Java: Get JVM Memory details

public class TestJVM {

    public static void main(String args[]) {

    Runtime r = Runtime.getRuntime();

    // amount of unallocated memory
    long free = r.freeMemory();

    // total amount of memory available allocated and unallocated.
    long total = r.totalMemory();

    // total amount of allocated memory
    long inuse = r.totalMemory() - r.freeMemory();

    // max memory JVM will attempt to use
    long max = r.maxMemory();
    System.out.println("******************************************");
    System.out.println("Java Virtual Machin SUMMARY ");
    System.out.println("Total Memory        : " + total/1024.00);
    System.out.println("Free                : " + free /1024.00);
    System.out.println("inuse               : " + inuse/1024.00 );
    System.out.println("Available Processors: " + r.availableProcessors());
    System.out.println("******************************************");
    // suggest now would be a good time for garbage collection
    System.gc();
    }
}