How do I get Eclipse to resolve classes generated with Maven 2?

Question

I\'m using Google Protocol Buffers to generate some Java classes for my project. Using Maven 2 and its \"antrun\" plugin, these classes are freshly generated before compile,

Answer 1

How can I get IDE support (code completion etc.) for the generated code?

Typically I would add the m2e lifecycle-mapping plugin to the pom.xml file as described in @koppor's answer. However adding per-eclipse code to my pom.xml files is not an option at work which is mostly an IntelliJ shop.

My solution first adds the build-helper-maven-plugin to the pom.xml which works fine from the command line but not in eclipse.

    org.codehaus.mojo
    build-helper-maven-plugin
    
        
            generate-sources
            
                add-source
            
            
                
                    ${project.build.directory}/generated-sources/
                
            
        
    

To fix eclipse I installed the Apt M2E Connector from the Eclipse Marketplace. I think things started working right after I restarted and then rebuilt all of my projects. I now see the following in my source dirs:

src/main/java
target/generated-sources
...

Feature!