Print heap summary information

Java memory map tool.
More information: <https://docs.oracle.com/javase/7/docs/technotes/tools/share/jmap.html>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

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

click the source code to copy install jmap on any operating system with command-not-found.com