Skip to main content

JT Harness has moved to an OpenJDK project and is no longer being maintained here! Please visit and bookmark our new community location:

The JT harness is based on Oracle's JavaTest harness. The JT harness is a general purpose, fully-featured, flexible, and configurable test harness very well suited for most types of unit testing. Originally developed as a test harness to run TCK test suites, it has since evolved into a general purpose test platform.

The JT harness:

  • Is designed to configure, sequence, and run test suites that consist of many (100,000 or more) discrete, independent tests. It is especially good at testing APIs and compilers.
  • Can be used to run tests on all of the Java platforms, from the Java Card platform, to the Java Platform, Enterprise Edition ("Java EE").
  • Enables you to create test suites that are self-contained products that customers can easily configure and run.

For more information read the JT harness whitepaper (PDF), and run the JT Harness Tutorial.

JT harness technology is being opened in order to develop a community that will improve it, further its development, and use it to develop test suites. We encourage you to browse, download, contribute, and get involved.

News and Announcements

JTHarness Moved to OpenJDK! (March 2014))
JTHarness 4.4.1 Maintenance Release (December 21, 2011)
The JT harness 4.4.1 release is a maintenance release. Release 4.4.1 fixes bugs and includes the following notable changes:
  • Makes the "Report Converter" tool easier to use
  • Improves the speed of loading the ResultCache file
  • Shortens harness start-up time
  • Allows known test execution ordering
  • Adds new "Save view filter" settings
  • Improves COF functionality

JT harness 4.4.1 is compatible with JT harness 4.4. For more information, see the release notes on the download page.

JTHarness 4.4 Feature Release (June 24, 2011)
The JT harness 4.4 release is a feature release. It fixes bugs and it contains the following notable changes:

  • Known failures lists - The known failures list (KFL) allows you to specify one or more files that contain the names of tests that are known to result in a Failed status when executed. When you supply this list of tests to the harness, it can generate an HTML report that includes a section that can help you identify tests that report an unexpected result.
  • Case-sensitive exclude lists - Historically the matching of test names in an exclude list is case-insensitive, although case is preserved by the harness internally. Matching can now be case sensitive if the javatest.caseSensitiveJtx system property is set to "true".

JT harness 4.4 is compatible with JT harness 4.3. For more information, see the release notes on the download page.

The JTHarness project moved to Kenai (January 27, 2011)


Last Update: 12/21/11



Quick Links

For test suite developers:

For JT harness contributors: Project documentation: Blogs:

Related Projects and Links

This section contains links to technologies and blogs that are related to the JT harness technology.

JavaTest Harness

If you are interested in Oracle's commercial version of this product, please see the JavaTest harness page on

JT Harness Extensions

ME Framework The ME Framework is an open source set of JT harness plugins that supports the Java ME platform. Test suite architects use the JT harness and the ME Framework to construct test suites for Java ME technologies.
jtreg The jtreg test harness is used by the JDK test framework. This framework is intended primarily for regression tests. It can also be used for unit tests, functional tests, and even simple product tests.


Java Compatibility Tools This blog provides topics of general interest for people writing tools to test Java platform compatibility and conformance.
Jonathan Gibbons Jon was the lead developer for the JavaTest harness through the release of version 3.1. He currently works on the javac project where as part of his responsibilities he works on the the JDK regression test harness (jtreg). The jtreg test harness is based on the JavaTest harness.

Please Confirm