Chapter 28. Developing a Consumer From a WSDL Contract

Abstract

One way of creating a consumer is to start from a WSDL contract. The contract defines the operations, messages, and transport details of the service on which a consumer makes requests. The starting point code for the consumer is generated from the WSDL contract. The functionality required by the consumer is added to the generated code.

28.1. Generating the Stub Code

Overview

The cxf-codegen-plugin Maven plug-in generates the stub code from the WSDL contract. The stub code provides the supporting code that is required to invoke operations on the remote service.
For consumers, the cxf-codegen-plugin Maven plug-in generates the following types of code:
  • Stub code — Supporting files for implementing a consumer.
  • Starting point code — Sample code that connects to the remote service and invokes every operation on the remote service.

Generating the consumer code

To generate consumer code use the cxf-codegen-plugin Maven plug-in. Example 28.1, “Consumer Code Generation” shows how to use the code generator to generate consumer code.

Example 28.1. Consumer Code Generation

<plugin>
  <groupId>org.apache.cxf</groupId>
  <artifactId>cxf-codegen-plugin</artifactId>
  <version>${cxf.version}</version>
  <executions>
    <execution>
      <id>generate-sources</id>
      <phase>generate-sources</phase>
      <configuration>
        <sourceRoot>outputDir</sourceRoot>
        <wsdlOptions>
          <wsdlOption>
            <wsdl>wsdl</wsdl>
            <extraargs>
              <extraarg>-client</extraarg>
            </extraargs>
          </wsdlOption>
        </wsdlOptions>
      </configuration>
      <goals>
        <goal>wsdl2java</goal>
      </goals>
    </execution>
  </executions>
</plugin>
Where outputDir is the location of a directory where the generated files are placed and wsdl specifies the WSDL contract's location. The -client option generates starting point code for the consumer's main() method.
For a complete list of the arguments available for the cxf-codegen-plugin Maven plug-in see Section E.2, “cxf-codegen-plugin”.

Generated code

The code generation plug-in generates the following Java packages for the contract shown in Example 26.1, “HelloWorld WSDL Contract”:
  • org.apache.hello_world_soap_http — This package is generated from the http://apache.org/hello_world_soap_http target namespace. All of the WSDL entities defined in this namespace (for example, the Greeter port type and the SOAPService service) map to Java classes this Java package.
  • org.apache.hello_world_soap_http.types — This package is generated from the http://apache.org/hello_world_soap_http/types target namespace. All of the XML types defined in this namespace (that is, everything defined in the wsdl:types element of the HelloWorld contract) map to Java classes in this Java package.
The stub files generated by the cxf-codegen-plugin Maven plug-in fall into the following categories:
  • Classes representing WSDL entities in the org.apache.hello_world_soap_http package. The following classes are generated to represent WSDL entities:
    • Greeter — A Java interface that represents the Greeter wsdl:portType element. In JAX-WS terminology, this Java interface is the service endpoint interface (SEI).
    • SOAPService — A Java service class (extending javax.xml.ws.Service) that represents the SOAPService wsdl:service element.
    • PingMeFault — A Java exception class (extending java.lang.Exception) that represents the pingMeFault wsdl:fault element.
  • Classes representing XML types in the org.objectweb.hello_world_soap_http.types package. In the HelloWorld example, the only generated types are the various wrappers for the request and reply messages. Some of these data types are useful for the asynchronous invocation model.