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This revision made October 25, 2011 22:29, by rwarburton
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The LJC is getting involved in JSR-310 as we believe it's a vital technology for the Java language as software increasingly needs to be date, time and time zone aware in a safe immutable manner.

JSR in a Nutshell

Date and Calendar do not provide adequate functionality for day to day Java developers. JSR-310 addresses this with an implementation based on hard won lessons from JodaTime. For more information on JSR-310 please see the links below and this London Java Community Blog Post

LJC Goals

  1. To assist the threeten project in meeting the Technology Compatibility Kit (TCK) requirements of this JSR, a major milestone to having JSR-310 accepted as part of the Java language.
  2. Promote the ThreeTen implementation and provide pathways for members to get involved in either writing tests on the TCK project or getting involved in the ThreeTen implementation.

LJC Volunteers

We are looking for volunteers within the London Java Community and beyond to help us with our efforts, please contact either of the leads below if you are interested.

Proposed TCK Strategy

  1. Provide a method of running a TCK test suite against an arbitrary jar.
  2. Provide a method of specifying which TestNG tests are part of the TCK.
  3. Specify TestNG tests that are TCK appropriate from the current testsuite.
  4. Write any additional tests that are necessary in order to completely specify the API (It might be the case that this isn't necessary since you already have a lot of tests and test coverage)

Step 1

Source code is available at GitHub and we intend to continue development in the open. We've added a new ant target for testing TCK acceptance. So if you've compiled the latest version of the existing source code, then in order to run the TCK against it you would execute:

   ant -Dtck.implementation=build/threeten-0.6.3.jar tck

You can substitute any arbitrary jar as the 'tck.implementation' variable and it tests against the classes in that jar.

Step 2

We are using TestNG's group feature to specify what tests we want to use as part of the TCK. Currently the 'tck' ant target, only runs tests that are annotated as being part of the 'tck' group from the existing ThreeTen unit tests. So if you want to make a unit test part of tck acceptance you annotated it with:


We've currently annotated a single test with the annotation, but that's just to make sure that it works, rather than a comment on what is tck-appropriate or not.

The next steps will be to work on adding the annotation to tests which are TCK, and either removing or adapting tests which are implementation specific. There is no doubt also going to be the scope to write more tests for the TCK. James and Richard will work on creating a document that will be hosted on this Wiki to track the tests that people are working on within the next few weeks.

Some Legal information on submitting to the TCK

Please note that to submit work to the JCP you will need to have a JSPA countersigned by your employer for legal reasons. The LJC/JCP is currently working on providing some guidance on this, but until then the full detail is here.

Further links and information

Please Confirm