1.查询某个进程堆内存映像文件情况
举例(jmap [PID]):
jmap 83573
2.查询Java堆详细信息
举例(jmap -heap [PID]):
jmap -heap 83573
3.查询堆中存活对象统计信息
举例(jmap -histo:live [PID] | more)
jmap -histo:live 83573 | more
class name解释
[B byte[]
[C char[]
[I int[]
[S short[]
[[I int[][]
constMethodKlass/methodKlass/constantPoolKlass/constantPoolCacheKlass/instanceKlassKlass/methodDataKlass 与Classloader相关,常驻Perm区
4.查询等待终结的对象信息
举例(jmap -finalizerinfo [PID] | more):
jmap -finalizerinfo 83573 | more