How to implement a JSR Specification

问题:

I'm considering implementing one or two JSR APIs. I have not yet read the entire specification (the plan is to read them as I code the implementation) but I am very familiar with them. I have read that the JSR process includes implementing a Test Compatibility Kit (TCK) for testing said JSR implementations.

Before I start writing a bunch of unit tests to verify the correctness/completeness of my implementation I would really like to use this TCK but I have no idea if it is available for me. After downloading all files and googling around I could not find anything that could be defined as a TCK for the given JSR.

So my question is basically: What steps do I need to do in order to produce my own implementation of a JSR spec and how do I verify that I have indeed done so.

For what it's worth, I am considering implementing JSR-168 and JSR-286, but I think that is not relevant for this question.

回答1:

What you may need to do, is to contact the spec lead for the given JSR. They can give you more information on obtaining a TCK.

It may be that you have to pay a license to obtain access to the TCK. Certainly with the Java SE specification, Sun does indeed charge a license fee for the TCK, unless you qualify as a non-profit organization to receive it for free.

That said, I believe it varies from JSR to JSR, so as I said above, the best bet is to contact the JSR spec lead.

回答2:

Wow, this is a very ambitious project, usually taken over by companies or big open source teams. If you are determined enough to do it, I recommend that you have a look at some open source implementations. The mentioned JSRs are implemented by Pluto. It may worth to have a look at the source distribution.

回答3:

Apologies in davance for the worst case scenario I'm going to present.

From having done this quite a few times before, I strongly advise not writing a single line of code before you have read not only the spec but any kind of e-mail archive from the JSR expert group.

JSR specifications are usually full of ambiguity and can be interpreted in a number of different ways. Going through it in a very methodical way will let you ask relevant questions to the expert group soon enough before it disbands and becomes unresponsive, hopefully.

The TCK is typically a set of tests that does not ensure your implementation even remotely works, it just says you are a legal implementation of the specifications.

TCKs are typically too expensive for a single individual to buy.

Obivously, the way to implement the JSR will depend on what operating system and what virtual machine you are targetting. The nicer JSRs are usually the ones that can be implemented in pure Java.

Good luck!

回答4:

Why do you want to implement a spec if there is already a working implementation ? Seems like a lot of needless work for little benefit...