Question

I got this inherited project using Maven/m2e as the build automation tool. All nice & cool except that this project, checked out of SVN as is, is broken… meaning it fails to build, with several duplicate class errors:

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.1:compile (default-compile) on project myproj: Compilation failure: Compilation failure:
[ERROR] \Users\Daniel\workspace\myproj\target\generated-sources\cxf\org\package1\services\ClassA.java:[36,7] duplicate class: org.package1.services.ClassA

Now, it’s true that ClassA exists in the build environment 3 times:

c:/Users/Daniel/workspace/myproj/src/main/java/org/package1/services/ClassA.java
c:/Users/Daniel/workspace/myproj/src/main/java/org/package1/www/services/ClassA.java
c:/Users/Daniel/workspace/myproj/target/generated-sources/cxf/org/package1/services/ClassA.java

But they belong to different packages:

• package org.package1.services;
• package org.package1.www.services;

So, why would the compiler complain about a duplicate class?

(Or is it Maven that’s complaining?)

I am not familiar with the design considerations of the original author, so any idea how to resolve these duplicates would be much appreciated.

Answer 1

You’ve got three classes, in two packages. Therefore two of the classes are in the same package. These two files:

.../myproj/src/main/java/org/package1/services/ClassA.java
.../myproj/target/generated-sources/cxf/org/package1/services/ClassA.java

… are both contributing org.package1.services.ClassA (which is the fully-qualified class name the compiler is complaining about, note). It’s not clear which one you should be using, based on the information you’ve given.