Setting up the Java client should be relatively trouble free if you have otherwise installed Maven correctly on your system. Unless you have specific requirements that require changes to the client code, you should be able to simply run the following command from the Java client code folder:

mvn clean install

This will build the Java client and install it in your Maven repository. If you run this command again, it will recompile the Java client and update the copy in the repository. Remember to do this, if you need to make changes to the client later.

Most of the Samples will require arguments to run properly, so if you wish to run them from your IDE and not from a .jar file at the command line, then you need to supply the necessary arguments to the project setup.