how to fetch the function names, input and output parameters from a WSDL file using java code

I am new to web services. I have been given a task to write a java code to fetch all the method names, input and output parameters from WSDL file and how to provide the input to the web service.

I ransacked google, but did not find anything worth. So if any one can provide me with the code or any sites which can help me then I am so greatfull.