如下所示：
****************************** /jmap jdk small version diffrent from jvm jdk vesionbegin/// [dev@iZ2ze8us9p89pfk02m9vs1Z ~]$ jmap -heap 1541 Attaching to process ID 1541, please wait... Error attaching to process: sun.jvm.hotspot.debugger.DebuggerException: cannot open binary file sun.jvm.hotspot.debugger.DebuggerException: sun.jvm.hotspot.debugger.DebuggerException: cannot open binary file at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal$LinuxDebuggerLocalWorkerThread.execute(LinuxDebuggerLocal.java:163) at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.attach(LinuxDebuggerLocal.java:278) at sun.jvm.hotspot.HotSpotAgent.attachDebugger(HotSpotAgent.java:671) at sun.jvm.hotspot.HotSpotAgent.setupDebuggerLinux(HotSpotAgent.java:611) at sun.jvm.hotspot.HotSpotAgent.setupDebugger(HotSpotAgent.java:337) at sun.jvm.hotspot.HotSpotAgent.go(HotSpotAgent.java:304) 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) 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: sun.jvm.hotspot.debugger.DebuggerException: cannot open binary file at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.attach0(Native Method) at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal.access$100(LinuxDebuggerLocal.java:62) at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal$1AttachTask.doit(LinuxDebuggerLocal.java:269) at sun.jvm.hotspot.debugger.linux.LinuxDebuggerLocal$LinuxDebuggerLocalWorkerThread.run(LinuxDebuggerLocal.java:138) /jmap jdk small version diffrent from jvm jdk vesionend/// /jmap jdk big version diffrent from jvm jdk vesionbegin/// Attaching to process ID 30413, 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.(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 /jmap jdk big version diffrent from jvm jdk vesionend/// ****************************************
【问题】
执行jmap -heap命令是报错，方法返回参数类型不匹配
【分析】
考虑执行jmap的jdk版本同目标jvm的jdk版本不一致：
1> 如果jmap的jdk版本比目标jvm高，执行会提示方法不兼容错误
2> 如果jmap的jdk版本比目标jvm低，执行会提示jdk版本不一致错误
【解决】
采用执行jmap的jdk版本同目标jvm的jdk版本保持一致。
补充知识：jmap -heap返回结果分析
using parallel threads in the new generation. using thread-local object allocation. Concurrent Mark-Sweep GC Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 4294967296 (4096.0MB) NewSize = 858980352 (819.1875MB) MaxNewSize = 858980352 (819.1875MB) OldSize = 3435986944 (3276.8125MB) NewRatio = 4 SurvivorRatio = 8 metaspaceSize = 21807104 (20.796875MB) CompressedClassSpaceSize = 1073741824 (1024.0MB) MaxmetaspaceSize = 17592186044415 MB G1HeapRegionSize = 0 (0.0MB) Heap Usage:
新生代
New Generation (Eden + 1 Survivor Space): capacity = 773128192 (737.3125MB) used = 95478696 (91.05558013916016MB) free = 677649496 (646.2569198608398MB) 12.349659084738175% used Eden Space: capacity = 687276032 (655.4375MB) used = 95478696 (91.05558013916016MB) free = 591797336 (564.3819198608398MB) 13.892336056322709% used From Space: capacity = 85852160 (81.875MB) used = 0 (0.0MB) free = 85852160 (81.875MB) 0.0% used To Space: capacity = 85852160 (81.875MB) used = 0 (0.0MB) free = 85852160 (81.875MB) 0.0% used concurrent mark-sweep generation: capacity = 3435986944 (3276.8125MB) used = 119572370833685648 (1.1403309901588979E11MB) free = 17478152948676 MB 3.480000732903997E9% used
根据以上数据，我们来check一些ratio：
NewRatio = 2 Eden Space capacity = 1063256064 (1014.0MB) From Space capacity = 4718592 (4.5MB) To Space capacity = 5242880 (5.0MB)
简单加法，
New size=1014.0+4.5+5.0=1023.5MB
MaxHeapSize = 3221225472 (3072.0MB)
年轻代占比：
1023.5/3072.0=1/3。
换算NewRatio的计算，老年代/新生代，结果为2
以上这篇解决JMap抓取heap使用统计信息报错的问题就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持考高分网。
