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jcmd - Diagnostic Command

jcmd is a utility to send diagnostic command requests to a running Java Virtual Machine.

SYNOPSIS

    jcmd [ option ] 
    jcmd <pid | main class> PerfCounter.print
    jcmd <pid | main class> command [arguments]
    jcmd <pid | main class> -f file

DESCRIPTION

jcmd is a utility to send diagnostic command requests to a Java Virtual Machine supporting this feature.

Used without arguments or with the -l option, jcmd prints the list of running Java processes with their process id, their main class and their command line arguments.

When a process id is specified on the command line, jcmd sends the diagnostic command request to the process with this id.

When a main class is specified on the command line, jcmd sends the diagnostic command request to all Java processes with this main class.

With the PerfCounter.print argument, jcmd prints the performance counters available on the targeted Java process(es).

With the -f option, jcmd sends to the targeted Java process(es) the diagnostic commands stored in the file file.

OPTIONS

Options are mutually exclusive. Options, if used, should follow immediately after the command name.

-l
Prints the list of running Java processes with their process id, their main class and their command line arguments.
-h
Prints a help message.
-help
Prints a help message.

PARAMETERS

pid
Identifies the process that receives the diagnostic command requests. The process must be a Java process. To get a list of Java processes running on a machine, use jps(1) or jcmd(1).
main class
Main class of the process that receives the diagnostic command requests. If several running Java processes share this main class, the diagnostic command request is sent to all these processes. To get a list of Java processes running on a machine, use jps(1) or jcmd(1).
command [arguments]
Invoke the diagnostic command called command on the targeted Java process(es). The list of available diagnostic commands for a given process can be obtained by invoking the help command on this process. Each diagnostic command has its own set of arguments, which can be obtained by invoking the help command followed by the command name.
Counter.print
Print the performance counters available on the targeted Java process(es). The list of performance counters may vary with the Java process.
-f file
Read commands from file and invoke them on the targeted Java process(es). In file, each command must be written on a single line. Lines starting with # are ignored. Processing of file ends when all lines have been invoked or when a line containing the stop keyword is read.

SEE ALSO

jps(1)

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