Creating a Java Web Service Client from a WSDL

In my previous post, I discussed the creation of a web service. That's all good and dandy, but can be rather boring because we can't do anything with it other than touch it with a web browser and see a bunch of XML. Although this example is very specific to the web service created prior, the concepts can be applied to most web services.

Generating Classes from a WSDL

This project is different than some because it starts with a build.xml. Within it is the necessary task to generate *.java files we will use later for communicating with the web service.

<?xml version="1.0"?>
<!--build.xml WebService Client Example by Jason Staten-->
<project basedir="." default="client" name="MathServiceExample">
  <property environment="env"/>
  <property name="lib.home" value="${env.JAXWS_HOME}/lib"/>
  <property name="build.home" value="${basedir}/build"/>
  <property name="build.classes.home" value="${build.home}/classes"/>
  <path id="jaxws.classpath">
    <pathelement location="${java.home}/../lib/tools.jar"/>
    <fileset dir="${lib.home}">
      <include name="*.jar"/>
      <exclude name="j2ee.jar"/>
    </fileset>
  </path>
  <taskdef name="wsimport" classname="com.sun.tools.ws.ant.WsImport">
    <classpath refid="jaxws.classpath"/>
  </taskdef>
  <target name="setup">
    <mkdir dir="${build.home}"/>
    <mkdir dir="${build.classes.home}"/>
  </target>
  <target name="generate-client">
    <wsimport debug="true"
              verbose="${verbose}"
              keep="true"
              sourcedestdir="${basedir}/src"
              package="com.jstaten.webService.client.generated"
              wsdl="http://localhost:7070/MathExample/MathService?wsdl"
              xnocompile="true">
</wsimport>
  </target>
  <target name="client" depends="generate-client,setup">
    <javac  fork="true"
            srcdir="${basedir}/src"
            destdir="${build.classes.home}"
            includes="**/client/**,**/common/**">
      <classpath refid="jaxws.classpath"/>
    </javac>
  </target>
  <target name="clean">
    <delete dir="${build.home}" includeEmptyDirs="true"/>
  </target>
</project>

There are two key parts to this build file, the taskdef that declares what the wsimport tag actually is and the task generate-client that uses wsimport to generate the java that provides an interface to the webservice. If you look within your src directory, you will now notice that there are now *.java files for use with your own code. Let's get to using it.

Writing the Client

package com.jstaten.webService.client;
import com.jstaten.webService.client.generated.*;
public class MathClient {
    public static void main(String[] args) {
        MathExampleImpl port = new
        MathExampleImplService().getMathExampleImplPort();
        int addA = 10;
        int addB = 20;
        float multiplyA = 30;
        float multiplyB = 20.59f;

        System.out.println(addA + " + " + addB + " =");

        System.out.println(port.addInts(addA, addB));
        System.out.println(multiplyA + " * " + multiplyB + " =");
    }
}

The code is relatively straightforward. We make an import call to the generated classes. Next we create a new MathExampleImpl object that is our interface to the webservice. Finally, we run a few test methods on it and return the result to the console so we can see the result.

Build the Client

<?xml version="1.0"?>
<target name="client" depends="generate-client,setup">
  <javac fork="true"
         srcdir="${basedir}/src"
         destdir="${build.classes.home}"
         includes="**/client/**,**/common/**">
    <classpath refid="jaxws.classpath"/>
  </javac>
</target>

Adding the above into your build file within the project element will allow you to build the client. Essentially it's just a javac call with some arguments. Having it in the build file allows you to not have to type all that stuff into the command line every time you compile - much more convenient. Run the compiled client and you should now see the results you printed to the console. Next time, doing the same thing via .NET in C

Originally Written 12/2/2008