This is a known bug in eclipse and as such has replicated into Spring STS. It is caused by the maven-jar plugin. This can be resolved by downloading and using the very latest version. Currently STS 3.8.2.RELEASE
ctrl-F to open File/Replace Dialog check Regular Expressions Find: ^[\t }*@.*$\R Replace \with: <leave blank> Click Replace All
Window -> Preferences -> General -> Search uncheck Reuse editors to show matches
Start Eclipse Help -> Install New Software Work With: http://download.jboss.org/drools/release/5.5.0.Final/org.drools.updatesite/ click the “Add” button Name: Drools Check the Drools and jBPM checkbox and follow the instructions to get it installed.