Returns the amount of memory currently used by the Java Virtual Machine. - Java Java Virtual Machine

Java examples for Java Virtual Machine:Memory

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Description

Returns the amount of memory currently used by the Java Virtual Machine.

Demo Code

/*/*from  w w  w .  j a  v  a2s  .com*/
 * Copyright (c) 2010-2013, University of Sussex
 * All rights reserved.
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 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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//package com.java2s;

public class Main {
    /**
     * Returns the amount of memory currently used by the Java Virtual Machine.
     * The value returned by this method may vary over time. Calling the
     * {@link Runtime#gc()} method may result in a decreasing the value return
     * by usedMemory.
     *
     * @return an approximation to the amount of memory currently used by
     *         allocated objects, measured in bytes.
     */
    public static long usedMemory() {
        return allocatedMemory() - freeAllocatedMemory();
    }

    /**
     * Returns the total amount of memory in the Java virtual machine. The value
     * returned by this method may vary over time, depending on the host
     * environment.
     *
     * @return total amount of memory currently available for current and future
     *         objects, measured in bytes.
     */
    public static long allocatedMemory() {
        return Runtime.getRuntime().totalMemory();
    }

    /**
     * Returns the amount of free memory in the Java Virtual Machine. Calling
     * the {@link Runtime#gc()} method may result in increasing the value
     * returned by freeMemory.
     *
     * @return an approximation to the total amount of memory currently
     *         available for future allocated objects, measured in bytes.
     */
    public static long freeAllocatedMemory() {
        return Runtime.getRuntime().freeMemory();
    }
}

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