jmap [ options ] pid
jmap [ options ] executable core
jmap [ options ] [ pid ] server-id@ ] remote-hostname-or-IP
The command-line options. See Options.
pid The process ID for which the memory map is to be printed. The
process must be a Java process. To get a list of Java processes
running on a machine, use the jps(1) command.
The Java executable from which the core dump was produced.
core The core file for which the memory map is to be printed.
The remote debug server hostname or IP address. See
An optional unique ID to use when multiple debug servers are
running on the same remote host.
The jmap command prints shared object memory maps or heap memory
details of a specified process, core file, or remote debug server. If
the specified process is running on a 64-bit Java Virtual Machine
(JVM), then you might need to specify the -J-d64 option, for example:
jmap-J-d64 -heap pid.
Note: This utility is unsupported and might not be available in future
releases of the JDK. On Windows Systems where the dbgeng.dll file is
not present, 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 is used by the target process or the
location from which the crash dump file was produced, for example: set
When no option is used, the jmap command prints shared object
mappings. For each shared object loaded in the target JVM, the
start address, size of the mapping, and the full path of the
shared object file are printed. This behavior is similar to the
Oracle Solaris pmap utility.
-dump:[live,] format=b, file=filename
Dumps the Java heap in hprof binary format to filename. The live
suboption is optional, but when specified, only the active
objects in the heap are dumped. To browse the heap dump, you can
use the jhat(1) command to read the generated file.
Prints information about objects that are awaiting finalization.
Prints a heap summary of the garbage collection used, the head
configuration, and generation-wise heap usage. In addition, the
number and size of interned Strings are printed.
Prints a histogram of the heap. For each Java class, the number
of objects, memory size in bytes, and the fully qualified class
names are printed. The JVM internal class names are printed with
an asterisk (*) prefix. If the live suboption is specified, then
only active objects are counted.
Prints class loader wise statistics of Java heap. For each class
loader, its name, how active it is, address, parent class
loader, and the number and size of classes it has loaded are
Force. Use this option with the jmap -dump or jmap -histo option
when the pid does not respond. The live suboption is not
supported in this mode.
Prints a help message.
Prints a help message.
Passes flag to the Java Virtual Machine where the jmap command