jcmd
Sends diagnostic command requests to a running Java Virtual Machine (JVM).
Synopsis
jcmd [-l|-h|-help]
jcmd pid|main-class PerfCounter.print
jcmd pid|main-class -f filename
jcmd pid|main-class command[ arguments]
Description
The jcmd utility is used to send diagnostic command requests to the JVM. It must be used on the same machine on which the JVM is running, and have the same effective user and group identifiers that were used to launch the JVM.
使用方式
jcmd 或者 jcmd -l 可以查看当前机器上，所有jvm的实例进程
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jcmd -h 可以查看帮助文档
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通过 jcmd <pid|main-class> help 的方式可以获得当前进程，哪些command是支持的
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再通过 jcmd <pid|main-class> help command 的方式，可以查看当前的command的使用方式
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最后 可以执行 jcmd <pid|main-class> <command arguments> send command to vm
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关于具体的 command的含义可以通过help指令查看
