Java: unresolved compilation issue

Question

What are the possible causes of java.lang.Error: Unresolved compilation problem?

Additional Information:

I saw this after copying a set of updated JAR files from the assembly on top of the existing JARs and restarting the application. JARs are created using the Maven build process.

I would expect to see LinkageErrors or ClassNotFound errors if the interfaces have changed. The above error indicates a lower level problem.

A clean rebuild and redistribution fixed the problem. Can this error indicate a damaged JAR?

Answer 1

(rewritten 2015-07-28)

The default behavior of Eclipse when compiling code with errors in it is to generate byte code that throws the exception you see. This is possible because Eclipse uses its own built-in compiler instead of javac from the JDK, which uses Apache Maven. If you use Eclipse in a Maven project, with which you also work with the mvn command line mvn , this can happen.

Correction - Correct errors and recompile before restarting.

The parameter is marked with a red field for this screendump:

Answer 2

try to clear the eclipse project

Answer 3

Compiled classes can be recompiled from the source with new banks.

Try running "mvn clean" and then rebuild

Answer 4

you are just trying to clear maven with command

 mvn clean 

and after that the next command

 mvn eclipse:clean eclipse:eclipse 

and rebuild your project ....

Answer 5

I had this error when I used a startup configuration that had an invalid class path. In my case, I had a project that originally used Maven, and thus, in the startup configuration there was a Mpath element of the Maven class. Later, I changed the project to using Gradle and removed the Maven class path from the project class path, but the launch configuration still used it. I got this error while trying to run it. Project cleanup and restoration did not resolve this error. Instead, edit the startup configuration, delete the project class path element, and then add the project back to the user entries in the class path.

Answer 6

I got this error several times and tried my best to work. Finally, I deleted the launch configuration and added the default entries again. It worked beautifully.

Answer 7

The main part correctly answered Thorbjorn Ravn Andersen.

This answer attempts to shed light on the remaining question: how can a class file with errors get into the bank?

Each assembly (mvn & javac or eclipse) signals in its specific way when it gets into a compilation error and refuses to create a Jar file (or at least warn you). The most likely reason for silently receiving class files with errors in the bank is the simultaneous operation of Maven and Eclipse.

If you have Eclipse open when you run the mvn build, you must disable Project > Automatically create until mvn completes.