jcmd : where can I find complementary information

Question

jcmd is a promising tool regrouping utilities of jmap, jsp, etc...
You can find introduction and man page but still it\'s very light.

On the web, I

Answer 1

jcmd itself provides such information when applied on a specific Java process, and optionally a specific sub command.

How to get help:

• First get java process lists via jps or jcmd -l, if you don't know the pid of target java process yet, (e.g I will take java process with pid 8976 as example in subsequent steps).
• Then apply help sub command on a specific java process, e.g jcmd 8976 help, it will list available sub commands for the process.
• Then, get help for a specific command on the process, e.g jcmd 8976 help Thread.print, it will print help of Thread.print sub command.
• Then, execute the specific sub command on the process, e.g jcmd 8976 Thread.print or jcmd 8976 Thread.print | less -N

By the way, just as you mentioned, following link describes jcmd command briefly: https://docs.oracle.com/javase/8/docs/technotes/guides/troubleshoot/tooldescr006.html