Java Memory Usage getMemoryUsage()

Description

Returns the amount of memory currently used by the JVM.

License

Open Source License

Return

The amount of memory used in bytes. Calculated by totalMemory-freeMemory

Declaration

private static long getMemoryUsage() 

Method Source Code

//package com.java2s;
/*//from   w w w  .  j a v a  2s  .  co m
 * Copyright 2016  Generic Problem Solver Project
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

public class Main {
    /**
     * The runtime object currently used to communicate with the environment
     */
    private static final Runtime runtime = Runtime.getRuntime();

    /**
     * Returns the amount of memory currently used by the JVM.
     * 
     * @return The amount of memory used in bytes. Calculated by totalMemory-freeMemory
     */
    private static long getMemoryUsage() {
        hardClean();
        return runtime.totalMemory() - runtime.freeMemory();
    }

    /**
     * Will clear as much memory as possible, resulting in a more accurate comparision
     */
    private static void hardClean() {
        // Running it once is actually not enough
        // Running it multiple times results in a way more accurate memory reading
        for (int i = 0; i < 5; ++i) {
            runtime.runFinalization();
            Thread.yield();
            runtime.gc();
        }
    }
}

Related

1. getMemoryUsage()
2. getMemoryUsage()
3. getMemoryUsage()
4. getMemoryUsage()
5. getMemoryUsage()
6. getMemoryUsage()
7. getMemoryUsage()
8. getMemoryUsage()
9. getMemoryUsage()