查看堆内存(histogram)中的对象数量及大小

执行命令： jmap -histo 3331

num #instances #bytes class name

编号 个数 字节 类名

----------------------------------------------

1: 7 1322080 [I

2: 5603 722368 <methodKlass>

3: 5603 641944 <constMethodKlass>

4: 34022 544352 java.lang.Integer

5: 371 437208 <constantPoolKlass>

6: 336 270624 <constantPoolCacheKlass>

7: 371 253816 <instanceKlassKlass>