I’m using SonarJava 5.9.1 (build 16423)
Activating the Debug Log I found out that there are tons of jar files analyzied for the classpath.
I managed it to decrease the time dramatically (7 Minutes!) by removing the libraries configuration:
sonar.java.libraries=../**/*.jar
sonar.java.test.libraries=../**/*.jar
Maybe I need to think about a more precise inclusion of dependencies.
Anyway: Thanks for the help - with 7 Minutes (or less) the Incremental Analysis is not that important anymore.