hat

	NOTE: Beginning with JDK 6.0, hat is replaced with jhat. For information on jhat, refer to the jhat section in this document.

The hat tool is a third-party tool that can be used for heap analysis. It starts a Web server on a binary-format heap dump file produced by one of the heap dump options such as -XX:+HeapDumpOnCtrlBreak or -Xrunhprof:heap=dump,format=b.

The following example shows how to use hat. The first command generates a binary heap dump file. The second command executes hat on the binary heap profile.

$ java -Xrunhprof:heap=dump,format=b MyApp  

$ hat -port=7002 java.hprof

The hat tool sets up an http server on the specified port. It can then be accessed by bringing up the default page in a Web browser, for example, http://<hostname.domain>:7002. If you run hat on the same system as the browser, the server can be accessed by navigating to the URL http://<hostname.domain>:7002.

For more information on hat, refer to the following website:

https://hat.dev.java.net

For invocation details, refer to:

https://hat.dev.java.net/doc/README.html