jmap Command Examples

Java memory map tool. More information: https://docs.oracle.com/en/java/javase/20/docs/specs/man/jmap.html.

• Print shared object mappings for a Java process (output like pmap):

jmap {{java_pid}}

• Print heap summary information:

jmap -heap {{filename.jar}} {{java_pid}}

• Print histogram of heap usage by type:

jmap -histo {{java_pid}}

• Dump contents of the heap into a binary file for analysis with jhat:

jmap -dump:format=b,file={{path/to/file}} {{java_pid}}

• Dump live objects of the heap into a binary file for analysis with jhat:

jmap -dump:live,format=b,file={{path/to/file}} {{java_pid}}