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 to JDK 12.

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 heap dump first 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.



 

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

 jdeps - The Java Class Dependency Analyzer

 jdeprscan - The Java Deprecated API Scanner

 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

 jhsdb - The Java HotSpot Debugger

 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