An easy way to enter the Mustang Regression contest

; Date: Thu Feb 09 2006

Tags: Java

Let me give y'all an interesting hint on entering the ( regression contest ... Suppose your application has a unit-test suite ... Simply run your test suite on a Tiger build (1.5 update 6 is the latest) and then on a Mustang build ( ( JDK 6 build 70 is the latest) and compare the results.

If every test gives the same result on each then that's wonderful. But if some test gives a different result on Mustang than on Tiger, it's time to roll up your sleeves. Does it show a bug in your application? Or does it show a bug in Java?

If you're satisfied it shows a bug in Java, you've probably found a regression. Again, regressions occur when functionality which used to work in a previous release is broken in a later release. WE WANT TO KNOW ABOUT REGRESSIONS, because we want to fix them before making the final Mustang release.

There's more information about the contest ( here including a link to tne entry page.

Source: (


Uh .. Mustang is certainly not Java, per se. It's just the RI for J2SE 6. cheers, dalibor topic

Posted by: robilad on February 09, 2006 at 05:32 PM

I ran into a source-only regression this afternoon. The problem was that the class had some wildcard imports for stuff like JTable and our custom SwingWorker. When I upgraded to Java 6, the code wouldn't compile because there was a conflict between our SwingWorker and the new javax.swing.SwingWorker. This isn't a breaking regression, but its annoying!

Posted by: jessewilson on February 09, 2006 at 06:44 PM

I cannot enter the contest until someone on the mustang team actually looks up what the word regression really means, and then picks a more rational name for the contest. ;-)

Posted by: cajo on February 09, 2006 at 11:06 PM

Uh... What we mean by regression is, I think, pretty well captured by one of the definitions you linked to: Relapse to a less perfect or developed state

The word regression is widely used within Sun, and I think other software organizations, to mean functionality which used to work, and doesn't work today. Or, a relapse to a less perfect (more buggy) state.

Posted by: robogeek on February 10, 2006 at 10:36 AM

Where can i get the "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy" Files from?

Posted by: dims on February 11, 2006 at 08:36 PM

existing applications are an excellent test, their like giant test suites. I saw something break in my app when I ran it in java 6 but haven't gotten around to seeing why the heck its busted. It may be a jython problem, it may be an API inconsistency. Time will tell. leouser

Posted by: leouser on February 12, 2006 at 12:59 PM

Some material on software engineering that I have defines 'regression testing' as the retesting that becomes mandatory when changes has been made to code that has been tested thoroughly.

Posted by: ovisvana on February 12, 2006 at 10:39 PM

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David Herron : David Herron is a writer and software engineer focusing on the wise use of technology. He is especially interested in clean energy technologies like solar power, wind power, and electric cars. David worked for nearly 30 years in Silicon Valley on software ranging from electronic mail systems, to video streaming, to the Java programming language, and has published several books on Node.js programming and electric vehicles.