深入理解Java虚拟机 示例代码

 

package com.sam;

import java.util.ArrayList;
import java.util.List;

/**
 * -verbose:gc -Xms20M -Xmx20M -Xmn10M -XX:+PrintGCDetails -XX:SurvivorRatio=8
 * @author Sam
 *
 */
public class HeapOOM {
    static class OOMObject {
       
    }
   
    public static void main(String[] args) {
        List<OOMObject> list = new ArrayList<OOMObject>();
        while(true) {
            list.add(new OOMObject());
        }
    }
}

 

 

 

 

package com.sam;

public class MinorGC {
private static final int _1MB = 1024*1024;

/**
 * VM arg: -verbose:gc -Xms20M -Xmx20M -Xmn10M -XX:SurvivorRatio=8 -XX:+PrintGCDetails
 */
	public static void testAllocation() {
		byte[] allocation1, allocation2, allocation3, allocation4;
		allocation1 = new byte[2*_1MB];
		allocation2 = new byte[2*_1MB];
		allocation3 = new byte[2*_1MB];
		allocation4 = new byte[4*_1MB]; // occur Minor GC
	}

	public static void main(String[] args) {
		MinorGC minorGC = new MinorGC();
		minorGC.testAllocation();

	}

}