Getting Started With WebLogic Web Services Using JAX-WS

Programming the JWS File

The following sections provide information about programming the JWS file that implements your Web Service:

Overview of JWS Files and JWS Annotations

There are two ways to program a WebLogic Web Service from scratch:

Oracle strongly recommends using option 1 above. Instead of authoring XML metadata descriptors yourself, the WebLogic Ant tasks and runtime will generate the required descriptors and artifacts based on the annotations you include in your JWS. Not only is this process much easier, but it keeps the information about your Web Service in a central location, the JWS file, rather than scattering it across many Java and XML files.

The Java Web Service (JWS) annotated file is the core of your Web Service. It contains the Java code that determines how your Web Service behaves. A JWS file is an ordinary Java class file that uses Java metadata annotations to specify the shape and characteristics of the Web Service. The JWS annotations you can use in a JWS file include the standard ones defined by the Web Services Metadata for the Java Platform specification (JSR-181) plus a set of additional annotations based on the type of Web Service you are building—JAX-WS or JAX-RPC. For a complete list of JWS annotations that are supported for JAX-WS and JAX-RPC Web Services, see “Web Service Annotation Support” in WebLogic Web Services Reference.

When programming the JWS file, you include annotations to program basic Web Service features. The annotations are used at different levels, or targets, in your JWS file. Some are used at the class-level to indicate that the annotation applies to the entire JWS file. Others are used at the method-level and yet others at the parameter level.

Java Requirements for a JWS File

When you program your JWS file, you must follow a set of requirements, as specified by the Web Services Metadata for the Java Platform specification (JSR-181). In particular, the Java class that implements the Web Service:

Programming the JWS File: Typical Steps

The following procedure describes the typical steps for programming a JWS file that implements a Web Service.

For more information about each of the JWS annotations, see “JWS Annotation Reference” in WebLogic Web Services Reference.

Example of a JWS File

The following sample JWS file shows how to implement a simple Web Service.

package examples.webservices.simple;

// Import the standard JWS annotation interfaces

import javax.jws.WebMethod;
import javax.jws.WebService;
import javax.jws.soap.SOAPBinding;

// Standard JWS annotation that specifies that the porType name of the Web
// Service is "SimplePortType", the service name is "SimpleService", and the
// targetNamespace used in the generated WSDL is "http://example.org"

@WebService(name="SimplePortType", serviceName="SimpleService",
            targetNamespace="http://example.org")

// Standard JWS annotation that specifies the mapping of the service onto the
// SOAP message protocol.  In particular, it specifies that the SOAP messages
// are document-literal-wrapped.

@SOAPBinding(style=SOAPBinding.Style.DOCUMENT,
             use=SOAPBinding.Use.LITERAL,
             parameterStyle=SOAPBinding.ParameterStyle.WRAPPED)

/**
 * This JWS file forms the basis of simple Java-class implemented WebLogic
 * Web Service with a single operation: sayHello
 *
 */

public class SimpleImpl {

  // Standard JWS annotation that specifies that the method should be exposed
  // as a public operation.  Because the annotation does not include the
  // member-value "operationName", the public name of the operation is the
 // same as the method name: sayHello.

  @WebMethod()
  public String sayHello(String message) {
    System.out.println("sayHello:" + message);
    return "Here is the message: '" + message + "'";
  }
}

Specifying that the JWS File Implements a Web Service (@WebService Annotation)

Use the standard @WebService annotation to specify, at the class level, that the JWS file implements a Web Service, as shown in the following code excerpt:

@WebService(name="SimplePortType", serviceName="SimpleService",
            targetNamespace="http://example.org")

In the example, the name of the Web Service is SimplePortType, which will later map to the wsdl:portType element in the WSDL file generated by the jwsc Ant task. The service name is SimpleService, which will map to the wsdl:service element in the generated WSDL file. The target namespace used in the generated WSDL is http://example.org.

You can also specify the following additional attributes of the @WebService annotation:

None of the attributes of the @WebService annotation is required. See the Web Services Metadata for the Java Platform (JSR 181) for the default values of each attribute.

Specifying the Mapping of the Web Service to the SOAP Message Protocol (@SOAPBinding Annotation)

It is assumed that you want your Web Service to be available over the SOAP message protocol; for this reason, your JWS file should include the standard @SOAPBinding annotation, at the class level, to specify the SOAP bindings of the Web Service (such as, document-encoded or document-literal-wrapped), as shown in the following code excerpt:

@SOAPBinding(style=SOAPBinding.Style.DOCUMENT,
             use=SOAPBinding.Use.LITERAL,
             parameterStyle=SOAPBinding.ParameterStyle.WRAPPED)

In the example, the Web Service uses document-wrapped-style encodings and literal message formats, which are also the default formats if you do not specify the @SOAPBinding annotation.

You use the parameterStyle attribute (in conjunction with the style=SOAPBinding.Style.DOCUMENT attribute) to specify whether the Web Service operation parameters represent the entire SOAP message body, or whether the parameters are elements wrapped inside a top-level element with the same name as the operation.

The following table lists the possible and default values for the three attributes of the @SOAPBinding (either the standard or WebLogic-specific) annotation.

Specifying That a JWS Method Be Exposed as a Public Operation (@WebMethod and @OneWay Annotations)

Use the standard @WebMethod annotation to specify that a method of the JWS file should be exposed as a public operation of the Web Service, as shown in the following code excerpt:

public class SimpleImpl {

  @WebMethod(operationName="sayHelloOperation")
  public String sayHello(String message) {
    System.out.println("sayHello:" + message);
    return "Here is the message: '" + message + "'";
  }
...

In the example, the sayHello() method of the SimpleImpl JWS file is exposed as a public operation of the Web Service. The operationName attribute specifies, however, that the public name of the operation in the WSDL file is sayHelloOperation. If you do not specify the operationName attribute, the public name of the operation is the name of the method itself.

You can also use the action attribute to specify the action of the operation. When using SOAP as a binding, the value of the action attribute determines the value of the SOAPAction header in the SOAP messages.

You can specify that an operation not return a value to the calling application by using the standard @Oneway annotation, as shown in the following example:

 public class OneWayImpl {

  @WebMethod()
  @Oneway()

  public void ping() {
    System.out.println("ping operation");
  }

...

If you specify that an operation is one-way, the implementing method is required to return void, cannot use a Holder class as a parameter, and cannot throw any checked exceptions.

None of the attributes of the @WebMethod annotation is required. See the Web Services Metadata for the Java Platform (JSR 181) for the default values of each attribute, as well as additional information about the @WebMethod and @Oneway annotations.

If none of the public methods in your JWS file are annotated with the @WebMethod annotation, then by default all public methods are exposed as Web Service operations.

Customizing the Mapping Between Operation Parameters and WSDL Elements (@WebParam Annotation)

Use the standard @WebParam annotation to customize the mapping between operation input parameters of the Web Service and elements of the generated WSDL file, as well as specify the behavior of the parameter, as shown in the following code excerpt:

 public class SimpleImpl {

  @WebMethod()
  @WebResult(name="IntegerOutput",
             targetNamespace="http://example.org/docLiteralBare")
  public int echoInt(
      @WebParam(name="IntegerInput",
                targetNamespace="http://example.org/docLiteralBare")
      int input)

  {
      System.out.println("echoInt '" + input + "' to you too!");
      return input;
  }
...

In the example, the name of the parameter of the echoInt operation in the generated WSDL is IntegerInput; if the @WebParam annotation were not present in the JWS file, the name of the parameter in the generated WSDL file would be the same as the name of the method’s parameter: input. The targetNamespace attribute specifies that the XML namespace for the parameter is http://example.org/docLiteralBare; this attribute is relevant only when using document-style SOAP bindings where the parameter maps to an XML element.

You can also specify the following additional attributes of the @WebParam annotation:

None of the attributes of the @WebParam annotation is required. See the Web Services Metadata for the Java Platform (JSR 181) for the default value of each attribute.

Customizing the Mapping Between the Operation Return Value and a WSDL Element (@WebResult Annotation)

Use the standard @WebResult annotation to customize the mapping between the Web Service operation return value and the corresponding element of the generated WSDL file, as shown in the following code excerpt:

 public class Simple {

  @WebMethod()
  @WebResult(name="IntegerOutput",
             targetNamespace="http://example.org/docLiteralBare")
  public int echoInt(
      @WebParam(name="IntegerInput",
                targetNamespace="http://example.org/docLiteralBare")
      int input)

  {
      System.out.println("echoInt '" + input + "' to you too!");
      return input;
  }
...

In the example, the name of the return value of the echoInt operation in the generated WSDL is IntegerOutput; if the @WebResult annotation were not present in the JWS file, the name of the return value in the generated WSDL file would be the hard-coded name return. The targetNamespace attribute specifies that the XML namespace for the return value is http://example.org/docLiteralBare; this attribute is relevant only when using document-style SOAP bindings where the return value maps to an XML element.

None of the attributes of the @WebResult annotation is required. See the Web Services Metadata for the Java Platform (JSR 181) for the default value of each attribute.

Specifying the Binding to Use for an Endpoint (@BindingType Annotation)

Use the JAX-WS @BindingType annotation to customize the binding to use for a web service endpoint implementation class, as shown in the following code excerpt:

import javax.xml.ws.BindingType;
import javax.xml.ws.soap.SOAPBinding;
 public class Simple {

  @WebService()
  @BindingType(value=SOAPBinding.SOAP12HTTP_BINDING)
  public int echoInt(
      @WebParam(name="IntegerInput",
                targetNamespace="http://example.org/docLiteralBare")
      int input)

  {
      System.out.println("echoInt '" + input + "' to you too!");
      return input;
  }
...

In the example, the deployed endpoint would use the SOAP1.2 over HTTP binding. If not specified, the binding defaults to SOAP 1.1 over HTTP.

You can also specify the following additional attributes of the @BindingType annotation:

For more information about the @BindingType annotation, see JAX-WS 2.1 Annotations.

Accessing Runtime Information About a Web Service

When a client application invokes a WebLogic Web Service that was implemented with a JWS file, WebLogic Server automatically creates a context that the Web Service or client can use to access, and sometimes change, runtime information about the service.

To access runtime information, you can use one of the following methods:

The following sections describe how to use the BindingProvider, WebServiceContext, and MessageContext to access runtime information in more detail.

Accessing the Protocol Binding Context

The javax.xml.ws.BindingProvider interface enables you to access from the client application the request and response context of the protocol binding. For more information about developing Web Service client files, see Invoking Web Services.

The following example shows a simple Web Service client application that uses the context to access HTTP request header information. The code in bold is discussed in the programming guidelines described following the example.

package examples.webservices.hello_world.client;

import javax.xml.namespace.QName;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Map;
import javax.xml.ws.BindingProvider;
import javax.xml.ws.handler.MessageContext;
import com.sun.xml.ws.developer.JAXWSProperties;
import com.sun.xml.ws.client.BindingProviderProperties;

/**
 * This is a simple standalone client application that invokes the
 * the <code>sayHelloWorld</code> operation of the Simple Web service.
 */

public class Main {
  public static void main(String[] args) {
    HelloWorldService service;
    try { 
       service = new HelloWorldService(new URL(args[0] + "?WSDL"), 
           new QName("http://hello_world.webservices.examples/", 
           "HelloWorldService") );
    } catch (MalformedURLException murl) { throw new RuntimeException(murl); }
      HelloWorldPortType port = service.getHelloWorldPortTypePort();
      String result = null;
      result = port.sayHelloWorld("Hi there!");
      System.out.println( "Got result: " + result );
      Map requestContext = ((BindingProvider)port).getRequestContext();
      requestContext.put(BindingProvider.ENDPOINT_ADDRESS_PROPERTY,
                       "http://examples.com/HelloWorldImpl/HelloWorldService");
      requestContext.put(JAXWSProperties.CONNECT_TIMEOUT, 300); 
      requestContext.put(BindingProviderProperties.REQUEST_TIMEOUT, 300); 
      Map responseContext = ((BindingProvider)port).getResponseContext();
      Integer responseCode = 
               (Integer)responseContext.get(MessageContext.HTTP_RESPONSE_CODE);
...
  }
}

Use the following guidelines in your JWS file to access the runtime context of the Web Service, as shown in the code in bold in the preceding example:

The following table summarizes the methods of the javax.xml.ws.BindingProvider that you can use in your JWS file to access runtime information about the Web Service.

One you get the request or response context, you can access the BindingProvider property values defined in the following table and the MessageContext property values defined in Using the MessageContext Property Values.

In addition, in the previous example:

Accessing the Web Service Context

The javax.xml.ws.WebServiceContext interface enables you to access from the Web Service runtime message context and security information relative to a request being served. Typically, a WebServiceContext is injected into an endpoint using the @Resource annotation.

The following example shows a simple JWS file that uses the context to access HTTP request header information. The code in bold is discussed in the programming guidelines described following the example.

package examples.webservices.jws_context;

import javax.jws.WebMethod;
import javax.jws.WebService;

import java.util.Map;
import javax.xml.ws.WebServiceContext;
import javax.annotation.Resource;
import javax.xml.ws.handler.MessageContext;

@WebService(name="JwsContextPortType", serviceName="JwsContextService",
            targetNamespace="http://example.org")

/**
 * Simple web service to show how to use the @Context annotation.
 */

public class JwsContextImpl {

  @Resource
  private WebServiceContext ctx; 

  @WebMethod()
  public String msgContext(String msg) {
    MessageContext context=ctx.getMessageContext();
    Map requestHeaders = (Map)context.get(MessageContext.HTTP_REQUEST_HEADERS);
  }

}

Use the following guidelines in your JWS file to access the runtime context of the Web Service, as shown in the code in bold in the preceding example:

The following table summarizes the methods of the javax.xml.ws.WebServiceContext that you can use in your JWS file to access runtime information about the Web Service.

Using the MessageContext Property Values

The following table defined the javax.xml.ws.handler.MessageContext property values that you can access from a message handler—from the client application or Web Service—or directly from the WebServiceContext from the Web Service. For more information, see the javax.xml.ws.handler.MessageContext Javadocs.

Should You Implement a Stateless Session EJB?

The jwsc Ant task always chooses a plain Java object as the underlying implementation of a Web Service when processing your JWS file.

Sometimes, however, you might want the underlying implementation of your Web Service to be a stateless session EJB so as to take advantage of all that EJBs have to offer, such as instance pooling, transactions, security, container-managed persistence, container-managed relationships, and data caching. If you decide you want an EJB implementation for your Web Service, then follow the programming guidelines in the following section.

EJB 3.0 introduced metadata annotations that enable you to automatically generate, rather than manually create, the EJB Remote and Home interface classes and deployment descriptor files needed when implementing an EJB. For more information about EJB 3.0, see Enterprise JavaBeans (EJB) 3.0.

To implement an EJB in your JWS file, perform the following steps:

The following example shows a simple JWS file that implement a stateless session EJB. The relevant code is shown in bold.

package examples.webservices.jaxws;

import weblogic.transaction.TransactionHelper;
import javax.ejb.Stateless;
import javax.ejb.SessionContext;
import javax.ejb.TransactionAttribute;
import javax.ejb.TransactionAttributeType;
import javax.annotation.Resource;
import javax.jws.WebService;
import javax.jws.WebMethod;
import javax.transaction.SystemException;
import javax.transaction.Status;
import javax.transaction.Transaction;
import javax.xml.ws.WebServiceContext;

/**
* A transaction-awared stateless EJB-implemented JWS
*/

// Standard JWS annotation that specifies that the portName,serviceName and
// target Namespace of the Web Service.
@WebService(
	name = "Simple",
	portName = "SimpleEJBPort",
	serviceName = "SimpleEjbService",
	targetNamespace = "http://www.bea.com/wls/samples")

//Standard EJB annotation
@Stateless
public class SimpleEjbImpl {

   @Resource
   private WebServiceContext context;
   private String constructed = null;

   // The WebMethod annotation exposes the subsequent method as a public
   // operation on the Web Service.
   @WebMethod()
   @TransactionAttribute(TransactionAttributeType.REQUIRED)
   public String sayHello(String s) throws SystemException {
      Transaction transaction =     
         TransactionHelper.getTransactionHelper().getTransaction();
      int status = transaction.getStatus();
      if (Status.STATUS_ACTIVE != status)
           throw new IllegalStateException("transaction did not start, 
           status is: " + status + ", check ejb annotation processing");

   return constructed + ":" + s;
}

Programming the User-Defined Java Data Type

The methods of the JWS file that are exposed as Web Service operations do not necessarily take built-in data types (such as Strings and integers) as parameters and return values, but rather, might use a Java data type that you create yourself. An example of a user-defined data type is TradeResult, which has two fields: a String stock symbol and an integer number of shares traded.

If your JWS file uses user-defined data types as parameters or return values of one or more of its methods, you must create the Java code of the data type yourself, and then import the class into your JWS file and use it appropriately. The jwsc Ant task will later take care of creating all the necessary data binding artifacts.

Follow these basic requirements when writing the Java class for your user-defined data type:

The jwsc Ant task can generate data binding artifacts for most common XML and Java data types. For the list of supported user-defined data types, see Supported User-Defined Data Types. See Supported Built-In Data Types for the full list of supported built-in data types.

The following example shows a simple Java user-defined data type called BasicStruct:

package examples.webservices.complex;

/**
 * Defines a simple JavaBean called BasicStruct that has integer, String,
 * and String[] properties
 */

public class BasicStruct {

  // Properties

  private int intValue;
  private String stringValue;
  private String[] stringArray;

  // Getter and setter methods

  public int getIntValue() {
    return intValue;
  }

  public void setIntValue(int intValue) {
    this.intValue = intValue;
  }

  public String getStringValue() {
    return stringValue;
  }

  public void setStringValue(String stringValue) {
    this.stringValue = stringValue;
  }

  public String[] getStringArray() {
    return stringArray;
  }

  public void setStringArray(String[] stringArray) {
    this.stringArray = stringArray;
  }

}

The following snippets from a JWS file show how to import the BasicStruct class and use it as both a parameter and return value for one of its methods; for the full JWS file, see Sample ComplexImpl.java JWS File:

package examples.webservices.complex;

// Import the standard JWS annotation interfaces

import javax.jws.WebMethod;
import javax.jws.WebParam;
import javax.jws.WebResult;
import javax.jws.WebService;
import javax.jws.soap.SOAPBinding;

// Import the WebLogic-specific JWS annotation interface

// Import the BasicStruct JavaBean

import examples.webservices.complex.BasicStruct;

@WebService(serviceName="ComplexService", name="ComplexPortType",
            targetNamespace="http://example.org")

...

public class ComplexImpl {

  @WebMethod(operationName="echoComplexType")
  public BasicStruct echoStruct(BasicStruct struct)

  {
    return struct;
  }
}

Invoking Another Web Service from the JWS File

From within your JWS file you can invoke another Web Service, either one deployed on WebLogic Server or one deployed on some other application server, such as .NET. The steps to do this are similar to those described in Invoking a Web Service from a Stand-alone Java Client, except that rather than running the clientgen Ant task to generate the client stubs, you include a <clientgen> child element of the jwsc Ant task that builds the invoking Web Service to generate the client stubs instead. You then use the standard JAX-WS APIs in your JWS file the same as you do in a stand-alone client application.

See Invoking a Web Service from Another Web Service for detailed instructions.

Using SOAP 1.2

WebLogic Web Services use, by default, Version 1.1 of Simple Object Access Protocol (SOAP) as the message format when transmitting data and invocation calls between the Web Service and its client. WebLogic Web Services support both SOAP 1.1 and the newer SOAP 1.2, and you are free to use either version.

To specify that the Web Service use Version 1.2 of SOAP, use the class-level @javax.xml.ws.BindingType annotation in your JWS file and set its single attribute to the value SOAPBinding.SOAP12HTTP_BINDING, as shown in the following example (relevant code shown in bold):

package examples.webservices.soap12;

import javax.jws.WebMethod;
import javax.jws.WebService;

import javax.xml.ws.BindingType;
import javax.xml.ws.SOAPBinding;

@WebService(name="SOAP12PortType",
            serviceName="SOAP12Service",
            targetNamespace="http://example.org")

@BindingType(value = SOAPBinding.SOAP12HTTP_BINDING)
/**
 * This JWS file forms the basis of simple Java-class implemented WebLogic
 * Web Service with a single operation: sayHello.  The class uses SOAP 1.2
 * as its binding.
 *
 */

public class SOAP12Impl {

  @WebMethod()
  public String sayHello(String message) {
    System.out.println("sayHello:" + message);
    return "Here is the message: '" + message + "'";
  }
}

Other than set this annotation, you do not have to do anything else for the Web Service to use SOAP 1.2, including changing client applications that invoke the Web Service; the WebLogic Web Services runtime takes care of all the rest.

Validating the XML Schema

By default, SOAP messages are not validated against their XML schemas. You can enable XML schema validation for document-literal Web Services on the server or client, as described in the following sections.

Enabling Schema Validation on the Server

To enable schema validation on the server, add the @SchemaValidation annotation on the endpoint implementation. For example:

import com.sun.xml.ws.developer.SchemaValidation;
import javax.jws.WebService;

@SchemaValidation
@WebService(name="HelloWorldPortType", serviceName="HelloWorldService")
public class HelloWorldImpl {
  public String sayHelloWorld(String message) {
    System.out.println("sayHelloWorld:" + message);
    return "Here is the message: '" + message + "'";
  }
}

You can pass your own validation error handler class as an argument to the annotation, if you want to manage errors within your application. For example:

@SchemaValidation(handler=ErrorHandler.class)

Enabling Schema Validation on the Client

To enable schema validation on the client, create a SchemaValidationFeature object and pass this as an argument when creating the PortType stub implementation.

package examples.webservices.hello_world.client;

import com.sun.xml.ws.developer.SchemaValidationFeature;
import javax.xml.namespace.QName;
import java.net.MalformedURLException;
import java.net.URL;
public class Main {

  public static void main(String[] args) {
    HelloWorldService service;
    try {
      service = new HelloWorldService(new URL(args[0] + "?WSDL"), 
                new QName("http://example.org", "HelloWorldService") );
    } catch (MalformedURLException murl) { throw new RuntimeException(murl); }
      SchemaValidationFeature feature = 
           new SchemaValidationFeature();
       HelloWorldPortType port = service.getHelloWorldPortTypePort(feature);
      String result = null;
      result = port.sayHelloWorld("Hi there!");
      System.out.println( "Got result: " + result );
  }
}

You can pass your own validation error handler as an argument to the SchemaValidationFeature object, if you want to manage errors within your application. For example:

      SchemaValidationFeature feature = 
           new SchemaValidationFeature(MyErrorHandler.class);
       HelloWorldPortType port = service.getHelloWorldPortTypePort(feature);

JWS Programming Best Practices

The following list provides some best practices when programming the JWS file: