Heap Usage:
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.RuntimeException: unknown CollectedHeap type : class sun.jvm.hotspot.gc_interface.CollectedHeap
at sun.jvm.hotspot.tools.HeapSummary.run(HeapSummary.java:144)
at sun.jvm.hotspot.tools.Tool.startInternal(Tool.java:260)
at sun.jvm.hotspot.tools.Tool.start(Tool.java:223)
at sun.jvm.hotspot.tools.Tool.execute(Tool.java:118)
at sun.jvm.hotspot.tools.HeapSummary.main(HeapSummary.java:49)
- 查找源：sudo apt-cahce search openjdk
- 安装查到的源
openjdk-8-dbg : sudo apt install openjdk-8-dbg
- 再次运行 jmap -heap pid 可顺利展示堆内存信息
Heap Configuration:
MinHeapFreeRatio = 0
MaxHeapFreeRatio = 100
MaxHeapSize = 2042626048 (1948.0MB)
NewSize = 42467328 (40.5MB)
MaxNewSize = 680525824 (649.0MB)
OldSize = 85458944 (81.5MB)
NewRatio = 2
SurvivorRatio = 8
MetaspaceSize = 21807104 (20.796875MB)
CompressedClassSpaceSize = 1073741824 (1024.0MB)
MaxMetaspaceSize = 17592186044415 MB
G1HeapRegionSize = 0 (0.0MB)
Heap Usage:
PS Young Generation
Eden Space:
capacity = 217579520 (207.5MB)
used = 164886464 (157.24798583984375MB)
free = 52693056 (50.25201416015625MB)
75.7821618505271% used
From Space:
capacity = 16252928 (15.5MB)
used = 15868136 (15.133033752441406MB)
free = 384792 (0.36696624755859375MB)
97.63247582220262% used
To Space:
capacity = 20447232 (19.5MB)
used = 0 (0.0MB)
free = 20447232 (19.5MB)
0.0% used
PS Old Generation
capacity = 130547712 (124.5MB)
used = 29376592 (28.015701293945312MB)
free = 101171120 (96.48429870605469MB)
22.502571320438% used
28075 interned Strings occupying 2757984 bytes.