Java Memory Used getMemoryUsed()

Description

Get the used memory in KB.

License

Mozilla Public License

Return

the used memory

Declaration

public static int getMemoryUsed() 

Method Source Code

//package com.java2s;
/*/*from  w  ww. j  av a  2 s.  co  m*/
 * Copyright 2004-2014 H2 Group. Multiple-Licensed under the MPL 2.0,
 * and the EPL 1.0 (http://h2database.com/html/license.html).
 * Initial Developer: H2 Group
 */

public class Main {
    private static final int GC_DELAY = 50;
    private static final int MAX_GC = 8;
    private static long lastGC;

    /**
     * Get the used memory in KB.
     * This method possibly calls System.gc().
     *
     * @return the used memory
     */
    public static int getMemoryUsed() {
        collectGarbage();
        Runtime rt = Runtime.getRuntime();
        long mem = rt.totalMemory() - rt.freeMemory();
        return (int) (mem >> 10);
    }

    private static synchronized void collectGarbage() {
        Runtime runtime = Runtime.getRuntime();
        long total = runtime.totalMemory();
        long time = System.currentTimeMillis();
        if (lastGC + GC_DELAY < time) {
            for (int i = 0; i < MAX_GC; i++) {
                runtime.gc();
                long now = runtime.totalMemory();
                if (now == total) {
                    lastGC = System.currentTimeMillis();
                    break;
                }
                total = now;
            }
        }
    }
}

Related

1. calcUsedMemorySize()
2. disposeUnusedMemory()
3. getAvailableUnusedMemory()
4. getMemoryInUse()
5. getMemoryUse()
6. getMemoryUsed()
7. getMemoryUsed()
8. getMemoryUsedBytes ()
9. getMemoryUsege()