Java Project Layout - Best Practices

Simple Project

• project-name
• trunk
• src...
• pom.xml
• branches
• branch-abc
• src...
• pom.xml
• tags...

 Multi-Module Project

• project-name 
• project-name-parent
• pom.xml - defines all modules that are part of the project
• module 1 
• trunk
• src...
• pom.xml - points to the parent pom.xml
• branches
• tags
• module 2
• trunk
• src...
• pom.xml - points to the parent pom.xml
• branches
• tags
• module ...

 The key point is that the parent folder doesn't define the parent project, but is just a container for the parent and the children-modules.

Advantages:

• Nicely groups the modules under one folder.
• Allows to build the whole project by calling "mvn clean install" from parent's folder.
• Keeps the SVN (and/or Git) operations simple, unlike the layout where the project-name-parent is the parent folder.