How to get Ram size and size of Hard disk using Java?

Question

How to get the Ram size and Hard disk size of the PC using Java? And Is it possible to get the currently logged user name on PC through java?

Answer 1

Disk size:

long diskSize = new File("/").getTotalSpace();

User name:

String userName = System.getProperty("user.name");

I'm not aware of a reliable way to determine total system memory in Java. On a Unix system you could parse /proc/meminfo. You can of course find the maximum memory available to the JVM:

long maxMemory = Runtime.getRuntime().maxMemory();

Edit: for completeness (thanks Suresh S), here's a way to get total memory with the Oracle JVM only:

long memorySize = ((com.sun.management.OperatingSystemMXBean) ManagementFactory
        .getOperatingSystemMXBean()).getTotalPhysicalMemorySize();

Answer 2

For Ram Size , if you are using java 1.5

java.lang.management package

com.sun.management.OperatingSystemMXBean mxbean = (com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();
System.out.println(mxbean.getTotalPhysicalMemorySize() + " Bytes "); 

Answer 3

import java.lang.management.*;
import java.io.*;

class max
{
    public static void main(String... a)
    {
        long diskSize = new File("/").getTotalSpace();
        String userName = System.getProperty("user.name");
        long maxMemory = Runtime.getRuntime().maxMemory();
        long memorySize = ((com.sun.management.OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean()).getTotalPhysicalMemorySize();
        System.out.println("Size of C:="+diskSize+" Bytes");
        System.out.println("User Name="+userName);

        System.out.println("RAM Size="+memorySize+" Bytes");
   }
}