package cn.com.pcalpha;

public class GcTest {

/**

*

* -Xms5m

* -Xmx20m

* -XX:+PrintGC

* -XX:+PrintGCDetails

* -XX:SurvivorRatio 设置eden跟from/to的比例 -XX:survivorRatio =eden/from=eden/to

* -XX:NewRatio 新生代老年代的比率 -XX:newRatio = 老年代/新生代

* -XX:UseSerialGC

* @param args

*/

public static void main(String[] args) {

System.out.println("max memery :"+Runtime.getRuntime().maxMemory());

System.out.println("free memery :"+Runtime.getRuntime().freeMemory());

System.out.println("total memery :"+Runtime.getRuntime().totalMemory());

byte[] i = new byte[1*1024*1024];

System.out.println("分配了1M");

System.out.println("max memery :"+Runtime.getRuntime().maxMemory());

System.out.println("free memery :"+Runtime.getRuntime().freeMemory());

System.out.println("total memery :"+Runtime.getRuntime().totalMemory());

byte[] j = new byte[4*1024*1024];

System.out.println("分配了4M");

System.out.println("max memery :"+Runtime.getRuntime().maxMemory());

System.out.println("free memery :"+Runtime.getRuntime().freeMemory());

System.out.println("total memery :"+Runtime.getRuntime().totalMemory());

}

}