Exposing web services - 6.3

Talend ESB Mediation Developer Guide

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6.3
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Talend Data Fabric
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for ESB
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task
Design and Development
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Talend ESB

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.MessageDispatcherServl
et</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?endpointMapp
ing=#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=#endpointMapp
ing")
.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.

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="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" />