Spring Web Services

Spring Web Services Component

Available as of Camel 2.6

The springws: component allows you to integrate with Spring Web Services It offers both client-side support, for accessing web services, and server-side support for creating your own contract-first web services.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
	<groupId>org.apache.camel</groupId>
	<artifactId>camel-spring-ws</artifactId>
	<version>x.x.x</version>
	<!-- use the same version as your Camel core version -->
</dependency>

Dependencies

This component offers support for Spring-WS 1.5.9 which is compatible with Spring 2.5.x. In order to run Spring-WS 1.5.9 on Spring 3.0 you need to exclude the OXM module from Spring 3.0 as this module is also included in Spring-WS 1.5.9 (see this post)

URI format

The URI scheme for this component is as follows

springws:[mapping-type:]address[?options]

To expose a web service mapping-type needs to be set to any of the following:

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Mapping type	Description
`rootqname`	Offers the option to map web service requests based on the qualified name of the root element contained in the message.
`soapaction`	Used to map web service requests based on the SOAP action specified in the header of the message.
`uri`	In order to map web service requests that target a specific URI.
`xpathresult`	Used to map web service requests based on the evaluation of an XPath `expression` against the incoming message. The result of the evaluation should match the XPath result specified in the endpoint URI.
`beanname`	Allows you to reference a `org.apache.camel.component.spring.ws.bean.CamelEndpointDispatcher` in order to integrate with existing (legacy) endpoint mappings like `PayloadRootQNameEndpointMapping`, `SoapActionEndpointMapping`, etc

As a consumer the address should contain a value relevant to the specified mapping-type (e.g. a SOAP action, XPath expression). As a provider the address should be set to the URI of the web service your calling upon.

You can append query options to the URI in the following format, ?option=value&option=value&...

Options

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Name	Required?	Description
`soapAction`	No	SOAP action to include inside a SOAP request when accessing remote web services
`wsAddressingAction`	No	WS-Addressing 1.0 action header to include when accessing web services. The `To` header is set to the address of the web service as specified in the endpoint URI (default Spring-WS behavior).
`expression`	Only when mapping-type is `xpathresult`	XPath expression to use in the process of mapping web service requests, should match the result specified by `xpathresult`

Registry based options

The following options can be specified in the registry (most likely a Spring ApplicationContext) and referenced from the endpoint URI using the # notation.

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Name	Required?	Description
`webServiceTemplate`	No	Option to provide a custom WebServiceTemplate. This allows for full control over client-side web services handling; like adding a custom interceptor or specifying a fault resolver, message sender or message factory.
`messageSender`	No	Option to provide a custom WebServiceMessageSender. For example to perform authentication or use alternative transports
`messageFactory`	No	Option to provide a custom WebServiceMessageFactory. For example when you want Apache Axiom to handle web service messages instead of SAAJ
`transformerFactory`	No	Option to override default TransformerFactory. The provided transformer factory must be of type `javax.xml.transform.TransformerFactory`
`endpointMapping`	Only when mapping-type is `rootqname`, `soapaction`, `uri` or `xpathresult`	Reference to `org.apache.camel.component.spring.ws.bean.CamelEndpointMapping` in the Registry/ApplicationContext. Only one bean is required in the registry to serve all Camel/Spring-WS endpoints. This bean is auto-discovered by the MessageDispatcher and used to map requests to Camel endpoints based on characteristics specified on the endpoint (like root QName, SOAP action, etc)

Message headers

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Name	Type	Description
`CamelSpringWebserviceEndpointUri`	String	URI of the web service your accessing as a client, overrides address part of the endpoint URI
`CamelSpringWebserviceSoapAction`	String	Header to specify the SOAP action of the message, overrides `soapAction` option if present
`CamelSpringWebserviceAddressingAction`	URI	Use this header to specify the WS-Addressing action of the message, overrides `wsAddressingAction` option if present

Accessing web services

To call a web service at http://foo.com/bar simply define a route:

from("direct:example").to("springws:http://foo.com/bar")

And sent a message:

template.requestBody("direct:example", "<foobar xmlns=\"http://foo.com\"><msg>test message</msg></foobar>");

Sending SOAP and WS-Addressing action headers

When a remote web service requires a SOAP action or use of the WS-Addressing standard you define your route as:

from("direct:example")
.to("springws:http://foo.com/bar?soapAction=http://foo.com&wsAddressingAction=http://bar.com")

Optionally you can override the endpoint options with header values:

template.requestBodyAndHeader("direct:example", 
"<foobar xmlns=\"http://foo.com\"><msg>test message</msg></foobar>", 
SpringWebserviceConstants.SPRING_WS_SOAP_ACTION, "http://baz.com");

Using a custom MessageSender and MessageFactory

A custom message sender or factory in the registry can be referenced like this:

from("direct:example")
.to("springws:http://foo.com/bar?messageFactory=#messageFactory&messageSender=#messageSender")

Spring configuration:

 
<!-- authenticate using HTTP Basic Authentication -->
<bean id="messageSender" class="org.springframework.ws.transport.http.CommonsHttpMessageSender">
	<property name="credentials">
		<bean class="org.apache.commons.httpclient.UsernamePasswordCredentials">
			<constructor-arg index="0" value="admin"/>
			<constructor-arg index="1" value="secret"/>
		</bean>
	</property>
</bean>

<!-- force use of Sun SAAJ implementation, http://static.springsource.org/spring-ws/sites/1.5/faq.html#saaj-jboss -->
<bean id="messageFactory" class="org.springframework.ws.soap.saaj.SaajSoapMessageFactory">
	<property name="messageFactory">
		<bean class="com.sun.xml.messaging.saaj.soap.ver1_1.SOAPMessageFactory1_1Impl"></bean>
	</property>
</bean>

Exposing web services

In order to expose a web service using this component you first need to set-up a MessageDispatcher to look for endpoint mappings in a Spring XML file. If you plan on running inside a servlet container you probably want to use a MessageDispatcherServlet configured in web.xml.

By default the MessageDispatcherServlet will look for a Spring XML named /WEB-INF/spring-ws-servlet.xml. To use Camel with Spring-WS the only mandatory bean in that XML file is CamelEndpointMapping. This bean allows the MessageDispatcher to dispatch web service requests to your routes.

web.xml

 
<web-app>
    <servlet>
        <servlet-name>spring-ws</servlet-name>
        <servlet-class>org.springframework.ws.transport.http.MessageDispatcherServlet</servlet-class>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>spring-ws</servlet-name>
        <url-pattern>/*</url-pattern>
    </servlet-mapping>
</web-app>

spring-ws-servlet.xml

 
<bean id="endpointMapping" class="org.apache.camel.component.spring.ws.bean.CamelEndpointMapping" />

<bean id="wsdl" class="org.springframework.ws.wsdl.wsdl11.DefaultWsdl11Definition">
	<property name="schema"> 
		<bean class="org.springframework.xml.xsd.SimpleXsdSchema">                   
			<property name="xsd" value="/WEB-INF/foobar.xsd"/>
		</bean>    
	</propert>                                        
	<property name="portTypeName" value="FooBar"/>                                
	<property name="locationUri" value="/"/>                              
	<property name="targetNamespace" value="http://example.com/"/>       
</bean>

More information on setting up Spring-WS can be found in Writing Contract-First Web Services. Basically paragraph 3.6.2 "Routing the Message to the Endpoint" is where CamelEndpointMapping comes in.

Endpoint mapping in routes

With the XML configuration in-place you can now use Camel's DSL to define what web service request are handled by your endpoint:

The following route will receive all web service requests that have a root element named "GetFoo" within the http://example.com/ namespace.

from("springws:rootqname:{http://example.com/}GetFoo?endpointMapping=#endpointMapping")
.convertBodyTo(String.class).to(mock:example)

The following route will receive web service requests containing the http://example.com/GetFoo SOAP action.

from("springws:soapaction:http://example.com/GetFoo?endpointMapping=#endpointMapping")
.convertBodyTo(String.class).to(mock:example)

The following route will receive all requests sent to http://example.com/foobar.

from("springws:uri:http://example.com/foobar?endpointMapping=#endpointMapping")
.convertBodyTo(String.class).to(mock:example)

The route below will receive requests that contain the element <foobar>abc</foobar> anywhere inside the message (and the default namespace).

from("springws:xpathresult:abc?expression=//foobar&endpointMapping=#endpointMapping")
.convertBodyTo(String.class).to(mock:example)

Alternative configuration, using existing endpoint mappings

For every endpoint with mapping-type beanname one bean of type CamelEndpointDispatcher with a corresponding name is required in the Registry/ApplicationContext. This bean acts as a bridge between the Camel endpoint and an existing endpoint mapping.

The use of the beanname mapping-type is primarily meant for (legacy) situations where you're already using Spring-WS and have endpoint mappings defined in a Spring XML file. The beanname mapping-type allows you to wire your Camel route into an existing endpoint mapping. When you're starting from scratch it's recommended to define your endpoint mappings as Camel URI's (as illustrated above with endpointMapping) since it requires less configuration and is more expressive. Alternatively you could use vanilla Spring-WS with the help of annotations.

An example of a route using beanname:

<camelContext xmlns="http://camel.apache.org/schema/spring">
	<route>
		<from uri="springws:beanname:QuoteEndpointDispatcher" />
		<to uri="mock:example" />
	</route>
</camelContext>

<bean id="legacyEndpointMapping" class="org.springframework.ws.server.endpoint.mapping.PayloadRootQNameEndpointMapping">
    <property name="mappings">
        <props>
            <prop key="{http://example.com/}GetFuture">FutureEndpointDispatcher</prop>
            <prop key="{http://example.com/}GetQuote">QuoteEndpointDispatcher</prop>
        </props>
    </property>
</bean>

<bean id="QuoteEndpointDispatcher" class="org.apache.camel.component.spring.ws.bean.CamelEndpointDispatcher" />
<bean id="FutureEndpointDispatcher" class="org.apache.camel.component.spring.ws.bean.CamelEndpointDispatcher" />

POJO (un)marshalling

Camel's pluggable data formats offer support for pojo/xml marshalling using a number libaries like JAXB, XStream, Castor and XMLBeans. You can use these data formats in your route to sent and receive pojo's to and from web services.

When accessing web services you can marshal the request and unmarshal the response message:

JaxbDataFormat jaxb = new JaxbDataFormat(false);
jaxb.setContextPath("com.example.model");

from("direct:example").marshal(jaxb).to("springws:http://foo.com/bar").unmarshal(jaxb);

Similarly when providing web services, you can unmarshal XML requests to POJO's and marshal the response message back to XML:

from("springws:rootqname:{http://example.com/}GetFoo?endpointMapping=#endpointMapping").unmarshal(jaxb)
.to("mock:example").marshal(jaxb);

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