The easiest and a more suitable way of creating a web service is to start from the WSDL document. This is the method most followed when it comes to most of the enterprise level applications. As enterprise level applications usually have well defined business scenarios and corresponding business contracts, which can be presented in the form of a WSDL document, it makes sense to start from there. The point to note here is that once the client and the producer (service) have the WSDL document, it acts as a contract according to which the development should take place.
Axis2 has inbuilt support for the generation of service and client code, once you have the WSDL document. So in this case, as a service author, you only need to do the following:
Generate the service code (service skeleton).
Fill in the service skeleton according to the business logic.
Run the generated Ant build file.
Deploy the service archive file created by Ant into your application...