Java Memory Usage getMemoryInfo()

Description

get Memory Info

License

Apache License

Declaration

public static String getMemoryInfo() 

Method Source Code

//package com.java2s;
//License from project: Apache License 

import java.lang.management.ManagementFactory;
import java.lang.management.MemoryPoolMXBean;
import java.lang.management.MemoryUsage;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.*;

public class Main {
    private static final NumberFormat MEM_FMT = new DecimalFormat("##,###.##");

    public static String getMemoryInfo() {
        Runtime run = Runtime.getRuntime();
        StringBuilder memoryInfo = new StringBuilder();
        memoryInfo.append("Runtime free: ").append(kbString(run.freeMemory())).append("\nRuntime max:")
                .append(kbString(run.maxMemory())).append("\nRuntime total:").append(kbString(run.totalMemory()));
        Iterator<MemoryPoolMXBean> iter = ManagementFactory.getMemoryPoolMXBeans().iterator();
        while (iter.hasNext()) {
            MemoryPoolMXBean item = iter.next();
            MemoryUsage usage = item.getUsage();
            memoryInfo.append("\nMX ").append(item.getName()).append("(").append(item.getType()).append("): ")
                    .append("used: ").append(kbString(usage.getUsed())).append(", init: ")
                    .append(kbString(usage.getInit())).append(", committed: ")
                    .append(kbString(usage.getCommitted())).append(", max: ").append(kbString(usage.getMax()));
        }/*from   w  ww.ja  va2  s. c  om*/
        return memoryInfo.toString();
    }

    public static String kbString(long memBytes) {
        return MEM_FMT.format(memBytes / 1024) + " kb";
    }

    private static String format(long bytes) {
        double val = bytes;
        int mag = 0;
        while (val > 1024) {
            val = val / 1024;
            mag++;
        }

        String formatted = MEM_FMT.format(val);
        switch (mag) {
        case 0:
            return formatted + " bytes";
        case 1:
            return formatted + " kb";
        case 2:
            return formatted + " Mb";
        case 3:
            return formatted + " Gb";
        default:
            return "WTF?";
        }
    }
}

Related

1. describeMemoryUsage()
2. estimateMemoryUsage(String s)
3. getMemberName(int number)
4. getMemInfo()
5. getMemoryFootprint()
6. getMemoryInfo()
7. getMemoryInfo()
8. getMemorySize(long size)
9. getMemoryStatus()