Scala compile message – Class file or Jar is broken

Sometimes when compiling my Scala code, the compiler output may need a little bit of help in sorting out what’s the real issue.

For example, when I compiled today I received the following error:

[scalac] error: error while loading DefaultHttpClient, class file 'C:\A_OpenSource\WicketNotesApp\lib\httpclient-4.0.jar(org/apache/http/impl/client/DefaultHttpClient.class)' is broken
[scalac] (class net.jcip.annotations.ThreadSafe not found.)

[scalac] error: error while loading AbstractHttpClient, class file 'C:\A_OpenSource\WicketNotesApp\lib\httpclient-4.0.jar(org/apache/http/impl/client/AbstractHttpClient.class)' is broken
[scalac] (class net.jcip.annotations.ThreadSafe not found.)

And my instinct tells me to focus on the jar file or the class file and in this case, “DefaultHttpClient.class” or “AbstractHttpClient.class” or “httpclient-4.0.jar”. There’s noting wrong with your jar file or the Java class. The actual problem is in the next line, namely “class net.jcip.annotations.ThreadSafe not found.” It’s a class-not-found error.

So if you encounter a “broken” error when compiling Scala – the following line after the broken message can help you find the real error. It can save you a whole lot of head-aches and chasing the wrong tail.

If you find this article useful, consider signing up for my RSS feed or Email Newsletter. See links on the right side.

Image may be NSFW.
Clik here to view.

Image may be NSFW.
Clik here to view.