Eclipse settings affect Maven command-line build?

Question

Most of our projects are built with Maven, and some of them use classes in the com.sun package. That's a bad practice, but there's not much I can do about it.

For a while this didn't seem to be a big problem. Then, at some point, builds started failing for me with errors such as the following:

java.lang.Error: Unresolved compilation problems:
        Access restriction: The type TextSerializer is not accessible due to res
triction on required library C:\Program Files\Java\jre1.5.0_15\lib\rt.jar

That's fair enough, but I couldn't for the life of me figure out how to turn off that check. The builds were failing both from the command line and from within Eclipse, so I assumed it must be some Maven setting.

Eventually I figured out that the problem was somehow with Eclipse. I went to Preferences > Java > Compiler > Errors/Warnings > Deprecated and restricted API and changed 'Forbidden Reference' to 'Warning'. Thereafter, my builds started working. This is completely incomprehensible to me, because I was getting the errors when building from the command line.

Can someone please explain to me how an Eclipse setting can somehow affect the behaviour of a build from the command line?!

Answer 1

My colleague helpfully pointed out that mvn clean install fixes the problem. Eventually we worked out that (M2)Eclipse is leaving some partially compiled classes in the target directory, and of course vanilla Maven doesn’t know that it should recompile those classes. I’m a little bit annoyed about this. It should be obvious to anyone that leaving broken output in the target directory is bound to subtly pollute later builds.

Answer 2

yeah the "clean" is the key Note however that it's not just that it has failure builds around--somehow or other m2eclipse just leaves junk behind, even if it compiles right.

This can also cause things like

java.lang.Error: Unresolved compilation problem:

from the command line

Answer 3

I am seeing similar issues using Netbeans (6.9.1) with a Maven project. mvn clean resolves the problem.