Annotating the Code

JAX-WS relies on the annotation feature of Java 5. The JAX-WS annotations are used to specify the metadata used to map the SEI to a fully specified service definition. Among the information provided in the annotations are the following:

The target namespace for the service.
The name of the class used to hold the request message.
The name of the class used to hold the response message.
If an operation is a one way operation.
The binding style the service uses.
The name of the class used for any custom exceptions.
The namespaces under which the types used by the service are defined.

	Tip
	Most of the annotations have sensible defaults and do not need to be specified. However, the more information you provide in the annotations, the better defined your service definition. A solid service definition increases the likely hood that all parts of a distributed application will work together.

Required Annotations

In order to create a service from Java code you are only required to add one annotation to your code. You must add the @WebService() annotation on both the SEI and the implementation class.

The `@WebService` annotation

The @WebService annotation is defined by the javax.jws.WebService interface and it is placed on an interface or a class that is intended to be used as a service. @WebService has the following properties:

Table 1.1. @WebService Properties

Property	Description
name	Specifies the name of the service interface. This property is mapped to the `name` attribute of the `wsdl:portType` element that defines the service's interface in a WSDL contract. The default is to append `PortType` to the name of the implementation class. ^[a]
targetNamespace	Specifies the target namespace under which the service is defined. If this property is not specified, the target namespace is derived from the package name.
serviceName	Specifies the name of the published service. This property is mapped to the `name` attribute of the `wsdl:service` element that defines the published service. The default is to use the name of the service's implementation class. ^[a]
wsdlLocation	Specifies the URI at which the service's WSDL contract is stored. The default is the URI at which the service is deployed.
endpointInterface	Specifies the full name of the SEI that the implementation class implements. This property is only used when the attribute is used on a service implementation class.
portName	Specifies the name of the endpoint at which the service is published. This property is mapped to the `name` attribute of the `wsdl:port` element that specifies the endpoint details for a published service. The default is the append `Port` to the name of the service's implementation class. ^[a]
^[a]When you generate WSDL from an SEI the interface's name is used in place of the implementation class' name.

	Tip
	You do not need to provide values for any of the `@WebService` annotation's properties. However, it is recommended that you provide as much information as you can.

Annotating the SEI

The SEI requires that you add the @WebService annotation. Since the SEI is the contract that defines the service, you should specify as much detail as you can about the service in the @WebService annotation's properties.

Example 1.3, “Interface with the @WebService Annotation” shows the interface defined in Example 1.1, “Simple SEI” with the @WebService annotation.

Example 1.3. Interface with the @WebService Annotation

package com.iona.demo;

import javax.jws.*;

@WebService(name="quoteUpdater", 
            targetNamespace="http:\\demos.iona.com", 
	    serviceName="updateQuoteService", 
            wsdlLocation="http:\\demos.iona.com\quoteExampleService?wsdl", 
            portName="updateQuotePort") 
public interface quoteReporter
{
  public Quote getQuote(String ticker);
}

The @WebService annotation in Example 1.3, “Interface with the @WebService Annotation” does the following:

	Specifies that the value of the `name` attribute of the `wsdl:portType` element defining the service interface is `quoteUpdater`.
	Specifies that the target namespace of the service is `http:\\demos.iona.com`.
	Specifies that the value of the `name` of the `wsdl:service` element defining the published service is `updateQuoteService`.
	Specifies that the service will publish its WSDL contract at `http:\\demos.iona.com\quoteExampleService?wsdl`.
	Specifies that the value of the `name` attribute of the `wsdl:port` element defining the endpoint exposing the service is `updateQuotePort`.

Annotating the service implementation

In addition to annotating the SEI with the @WebService annotation, you also have to annotate the service implementation class with the @WebService annotation. When adding the annotation to the service implementation class you only need to specify the endpointInterface property. As shown in Example 1.4, “Annotated Service Implementation Class” the property needs to be set to the full name of the SEI.

Example 1.4. Annotated Service Implementation Class

package org.eric.demo;

import javax.jws.*;

@WebService(endpointInterface="com.iona.demo.quoteReporter")
public class stockQuoteReporter implements quoteReporter
{
public Quote getQuote(String ticker)
  {
  ...
  }
}

Optional Annotations

While the @WebService annotation is sufficient for service enabling a Java interface or a Java class, it does not provide a lot of information about how the service will be exposed as an endpoint. The JAX-WS programming model uses a number of optional annotations for adding details about your service, such as the binding it uses, to the Java code. You add these annotations to the service's SEI.

	Tip
	The more details you provide in the SEI the easier it will be for developers to implement applications that can use the functionality it defines. It will also provide for better generated WSDL contracts.

Defining the Binding Properties with Annotations

If you are using a SOAP binding for your service, you can use JAX-WS annotations to specify a number of the bindings properties. These properties correspond directly to the properties you can specify in a service's WSDL contract.

The `@SOAPBinding` annotation

The @SOAPBinding annotation is defined by the javax.jws.soap.SOAPBinding interface. It provides details about the SOAP binding used by the service when it is deployed. If the @SOAPBinding annotation is not specified, a service is published using a wrapped doc/literal SOAP binding.

You can put the @SOAPBinding annotation on the SEI and any of the SEI's methods. When it is used on a method, setting of the method's @SOAPBinding annotation take precedent.

Table 1.2, “@SOAPBinding Properties” shows the properties for the @SOAPBinding annotation.

Table 1.2. @SOAPBinding Properties

Property	Values	Description
style	`Style.DOCUMENT` (default) `Style.RPC`	Specifies the style of the SOAP message. If `RPC` style is specified, each message part within the SOAP body is a parameter or return value and will appear inside a wrapper element within the `soap:body` element. The message parts within the wrapper element correspond to operation parameters and must appear in the same order as the parameters in the operation. If `DOCUMENT` style is specified, the contents of the SOAP body must be a valid XML document, but its form is not as tightly constrained.
use	`Use.LITERAL` (default) `Use.ENCODED`	Specifies how the data of the SOAP message is streamed.
parameterStyle ^[a]	`ParameterStyle.BARE` `ParameterStyle.WRAPPED` (default)	Specifies how the method parameters, which correspond to message parts in a WSDL contract, are placed into the SOAP message body. A parameter style of `BARE` means that each parameter is placed into the message body as a child element of the message root. A parameter style of `WRAPPED` means that all of the input parameters are wrapped into a single element on a request message and that all of the output parameters are wrapped into a single element in the response message.
^[a]If you set the style to `RPC` you must use the `WRAPPED` parameter style.

Example 1.5, “Specifying an RPC/LITERAL SOAP Binding with the @SOAPBinding Annotation” shows an SEI that uses rpc/literal SOAP messages.

Example 1.5. Specifying an RPC/LITERAL SOAP Binding with the @SOAPBinding Annotation

package org.eric.demo;

import javax.jws.*;
import javax.jws.soap.*;
import javax.jws.soap.SOAPBinding.*;

@WebService(name="quoteReporter")
@SOAPBinding(style=Style.RPC, use=Use.LITERAL)
public interface quoteReporter
{
  ...
}

Defining Operation Properties with Annotations

When the runtime maps your Java method definitions into XML operation definitions it fills in details such as:

what the exchanged messages look like in XML.
if the message can be optimized as a one way message.
the namespaces where the messages are defined.

The `@WebMethod` annotation

The @WebMethod annotation is defined by the javax.jws.WebMethod interface. It is placed on the methods in the SEI. The @WebMethod annotation provides the information that is normally represented in the wsdl:operation element describing the operation to which the method is associated.

Table 1.3, “@WebMethod Properties” describes the properties of the @WebMethod annotation.

Table 1.3. @WebMethod Properties

Property	Description
operationName	Specifies the value of the associated `wsdl:operation` element's `name`. The default value is the name of the method.
action	Specifies the value of the `soapAction` attribute of the `soap:operation` element generated for the method. The default value is an empty string.
exclude	Specifies if the method should be excluded from the service interface. The default is `false`.

The `@RequestWrapper` annotation

The @RequestWrapper annotation is defined by the javax.xml.ws.RequestWrapper interface. It is placed on the methods in the SEI. As the name implies, @RequestWrapper specifies the Java class that implements the wrapper bean for the method parameters that are included in the request message sent in a remote invocation. It is also used to specify the element names, and namespaces, used by the runtime when marshalling and unmarshalling the request messages.

Table 1.4, “@RequestWrapper Properties” describes the properties of the @RequestWrapper annotation.

Table 1.4. @RequestWrapper Properties

Property	Description
localName	Specifies the local name of the wrapper element in the XML representation of the request message. The default value is the name of the method or the value of the `@WebMethod` annotation's operationName property.
targetNamespace	Specifies the namespace under which the XML wrapper element is defined. The default value is the target namespace of the SEI.
className	Specifies the full name of the Java class that implements the wrapper element.

	Tip
	Only the className property is required.

The `@ResponseWrapper` annotation

The @ResponseWrapper annotation is defined by the javax.xml.ws.ResponseWrapper interface. It is placed on the methods in the SEI. As the name implies, @ResponseWrapper specifies the Java class that implements the wrapper bean for the method parameters that are included in the response message sent in a remote invocation. It is also used to specify the element names, and namespaces, used by the runtime when marshalling and unmarshalling the response messages.

Table 1.5, “@ResponseWrapper Properties” describes the properties of the @ResponseWrapper annotation.

Table 1.5. @ResponseWrapper Properties

Property	Description
localName	Specifies the local name of the wrapper element in the XML representation of the response message. The default value is the name of the method with `Response` appended or the value of the `@WebMethod` annotation's operationName property with `Response` appended.
targetNamespace	Specifies the namespace under which the XML wrapper element is defined. The default value is the target namespace of the SEI.
className	Specifies the full name of the Java class that implements the wrapper element.

	Tip
	Only the className property is required.

The `@WebFault` annotation

The @WebFault annotation is defined by the javax.xml.ws.WebFault interface. It is placed on methods in the SEI that throw exceptions. The @WebFault annotation is used to map the Java exception to a wsdl:fault element. This information is used to marshall the exceptions into a representation that can be processed by both the service and its consumers.

Table 1.6, “@WebFault Properties” describes the properties of the @WebFault annotation.

Table 1.6. @WebFault Properties

Property	Description
name	Specifies the local name of the fault element.
targetNamespace	Specifies the namespace under which the fault element is defined. The default value is the target namespace of the SEI.
faultName	Specifies the full name of the Java class that implements the exception.

	Important
	The name property is required.

The `@OneWay` annotation

The @OneWay annotation is defined by the javax.jws.OneWay interface. It is placed on the methods in the SEI that will not require a response from the service. The @OneWay annotation tells the run time that it can optimize the execution of the method by not waiting for a response and not reserving any resources to process a response.

Example

Example 1.6, “SEI with Annotated Methods” shows an SEI whose methods are annotated.

Example 1.6. SEI with Annotated Methods

package com.iona.demo;

import javax.jws.*;
import javax.xml.ws.*;

@WebService(name="quoteReporter")
public interface quoteReporter
{
  @WebMethod(operationName="getStockQuote")
  @RequestWrapper(targetNamespace="http://demo.iona.com/types", 
                  className="java.lang.String")
  @ResponseWrapper(targetNamespace="http://demo.iona.com/types", 
                   className="org.eric.demo.Quote")
  public Quote getQuote(String ticker);
}

Defining Parameter Properties with Annotations

The method parameters in the SEI coresspond to the wsdl:message elements and their wsdl:part elements. JAX-WS provides annotations that allow you to describe the wsdl:part elements that are generated for the method parameters.

The `@WebParam` annotation

The @WebParam annotation is defined by the javax.jws.WebParam interface. It is placed on the parameters on the methods defined in the SEI. The @WebParam annotation allows you to specify the direction of the parameter, if the parameter will be placed in the SOAP header, and other properties of the generated wsdl:part.

Table 1.7, “@WebParam Properties” describes the properties of the @WebParam annotation.

Table 1.7. @WebParam Properties

Property	Values	Description
name		Specifies the name of the parameter as it appears in the WSDL. For RPC bindings, this is name of the `wsdl:part` representing the parameter. For document bindings, this is the local name of the XML element representing the parameter. The default is to use the name of the parameter as it appears in the method's argument list.
targetNamespace		Specifies the namespace for the parameter. It is only used with document bindings where the parameter maps to an XML element. The defaults is to use the service's namespace.
mode	`Mode.IN` (default) `Mode.OUT` `Mode.INOUT`	Specifies the direction of the parameter.
header	`false` (default) `true`	Specifies if the parameter is passed as part of the SOAP header.
partName		Specifies the value of the `name` attribute of the `wsdl:part` element for the parameter when the binding is document.

The `@WebResult` annotation

The @WebResult annotation is defined by the javax.jws.WebResult interface. It is placed on the methods defined in the SEI. The @WebResult annotation allows you to specify the properties of the generated wsdl:part that is generated for the method's return value.

Table 1.8, “@WebResult Properties” describes the properties of the @WebResult annotation.

Table 1.8. @WebResult Properties

Property	Description
name	Specifies the name of the return value as it appears in the WSDL. For RPC bindings, this is name of the `wsdl:part` representing the return value. For document bindings, this is the local name of the XML element representing the return value. The default value is `return`.
targetNamespace	Specifies the namespace for the return value. It is only used with document bindings where the return value maps to an XML element. The defaults is to use the service's namespace.
header	Specifies if the return value is passed as part of the SOAP header.
partName	Specifies the value of the `name` attribute of the `wsdl:part` element for the return value when the binding is document.

Example

Example 1.7, “Fully Annotated SEI” shows an SEI that is fully annotated.

Example 1.7. Fully Annotated SEI

package com.iona.demo;

import javax.jws.*;
import javax.xml.ws.*;
import javax.jws.soap.*;
import javax.jws.soap.SOAPBinding.*;
import javax.jws.WebParam.*;

@WebService(targetNamespace="http://demo.iona.com", 
            name="quoteReporter")
@SOAPBinding(style=Style.RPC, use=Use.LITERAL)
public interface quoteReporter
{
  @WebMethod(operationName="getStockQuote")
  @RequestWrapper(targetNamespace="http://demo.iona.com/types", 
                  className="java.lang.String")
  @ResponseWrapper(targetNamespace="http://demo.iona.com/types", 
                   className="org.eric.demo.Quote")
  @WebResult(targetNamespace="http://demo.iona.com/types", 
             name="updatedQuote")
  public Quote getQuote(
                        @WebParam(targetNamespace="http://demo.iona.com/types", 
                                  name="stockTicker",
                                  mode=Mode.IN)
                        String ticker
  );
}