Java Web Services: Up and Running, 2nd Edition

Clients Against the RandService

The claim that SOAP-based services are language-neutral needs to be taken on faith a bit longer. The first client against the RandService is in Java but the two thereafter are in C# and Perl. Starting with a Java client will help to clarify how the critical service contract, the WSDL document, can be put to good use in writing a client. The WSDL will be studied in detail, but putting the WSDL to work first should help to motivate the detailed study.

A Java Client Against the RandService

Recall the XML Schema (see Example 4-3) that the Endpoint publisher generates dynamically when the RandService is published. The publisher likewise generates a WSDL, which can be requested as follows:

% curl http://localhost:8888/rs?wsdl

JDK 1.6 and greater ship with a utility, wsimport, that uses a WSDL to generate Java classes in support of programming a client against the service described in the WSDL. Here is how the utility can be used in the current example:

% wsimport -p client -keep http://localhost:8888/rs?wsdl

The -p flag stands for “package”: the utility creates a directory named client and puts the generated Java code in this directory/package. The -keep flag generates source (.java) as well as compiled (.class) files; without this flag, only compiled files would be in the client directory. Sixteen files are generated in total, half source and half compiled. Among these are files with names such as Next1 and Next1Response, the very names of the classes generated ...