jmap

Introduction

You can run the jmap command to view object statistics in the Java heap.

Installation Mode

Use OpenJDK to install this tool. For BiSheng JDK, it is a built-in tool.

Usage

• If a Java environment is configured, you can directly run the jmap command.
• If no Java environment is not configured, run the ps -ef | grep java command to find the Java process. Then, switch to the JDK bin directory and run the ./jmap command.

  Syntax:

  1	jmap -histo:live $pid

  Common parameters are as follows:

  Parameter	Description
  -heap	Displays Java heap details.
  -histo[:live]	Displays information about live objects in the heap.
  -dump	Generates a heap dump snapshot.
  -finalizerinfo	Displays the information about the objects to be terminated.
  -clstats	Displays the class loader information.