jmap(1) JDK Commands jmap(1)
NAME
jmap - print details of a specified process
SYNOPSIS
Note: This command is experimental and unsupported.
jmap [options] pid
options
This represents the jmap command-line options. See Options for
the jmap Command.
pid The process ID for which the information specified by the options
is to be printed. The process must be a Java process. To get a
list of Java processes running on a machine, use either the ps
command or, if the JVM processes are not running in a separate
docker instance, the jps command.
DESCRIPTION
The jmap command prints details of a specified running process.
Note:
This command is unsupported and might not be available in future releases
of the JDK. On Windows Systems where the dbgeng.dll file isn't present,
the Debugging Tools for Windows must be installed to make these tools
work. The PATH environment variable should contain the location of the
jvm.dll file that's used by the target process or the location from which
the core dump file was produced.
OPTIONS FOR THE JMAP COMMAND
-clstats pid
Connects to a running process and prints class loader statistics
of Java heap.
-finalizerinfo pid
Connects to a running process and prints information on objects
awaiting finalization.
-histo[:live] pid
Connects to a running process and prints a histogram of the Java
object heap. If the live suboption is specified, it then counts
only live objects.
-dump:dump_options pid
Connects to a running process and dumps the Java heap. The
dump_options include:
o live --- When specified, dumps only the live objects; if not
specified, then dumps all objects in the heap.
o format=b --- Dumps the Java heap in hprof binary format
o file=filename --- Dumps the heap to filename
Example: jmap -dump:live,format=b,file=heap.bin pid
JDK 27.0.1 2026 jmap(1)
openjdk27-zulu 27.30.107 - Generated Tue Oct 27 08:21:55 CDT 2026