import java.lang.management.MemoryMXBean;
import java.lang.management.ManagementFactory;
import java.lang.management.MemoryUsage;
 
import java.util.Random;
 
public class TestGC
{
	public static void main(String[] args)
	{
		Random rand = new Random();
		MemoryMXBean memory = ManagementFactory.getMemoryMXBean();
		MemoryUsage usage = memory.getHeapMemoryUsage();
		System.out.println("init="+usage.getInit());
		System.out.println("used="+usage.getUsed());
		System.out.println("committed="+usage.getCommitted());
		System.out.println("max="+usage.getMax());
		for (int i=0; i<10; i++)
		{
			int iteration=0;
			long t0 = System.currentTimeMillis();
			while (true)
			{
				String s = String.valueOf(rand.nextInt());
				if (++iteration == 100)
				{
					iteration = 0;
					if (System.currentTimeMillis()-t0 > 15000)
						break;
				}
			}
			usage = memory.getHeapMemoryUsage();
			System.out.println();
			System.out.println("used="+usage.getUsed());
			System.out.println("committed="+usage.getCommitted());
		}
	}
}