MemoryTest.java

package bsh;

import org.junit.Test;

public class MemoryTest {

	static public double printUsage() {
		double cap = Runtime.getRuntime().totalMemory() - Runtime.getRuntime().freeMemory();
		cap /= 1048576;
		System.out.printf("Usage %f MB\n", cap);
		return cap;
	}
	
	static public void blockAlloc(int v) {
		byte t[] = new byte[v];
		System.out.printf("Alloc %d\n", t.length);
	}

	@Test
	public void memory_gc() {
		printUsage();
		int v = 1024 * 1048576;
		{
//			Case 1:
//			byte t[] = new byte[v];
//			System.out.printf("Alloc %d\n", t.length);
//			Case 2:
			blockAlloc(v);
		}
		printUsage();
		System.gc();
		printUsage();
	}
}