jhat - Starting Web Server on a Heap Dump File

This section provides a tutorial example on how to start 'jhat' as a Web server on a Java heap dump file allowing you to browse Java heap objects.

Warning: "jhat" has been discontinued since JDK 9. But if you still have JDK 1.8 installed, you can continue to use it to browser heap dump files generated by JDK 9 and JDK 10.

In an earlier tutorial example, I created a Java heap dump file with the "jmap" tool on my GarbageCollection.java program. The heap dump file is named as GarbageCollection.map. Now I want to try to run the "jhat" Web server on this dump file and browse the heap dump with a Web browser.

1. Run the "jhat" command with default options:

C:\herong>\Progra~1\java\jdk1.8.0\bin\jhat GarbageCollection.map

Reading from GarbageCollection.map...
Dump file created Jan 1 00:08:10 EDT 2008
Snapshot read, resolving...
Resolving 67324 objects...
Chasing references, expect 13 dots.............
Eliminating duplicate references.............
Snapshot resolved.
Started HTTP server on port 7000
Server is ready.

2. Run a Web browser with http://localhost:7000. The "jhat" heap dump file server page shows up:

jhat Heap Dump File Server
jhat Heap Dump File Server

See next sections on how to use "jhat" Web server to browse heap objects.

Last update: 2018.

Table of Contents

 About This Book

 Java Tools Terminology

 Java Tools Included in JDK

 javac - The Java Program Compiler

 jar - The JAR File Tool

 jlink - The JRE Linker

 jmod - The JMOD File Tool

 jimage - The JIMAGE File Tool

 java - The Java Program Launcher

 jdb - The Java Debugger

 jcmd - The JVM Diagnostic Tool

 jconsole - Java Monitoring and Management Console

 jstat - JVM Statistics Monitoring Tool

JVM Troubleshooting Tools

 JVM Troubleshooting Tools in JDK

 jinfo - VM Option Value Checker

 jinfo - Changing HotSpot VM Option

 jstack - Stack Tracer to Generate Thread Dump

 What Is a Thread Dump?

 Java Thread Deadlock Demo Program

 jstack - Detecting Java Thread Deadlocks

 jmap - JVM Heap Dump Tool

 Printing Histogram of Java Object Heap

 jmap - Generating Heap Dump File

 jhat - Java Heap Analysis Tool

jhat - Starting Web Server on a Heap Dump File

 Listing Instance Counts of All Classes

 Browsing Object Instance Values

 Object Query Language (OQL)

 Searching for Instances with OQL Statements

 jvisualvm (Java VisualVM) - JVM Visual Tool

 jmc - Java Mission Control

 javap - The Java Class File Disassembler

 keytool - Public Key Certificate Tool

 jarsigner - JAR File Signer

 jshell - Java Language Shell

 native2ascii - Native-to-ASCII Encoding Converter

 Outdated Tutorials

 References

 Full Version in PDF/EPUB