Java web service client

[chester1908]

Hello all. I started out yesterday trying to understand the point of webservices and how to use them. I found countless tutorials but most of them seemed not enough for what i need to understand or outdated or not "manual enough" so i'd do it myself and get it.
IDE is eclipse,tomcat server. What i need to do is make a java program used as webservice.
I create a dynamic web project write down a simple java class having one method getCall(int) which takes an int and returns a random with 0-int.
Question1: the wsdl file is supposed to be the class implementation?What exactly is it?
Now i can make an "auto" test client (eclipse's->file->new web service client-> test)
and verify it works.
Q2: How do i access that from a separate java application?
Q3: one of the tutorials i found mentioned creating and using stub. I found "generate client" copied the class in the package and wrote a new class making an instance of the stub and using getCall() but it didn't work. Now stuck.
Im really confused about how a client java program can have access directly to service,how are stubs used...any info would be great!