Spring Web Services

Spring Web Services Component

Available as of Camel 2.6

The spring-ws: 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>

URI format

The URI scheme for this component is as follows

spring-ws:[mapping-type:]address[?options]

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

As a consumer the address should contain a value relevant to the specified mapping-type (e.g. a SOAP action, XPath expression). As a producer 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

Message headers

Accessing web services

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

from("direct:example").to("spring-ws:http://foo.com/bar")

And sent a message:

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

Remember if it's a SOAP service you're calling you don't have to include SOAP tags. Spring-WS will perform the XML-to-SOAP marshaling.

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("spring-ws: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 SOAP headers

Available as of Camel 2.11.1

You can provide the SOAP header(s) as a Camel Message header when sending a message to a spring-ws endpoint, for example given the following SOAP header in a String

String body = ...
String soapHeader = "<h:Header xmlns:h=\"http://www.webserviceX.NET/\"><h:MessageID>1234567890</h:MessageID><h:Nested><h:NestedID>1111</h:NestedID></h:Nested></h:Header>";

We can set the body and header on the Camel Message as follows:

exchange.getIn().setBody(body);
exchange.getIn().setHeader(SpringWebserviceConstants.SPRING_WS_SOAP_HEADER, soapHeader);

And then send the Exchange to a spring-ws endpoint to call the Web Service.

Likewise the spring-ws consumer will also enrich the Camel Message with the SOAP header.

For an example see this unit test.

The header and attachment propagation

Spring WS Camel supports propagation of the headers and attachments into Spring-WS WebServiceMessage response since version 2.10.3. The endpoint will use so called "hook" the MessageFilter (default implementation is provided by BasicMessageFilter) to propagate the exchange headers and attachments into WebServiceMessage response. Now you can use

exchange.getOut().getHeaders().put("myCustom","myHeaderValue")
exchange.getIn().addAttachment("myAttachment", new DataHandler(...))

Note: If the exchange header in the pipeline contains text, it generates Qname(key)=value attribute in the soap header. Recommended is to create a QName class directly and put into any key into header.

How to use MTOM attachments

The BasicMessageFilter provides all required information for Apache Axiom in order to produce MTOM message. If you want to use Apache Camel Spring WS within Apache Axiom, here is an example:
1. Simply define the messageFactory as is bellow and Spring-WS will use MTOM strategy to populate your SOAP message with optimized attachments.

<bean id="axiomMessageFactory"
class="org.springframework.ws.soap.axiom.AxiomSoapMessageFactory">
<property name="payloadCaching" value="false" />
<property name="attachmentCaching" value="true" />
<property name="attachmentCacheThreshold" value="1024" />
</bean>

2. Add into your pom.xml the following dependencies

<dependency>
<groupId>org.apache.ws.commons.axiom</groupId>
<artifactId>axiom-api</artifactId>
<version>1.2.13</version>
</dependency>
<dependency>
<groupId>org.apache.ws.commons.axiom</groupId>
<artifactId>axiom-impl</artifactId>
<version>1.2.13</version>
<scope>runtime</scope>
</dependency>

3. Add your attachment into the pipeline, for example using a Processor implementation.

private class Attachement implements Processor {
public void process(Exchange exchange) throws Exception
{ exchange.getOut().copyFrom(exchange.getIn()); File file = new File("testAttachment.txt"); exchange.getOut().addAttachment("test", new DataHandler(new FileDataSource(file)));	 }
}

4. Define endpoint (producer) as ussual, for example like this:

from("direct:send")
.process(new Attachement())
.to("spring-ws:http://localhost:8089/mySoapService?soapAction=mySoap&messageFactory=axiomMessageFactory");

5. Now, your producer will generate MTOM message with otpmized attachments.

The custom header and attachment filtering

If you need to provide your custom processing of either headers or attachments, extend existing BasicMessageFilter and override the appropriate methods or write a brand new implementation of the MessageFilter interface.
To use your custom filter, add this into your spring context:

You can specify either a global a or a local message filter as follows:
a) the global custom filter that provides the global configuration for all Spring-WS endpoints

 
<bean id="messageFilter" class="your.domain.myMessageFiler" scope="singleton" />

or
b) the local messageFilter directly on the endpoint as follows:

to("spring-ws:http://yourdomain.com?messageFilter=#myEndpointSpecificMessageFilter");

For more information see CAMEL-5724

If you want to create your own MessageFilter, consider overriding the following methods in the default implementation of MessageFilter in class BasicMessageFilter:

protected void doProcessSoapHeader(Message inOrOut, SoapMessage soapMessage)
{your code /*no need to call super*/ }

protected void doProcessSoapAttachements(Message inOrOut, SoapMessage response)
{ your code /*no need to call super*/ }

Using a custom MessageSender and MessageFactory

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

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

Spring configuration:

<!-- authenticate using HTTP Basic Authentication -->
<bean id="messageSender" class="org.springframework.ws.transport.http.HttpComponentsMessageSender">
	<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>
	</property>
	<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 "Implementing the Endpoint" is handled by this component (specifically paragraph 3.6.2 "Routing the Message to the Endpoint" is where CamelEndpointMapping comes in). Also don't forget to check out the Spring Web Services Example included in the Camel distribution.

Endpoint mapping in routes

With the XML configuration in-place you can now use Camel's DSL to define what web service requests 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("spring-ws: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("spring-ws: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("spring-ws: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("spring-ws: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 like PayloadRootQNameEndpointMapping.

An example of a route using beanname:

<camelContext xmlns="http://camel.apache.org/schema/spring">
	<route>
		<from uri="spring-ws: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 libraries such as JAXB, XStream, JibX, 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("spring-ws: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("spring-ws:rootqname:{http://example.com/}GetFoo?endpointMapping=#endpointMapping").unmarshal(jaxb)
.to("mock:example").marshal(jaxb);