Getting Started With WebLogic Web Services Using JAX-WS

      

Invoking Web Services

The following sections describe how to invoke WebLogic Web Services:

The following sections do not include information about invoking message-secured Web Services; for that topic, see “Updating a Client Application to Invoke a Message-Secured Web Service” in Securing WebLogic Web Services.

 

Overview of Web Services Invocation

Invoking a Web Service refers to the actions that a client application performs to use the Web Service. Client applications that invoke Web Services can be written using any technology: Java, Microsoft .NET, and so on.

There are two types of client applications:

The sections that follow describe how to use Oracle's implementation of the JAX-WS specification to invoke a Web Service from a Java client application. You can use this implementation to invoke Web Services running on any application server, both WebLogic and non-WebLogic. In addition, you can create a stand-alone client application or one that runs as part of a WebLogic Server.

WebLogic Server includes examples of creating and invoking WebLogic Web Services in the WL_HOME/samples/server/examples/src/examples/webservices directory, where WL_HOME refers to the main WebLogic Server directory. For detailed instructions on how to build and run the examples, open the WL_HOME/samples/server/docs/index.html Web page in your browser and expand the WebLogic Server Examples->Examples->API->Web Services node.

 

Invoking a Web Service from a Stand-alone Client: Main Steps

The following table summarizes the main steps to create a stand-alone client that invokes a Web Service. See also Using a Stand-Alone Client JAR File When Invoking Web Services.

It is assumed that you use Ant in your development environment to build your client application, compile Java files, and so on, and that you have an existing build.xml file that you want to update with Web Services client tasks. For general information about using Ant in your development environment, see Creating the Basic Ant build.xml File. For a full example of a build.xml file used in this section, see Sample Ant Build File for a Stand-Alone Java Client.

Table 6-1 Steps to Invoke a Web Service from a Stand-alone Client
# Step Description
1 Set up the environment. Open a command window and execute the setDomainEnv.cmd (Windows) or setDomainEnv.sh (UNIX) command, located in the bin subdirectory of your domain directory. The default location of WebLogic Server domains is BEA_HOME/user_projects/domains/domainName, where BEA_HOME is the top-level installation directory of the Oracle products and domainName is the name of your domain.
2 Update your build.xml file to execute the clientgen Ant task to generate the needed client-side artifacts to invoke a Web Service. See Using the clientgen Ant Task To Generate Client Artifacts.
3 Get information about the Web Service, such as the signature of its operations and the name of the ports. See Getting Information About a Web Service.
4 Write the client application Java code that includes code for invoking the Web Service operation. See Writing the Java Client Application Code to Invoke a Web Service.
5 Create a basic Ant build file, build.xml. See Creating the Basic Ant build.xml File.
6 Compile and run your Java client application. See Compiling and Running the Client Application.

 

Using the clientgen Ant Task To Generate Client Artifacts

The clientgen WebLogic Web Services Ant task generates, from an existing WSDL file, the client artifacts that client applications use to invoke both WebLogic and non-WebLogic Web Services. These artifacts include:

For additional information about the clientgen Ant task, such as all the available attributes, see “Ant Task Reference” in the WebLogic Web Services Reference.

Update your build.xml file, adding a call to the clientgen Ant task, as shown in the following example: 

  <taskdef name="clientgen"

     classname="weblogic.wsee.tools.anttasks.ClientGenTask" />

  <target name="build-client">

     <clientgen

       wsdl="http://${wls.hostname}:${wls.port}/complex/ComplexService?WSDL"

       destDir="clientclasses"

       packageName="examples.webservices.simple_client"

       type="JAXWS"/>

  </target>

Before you can execute the clientgen WebLogic Web Service Ant task, specify its full Java classname using the standard taskdef Ant task.

You must include the wsdl and destDir attributes of the clientgen Ant task to specify the WSDL file from which you want to create client-side artifacts and the directory into which these artifacts should be generated. The packageName attribute is optional; if you do not specify it, the clientgen task uses a package name based on the targetNamespace of the WSDL. The type is required in this example; otherwise, it defaults to JAXRPC.

In this example, the package name is set to the same package name as the client application, examples.webservices.simple_client. If you set the package name to one that is different from the client application, you would need to import the appropriate class files. For example, if you defined the package name as examples.webservices.complex, you would need to import the following class files in the client application: 

import examples.webservices.complex.BasicStruct;

import examples.webservices.complex.ComplexPortType;

import examples.webservices.complex.ComplexService;

The clientgen Ant task also provides the destFile attribute if you want the Ant task to automatically compile the generated Java code and package all artifacts into a JAR file. For details and an example, see “clientgen” in the WebLogic Web Services Reference.

If the WSDL file specifies that user-defined data types are used as input parameters or return values of Web Service operations, clientgen automatically generates a JavaBean class that is the Java representation of the XML Schema data type defined in the WSDL. The JavaBean classes are generated into the destDir directory.

For a full sample build.xml file that contains additional targets from those described in this procedure, such as clean, see Sample Ant Build File for a Stand-Alone Java Client.

To execute the clientgen Ant task, along with the other supporting Ant tasks, specify the build-client target at the command line: 

prompt> ant build-client

See the clientclasses directory to view the files and artifacts generated by the clientgen Ant task.

 

Getting Information About a Web Service

You need to know the name of the Web Service and the signature of its operations before you write your Java client application code to invoke an operation. There are a variety of ways to find this information.

The best way to get this information is to use the clientgen Ant task to generate the Web Service-specific Service files and look at the generated *.java files. These files are generated into the directory specified by the destDir attribute, with subdirectories corresponding to either the value of the packageName attribute, or, if this attribute is not specified, to a package based on the targetNamespace of the WSDL.

You can also examine the actual WSDL of the Web Service; see Browsing to the WSDL of the Web Service for details about the WSDL of a deployed WebLogic Web Service. The name of the Web Service is contained in the <service> element, as shown in the following excerpt of the TraderService WSDL: 

  <service name="TraderService">

    <port name="TraderServicePort"

         binding="tns:TraderServiceSoapBinding">

  ...

    </port>

  </service>

The operations defined for this Web Service are listed under the corresponding <binding> element. For example, the following WSDL excerpt shows that the TraderService Web Service has two operations, buy and sell (for clarity, only relevant parts of the WSDL are shown): 

  <binding name="TraderServiceSoapBinding" ...>

    ...

    <operation name="sell">

    ...

    </operation>

    <operation name="buy">

    </operation>

  </binding>

 

Writing the Java Client Application Code to Invoke a Web Service

In the following code example, a stand-alone application invokes a Web Service operation. The application uses standard JAX-WS API code and the Web Service-specific implementation of the Service interface, generated by clientgen, to invoke an operation of the Web Service.

The example also shows how to invoke an operation that has a user-defined data type (examples.webservices.simple_client.BasicStruct) as an input parameter and return value. The clientgen Ant task automatically generates the Java code for this user-defined data type.

Because the <clientgen> packageName attribute was set to the same package name as the client application, we are not required to import the <clientgen>-generated files. 

package examples.webservices.simple_client;

/**

 * This is a simple stand-alone client application that invokes the

 * the echoComplexType operation of the ComplexService Web service.

 */

public class Main {

  public static void main(String[] args) { 

    ComplexService test = new ComplexService(), 

    ComplexPortType port = test.getComplexPortTypePort();

    BasicStruct in = new BasicStruct();

    in.setIntValue(999);

    in.setStringValue("Hello Struct");

    BasicStruct result = port.echoComplexType(in);

    System.out.println("echoComplexType called. Result: " + result.getIntValue() + ", " + result.getStringValue());

  }

}

In the preceding example:

 

Compiling and Running the Client Application

Add javac tasks to the build-client target in the build.xml file to compile all the Java files (both of your client application and those generated by clientgen) into class files, as shown by the bold text in the following example: 

  <target name="build-client">

    <clientgen

      wsdl="http://${wls.hostname}:${wls.port}/complex/ComplexService?WSDL"

      destDir="clientclasses"

      packageName="examples.webservices.simple_client"

      type="JAXWS"/>

    <javac

      srcdir="clientclasses" 

      destdir="clientclasses"

      includes="**/*.java"/>

    <javac

      srcdir="src" 

      destdir="clientclasses"

      includes="examples/webservices/simple_client/*.java"/>

  </target>

In the example, the first javac task compiles the Java files in the clientclasses directory that were generated by clientgen, and the second javac task compiles the Java files in the examples/webservices/simple_client subdirectory of the current directory; where it is assumed your Java client application source is located.

In the preceding example, the clientgen-generated Java source files and the resulting compiled classes end up in the same directory (clientclasses). Although this might be adequate for prototyping, it is often a best practice to keep source code (even generated code) in a different directory from the compiled classes. To do this, set the destdir for both javac tasks to a directory different from the srcdir directory.

To run the client application, add a run target to the build.xml that includes a call to the java task, as shown below: 

<path id="client.class.path">

    <pathelement path="clientclasses"/>

    <pathelement path="${java.class.path}"/>

</path>

<target name="run" >

    <java 

       fork="true" 

       classname="examples.webServices.simple_client.Main"

       failonerror="true" >

       <classpath refid="client.class.path"/>

</target>

The path task adds the clientclasses directory to the CLASSPATH. The run target invokes the Main application, passing it the URL of the deployed Web Service as its single argument.

See Sample Ant Build File for a Stand-Alone Java Client for a full sample build.xml file that contains additional targets from those described in this procedure, such as clean.

Rerun the build-client target to regenerate the artifacts and recompile into classes, then execute the run target to invoke the echoStruct operation: 

    prompt> ant build-client run

You can use the build-client and run targets in the build.xml file to iteratively update, rebuild, and run the Java client application as part of your development process.

 

Sample Ant Build File for a Stand-Alone Java Client

The following example shows a complete build.xml file for generating and compiling a stand-alone Java client. See Using the clientgen Ant Task To Generate Client Artifacts and Compiling and Running the Client Application for explanations of the sections in bold. 

<project name="webservices-simple_client" default="all">

  <!-- set global properties for this build -->

  <property name="wls.hostname" value="localhost" />

  <property name="wls.port" value="7001" />

  <property name="example-output" value="output" />

  <property name="clientclass-dir" value="${example-output}/clientclass" />

  <path id="client.class.path">

    <pathelement path="${clientclass-dir}"/>

    <pathelement path="${java.class.path}"/>

  </path>

  <taskdef name="clientgen"

    classname="weblogic.wsee.tools.anttasks.ClientGenTask" />

  <target name="clean" >

    <delete dir="${clientclass-dir}"/>

  </target>

  <target name="all" depends="clean,build-client,run" />

  <target name="build-client">

    <clientgen

      wsdl="http://${wls.hostname}:${wls.port}/complex/ComplexService?WSDL"

      destDir="${clientclass-dir}"

      packageName="examples.webservices.simple_client"

      type="JAXWS"/>

    <javac

      srcdir="${clientclass-dir}" destdir="${clientclass-dir}"

      includes="**/*.java"/>

    <javac

      srcdir="src" destdir="${clientclass-dir}"

      includes="examples/webservices/simple_client/*.java"/>

  </target>

  <target name="run" >

    <java fork="true"

          classname="examples.webservices.simple_client.Main"

          failonerror="true" >

      <classpath refid="client.class.path"/>

    </java>

  </target>

</project>

 

Invoking a Web Service from Another Web Service

Invoking a Web Service from within a WebLogic Web Service is similar to invoking one from a stand-alone Java application, as described in Invoking a Web Service from a Stand-alone Client: Main Steps, with the following variations:

This section describes the differences between invoking a Web Service from a client in a Java EE component and invoking from a stand-alone client. It is assumed that you have read and understood Invoking a Web Service from a Stand-alone Client: Main Steps. It is also assumed that you use Ant in your development environment to build your client application, compile Java files, and so on, and that you have an existing build.xml that builds a Web Service that you want to update to invoke another Web Service.

The following list describes the changes make to the build.xml file that builds your client Web Service, which will invoke another Web Service. See Sample build.xml File for a Web Service Client for the full sample build.xml file:

The following list describes the changes make to the JWS file that implements the client Web Service; see Sample JWS File That Invokes a Web Service for the full JWS file example.

 

Sample build.xml File for a Web Service Client

The following sample build.xml file shows how to create a Web Service that itself invokes another Web Service; the relevant sections that differ from the build.xml for building a simple Web Service that does not invoke another Web Service are shown in bold.

The build-service target in this case is very similar to a target that builds a simple Web Service; the only difference is that the jwsc Ant task that builds the invoking Web Service also includes a <clientgen> child element of the <jws> element so that jwsc also generates the required JAX-RPC client stubs. 

<project name="webservices-service_to_service" default="all">

  <!-- set global properties for this build -->

  <property name="wls.username" value="weblogic" />

  <property name="wls.password" value="weblogic" />

  <property name="wls.hostname" value="localhost" />

  <property name="wls.port" value="7001" />

  <property name="wls.server.name" value="myserver" />

  <property name="ear.deployed.name" value="ClientServiceEar" />

  <property name="example-output" value="output" />

  <property name="ear-dir" value="${example-output}/ClientServiceEar" />

  <property name="clientclass-dir" value="${example-output}/clientclasses" />

  <path id="client.class.path">

    <pathelement path="${clientclass-dir}"/>

    <pathelement path="${java.class.path}"/>

  </path>

  <taskdef name="jwsc"

    classname="weblogic.wsee.tools.anttasks.JwscTask" />

  <taskdef name="clientgen"

    classname="weblogic.wsee.tools.anttasks.ClientGenTask" />

  <taskdef name="wldeploy"

    classname="weblogic.ant.taskdefs.management.WLDeploy"/>

  <target name="all" depends="clean,build-service,deploy,client" />

  <target name="clean" depends="undeploy">

    <delete dir="${example-output}"/>

  </target>

  <target name="build-service">

    <jwsc

        srcdir="src"

        destdir="${ear-dir}" >

        <jws

         file="examples/webservices/service_to_service/ClientServiceImpl.java"

         type="JAXWS">

          <clientgen

                wsdl="http://${wls.hostname}:${wls.port}/complex/ComplexService?WSDL"

                packageName="examples.webservices.complex" />

        </jws>

    </jwsc>

  </target>

  <target name="deploy">

    <wldeploy action="deploy" name="${ear.deployed.name}"

      source="${ear-dir}" user="${wls.username}"

      password="${wls.password}" verbose="true"

      adminurl="t3://${wls.hostname}:${wls.port}"

      targets="${wls.server.name}" />

  </target>

  <target name="undeploy">

    <wldeploy action="undeploy" name="${ear.deployed.name}"

      failonerror="false"

      user="${wls.username}"

      password="${wls.password}" verbose="true"

      adminurl="t3://${wls.hostname}:${wls.port}"

      targets="${wls.server.name}" />

  </target>

  <target name="client">

    <clientgen

      wsdl="http://${wls.hostname}:${wls.port}/ClientService/ClientService?WSDL"

      destDir="${clientclass-dir}"

      packageName="examples.webservices.service_to_service.client"

      type="JAXWS"/>

    <javac

      srcdir="${clientclass-dir}" destdir="${clientclass-dir}"

      includes="**/*.java"/>

    <javac

      srcdir="src" destdir="${clientclass-dir}"

      includes="examples/webservices/service_to_service/client/**/*.java"/>

  </target>

  <target name="run">

    <java classname="examples.webservices.service_to_service.client.Main"

          fork="true"

          failonerror="true" >

          <classpath refid="client.class.path"/>

    </java>

  </target>

</project>

 

Sample JWS File That Invokes a Web Service

The following sample JWS file, called ClientServiceImpl.java, implements a Web Service called ClientService that has an operation that in turn invokes the echoComplexType operation of a Web Service called ComplexService. This operation has a user-defined data type (BasicStruct) as both a parameter and a return value. The relevant code is shown in bold and described after the example. 

package examples.webservices.service_to_service;

import javax.jws.WebService;

import javax.jws.WebMethod;

// Import the BasicStruct data type, generated by clientgen and used

// by the ComplexService Web Service

import examples.webservices.complex.BasicStruct;

// Import the JAX-WS Stubs for invoking the ComplexService Web Service.

// Stubs generated by clientgen

import examples.webservices.complex.ComplexPortType;

import examples.webservices.complex.ComplexService;

@WebService(name="ClientPortType", serviceName="ClientService",

            targetNamespace="http://examples.org")

public class ClientServiceImpl {

  @WebMethod()

  public String callComplexService(BasicStruct input, String serviceUrl) 

  {

    // Create service and port stubs to invoke ComplexService

    ComplexService test = new ComplexService(); 

    ComplexPortType port = test.getComplexPortTypePort();

    // Invoke the echoComplexType operation of ComplexService

    BasicStruct result = port.echoComplexType(input);

    System.out.println("Invoked ComplexPortType.echoComplexType." );

    return "Invoke went okay!  Here's the result: '" + result.getIntValue() + ",  " + result.getStringValue() + "'";

  }

}

Follow these guidelines when programming the JWS file that invokes another Web Service; code snippets of the guidelines are shown in bold in the preceding example:

 

Defining a Web Service Reference Using the @WebServiceRef Annotation

The @WebServiceRef annotation enables you to define a reference to a Web Service. For example, in the following sample, a reference to the ComplexService is defined by passing the WSDL of the Web Service to the @WebServiceRef annotation. 

package examples.webservices.service_to_service;

import javax.jws.WebService;

import javax.jws.WebMethod;

import javax.xml.ws.WebServiceRef;

// Import the BasicStruct data type, generated by clientgen and used

// by the ComplexService Web Service

import examples.webservices.complex.BasicStruct;

// Import the JAX-WS interfaces for invoking the ComplexService Web Service.

// Interfaces generated by clientgen

import examples.webservices.complex.ComplexPortType;

import examples.webservices.complex.ComplexService;

@WebService(name="ClientPortType", serviceName="ClientService",

            targetNamespace="http://examples.org")

public class ClientServiceImpl {

    @WebServiceRef()

    ComplexService service;

  @WebMethod()

  public String callComplexService(BasicStruct input)

  {

    // Create service and port stubs to invoke ComplexService

    ComplexPortType port = service.getComplexPortTypePort();

    // Invoke the echoComplexType operation of ComplexService

    BasicStruct result = port.echoComplexType(input);

    System.out.println("Invoked ComplexPortType.echoComplexType." );

    return "Invoke went okay!  Here's the result: '" + result.getIntValue() + ",  " + result.getStringValue() + "'";

  }

}

In the preceding example:

 

Using a Stand-Alone Client JAR File When Invoking Web Services

It is assumed in this document that, when you invoke a Web Service using the client-side artifacts generated by the clientgen or wsdlc Ant tasks, you have the entire set of WebLogic Server classes in your CLASSPATH. If, however, your computer does not have WebLogic Server installed, you can still invoke a Web Service by using the stand-alone WebLogic Web Services client JAR file, as described in this section.

The standalone client JAR file supports basic client-side functionality, such as:

The stand-alone client JAR file does not, however, support invoking Web Services that use the following advanced feature:

To use the stand-alone WebLogic Web Services client JAR file with your client application, follow these steps:

  1. Copy the file WL_HOME/server/lib/wseeclient.zip from the computer hosting WebLogic Server to the client computer, where WL_HOME refers to the WebLogic Server installation directory, such as /bea/wlserver_10.3.

  2. Unzip the wseeclient.zip file into the appropriate directory. For example, you might unzip the file into a directory that contains other classes used by your client application.

  3. Add the wseeclient.jar file (unzipped from the wseeclient.zip file) to your CLASSPATH.

    Also be sure that your CLASSPATH includes the JAR file that contains the Ant classes (ant.jar). This JAR file is typically located in the lib directory of the Ant distribution.

  4. If you are using JDK 6 Update 2, note that this version of the Sun JDK only supports JAX-WS 2.0 and JAXB 2.0 APIs. In order to use JDK 6 Update 2 with this release, you need to update the API JARs in your JDK6 installation. To do so:

    1. Copy the following JARs from the WebLogic Server installation into your Sun JDK6 endorsed directory:

      • $BEA_HOME/modules/javax.xml.bind_2.1.1 jar to JDK6_HOME/jre/lib/endorsed

      • $BEA_HOME/modules/javax.xml.ws_2.1.1 jar to JDK6_HOME/jre/lib/endorsed

    2. Use the Java endorsed library to override the existing JDK 6 Update 2 library files, as described in Java Endorsed Standards Override Mechanism.

 

Client Considerations When Redeploying a Web Service

WebLogic Server supports production redeployment, which means that you can deploy a new version of an updated WebLogic Web Service alongside an older version of the same Web Service.

WebLogic Server automatically manages client connections so that only new client requests are directed to the new version. Clients already connected to the Web Service during the redeployment continue to use the older version of the service until they complete their work, at which point WebLogic Server automatically retires the older Web Service.

You can continue using the old client application with the new version of the Web Service, as long as the following Web Service artifacts have not changed in the new version:

If any of these artifacts have changed, regenerate the JAX-WS stubs used by the client application by re-running the clientgen Ant task.

For example, if you change the signature of an operation in the new version of the Web Service, then the WSDL file that describes the new version of the Web Service will also change. In this case, regenerate the JAX-WS stubs. If, however, you simply change the implementation of an operation, but do not change its public contract, then you can continue using the existing client application.