()
8. getFreeMemoryInMb()
9. getFreeMemoryKb()