查看jvm内存大小

 public static String toMemoryInfo() { 

	       Runtime currRuntime = Runtime.getRuntime (); 
	       int nFreeMemory = ( int ) (currRuntime.freeMemory() / 1024 / 1024); 
	       int nTotalMemory = ( int ) (currRuntime.totalMemory() / 1024 /1024); 
	       return nFreeMemory + "M/" + nTotalMemory + "M(free/total)" ;	     
	  }