1 /**
 2  * Created by wb-xxd249566 on 2017/4/1.
 3  * -Xmx20m -Xms5m -XX:+PrintCommandLineFlags -XX:+PrintGCDetails -XX:+UseSerialGC
 4  */
 5 public class HeapAlloc {
 6 
 7     public static void main(String[] args){
 8         printMemoryStatus();
 9         alloc(1);
10         printMemoryStatus();
11         alloc(4);
12         printMemoryStatus();
13     }
14 
15     public static void printMemoryStatus(){
16         System.out.println("Max Memory="+Runtime.getRuntime().maxMemory()+"bytes");
17         System.out.println("Free Memory="+Runtime.getRuntime().freeMemory()+"bytes");
18         System.out.println("Total Memory="+Runtime.getRuntime().totalMemory()+"bytes");
19     }
20 
21     public static void alloc(int size){
22         byte[] b = new byte[size*1024*1024];
23         System.out.println("Alloc "+size+"M Space");
24         System.out.println("=========================================================");
25     }
26 }