I downloaded code from https://github.com/nidi3/graphviz-java and ran
'mvn clean install'.
It is stuck after this output
[INFO] --- maven-compiler-plugin:3.1:testCompile (default-testCompile) @ graphviz-java --- [INFO] Changes detected - recompiling the module! [INFO] Compiling 10 source files to D:\graphviz-java-master\target\test-classes
my java setting is : Java HotSpot(TM) 64-Bit Server VM warning: ignoring option MaxPermSize=512M; support was removed in 8.0