MemoryDemo.java Source code

Introduction

Here is the source code for MemoryDemo.java

Source

class MemoryDemo {
    public static void main(String args[]) {
        Runtime r = Runtime.getRuntime();
        long mem1, mem2;
        Integer someints[] = new Integer[1000];

        System.out.println("Total memory is: " + r.totalMemory());

        mem1 = r.freeMemory();
        System.out.println("Initial free memory: " + mem1);
        r.gc();
        mem1 = r.freeMemory();
        System.out.println("Free memory after garbage collection: " + mem1);

        for (int i = 0; i < 1000; i++)
            someints[i] = new Integer(i); // allocate integers

        mem2 = r.freeMemory();
        System.out.println("Free memory after allocation: " + mem2);
        System.out.println("Memory used by allocation: " + (mem1 - mem2));

        for (int i = 0; i < 1000; i++)
            someints[i] = null;

        r.gc(); // request garbage collection

        mem2 = r.freeMemory();
        System.out.println("Free memory after collecting" + " discarded Integers: " + mem2);

    }
}