You need to add your resources folder to your java build path:
- Right Click on your project in the Project Explorer
- properties -> click Java Build Path -> select "Source" tab
- click "Add Folder..." and add your src/main/resources folder
update: if you are using the sbt eclipse plugin you can configure it to automatically add the resources folder to the classpath :
(from: sbteclipse docs)
EclipseKeys.createSrc := EclipseCreateSrc.Default + EclipseCreateSrc.Resource