I am building an app and I am suffering "surprises" because jars are changed very often. Then could be possible using Maven or other building tool set the app once and forget about updates? I mean I want that the building tool update all the dependencies for me.
Yes, that's what Maven, and a repository manager such as Nexus, will do for you. As teams build their JARs, they are placed into Nexus and when you build with Maven you will automatically get the latest JARs (either because the JARs are defined as SNAPSHOTs, or you specified a version range when you defined the dependency on the JARs))