关于Caused by: java.lang.InternalError: void* type hasn't been seen when parsing int*
解决方法：
在linux使用 jmap -heap 2917查看jvm内存时报以下错误，原因是执行jmap命令的jdk版本和所监控的jvm的jdk版本不一致，一般是你系统安装了多个版本的jdk导致的。
[root@xxx ~]# jmap -heap 2917
Attaching to process ID 2917, please wait...
Exception in thread "main" java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at sun.tools.jmap.JMap.runTool(JMap.java:201)
at sun.tools.jmap.JMap.main(JMap.java:130)
Caused by: java.lang.InternalError: void* type hasn't been seen when parsing int*
at sun.jvm.hotspot.HotSpotTypeDataBase.recursiveCreateBasicPointerType(HotSpotTypeDataBase.java:721)
at sun.jvm.hotspot.HotSpotTypeDataBase.lookupType(HotSpotTypeDataBase.java:134)
at sun.jvm.hotspot.HotSpotTypeDataBase.lookupOrCreateClass(HotSpotTypeDataBase.java:631)
at sun.jvm.hotspot.HotSpotTypeDataBase.createType(HotSpotTypeDataBase.java:751)
at sun.jvm.hotspot.HotSpotTypeDataBase.readVMTypes(HotSpotTypeDataBase.java:195)
at sun.jvm.hotspot.HotSpotTypeDataBase.<init>(HotSpotTypeDataBase.java:89)
at sun.jvm.hotspot.HotSpotAgent.setupVM(HotSpotAgent.java:395)
at sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:305)
at sun.jvm.hotspot.HotSpotAgent.attach(HotSpotAgent.java:140)
at sun.jvm.hotspot.tools.Tool.start(Tool.java:185)
at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
at sun.jvm.hotspot.tools.HeapSummary.main(HeapSummary.java:49)
... 6 more