To invoke a Web Service upon sending a message to a channel, there are two options - both of which build upon the Spring Web Services project: SimpleWebServiceOutboundGateway and MarshallingWebServiceOutboundGateway. The former will accept either a String or javax.xml.transform.Source as the message payload. The latter provides support for any implementation of the Marshaller and Unmarshaller interfaces. Both require a Spring Web Services DestinationProvider for determining the URI of the Web Service to be called.

 simpleGateway = new SimpleWebServiceOutboundGateway(destinationProvider);

 marshallingGateway = new MarshallingWebServiceOutboundGateway(destinationProvider, marshaller);

For more detail on the inner workings, see the Spring Web Services reference guide’s chapter covering client access as well as the chapter covering Object/XML mapping.

To send a message to a channel upon receiving a Web Service invocation, there are two options again: SimpleWebServiceInboundGateway and MarshallingWebServiceInboundGateway. The former will extract a javax.xml.transform.Source from the WebServiceMessage and set it as the message payload. The latter provides support for implementation of the Marshaller and Unmarshaller interfaces. If the incoming web service message is a SOAP message the SOAP Action header will be added to the headers of the`Message` that is forwarded onto the request channel.

 simpleGateway = new SimpleWebServiceInboundGateway();
 simpleGateway.setRequestChannel(forwardOntoThisChannel);
 simpleGateway.setReplyChannel(listenForResponseHere); //Optional

 marshallingGateway = new MarshallingWebServiceInboundGateway(marshaller);
 //set request and optionally reply channel

Both gateways implement the Spring Web Services MessageEndpoint interface, so they can be configured with a MessageDispatcherServlet as per standard Spring Web Services configuration.

For more detail on how to use these components, see the Spring Web Services reference guide’s chapter covering creating a Web Service. The chapter covering Object/XML mapping is also applicable again.

To include the SimpleWebServiceInboundGateway and MarshallingWebServiceInboundGateway configurations to the Spring WS infrastructure you should add the EndpointMapping definition between MessageDispatcherServlet and the target MessageEndpoint implementations like you do that with normal Spring WS application. For this purpose (from Spring Integration perspective), the Spring WS provides these convenient EndpointMapping implementations:

The beans for these classes must be specified in the application context referencing to the SimpleWebServiceInboundGateway and/or MarshallingWebServiceInboundGateway bean definitions according to the WS mapping algorithm.

Please, refer to the Endpoint mappings for the more information.

To configure an outbound Web Service Gateway, use the "outbound-gateway" element from the "ws" namespace:

<int-ws:outbound-gateway id="simpleGateway"
                     request-channel="inputChannel"
                     uri="http://example.org"/>

To set up an inbound Web Service Gateway, use the "inbound-gateway":

<int-ws:inbound-gateway id="simpleGateway"
                    request-channel="inputChannel"/>

To use Spring OXM Marshallers and/or Unmarshallers, provide bean references. For outbound:

<int-ws:outbound-gateway id="marshallingGateway"
                     request-channel="requestChannel"
                     uri="http://example.org"
                     marshaller="someMarshaller"
                     unmarshaller="someUnmarshaller"/>

And for inbound:

<int-ws:inbound-gateway id="marshallingGateway"
                    request-channel="requestChannel"
                    marshaller="someMarshaller"
                    unmarshaller="someUnmarshaller"/>

For either outbound gateway type, a "destination-provider" attribute can be specified instead of the "uri" (exactly one of them is required). You can then reference any Spring Web Services DestinationProvider implementation (e.g. to lookup the URI at runtime from a registry).

For either outbound gateway type, the "message-factory" attribute can also be configured with a reference to any Spring Web Services WebServiceMessageFactory implementation.

For the simple inbound gateway type, the "extract-payload" attribute can be set to false to forward the entire WebServiceMessage instead of just its payload as a Message to the request channel. This might be useful, for example, when a custom Transformer works against the WebServiceMessage directly.

For all URI-schemes supported by Spring Web Services (URIs and Transports) <uri-variable/> substitution is provided:

<ws:outbound-gateway id="gateway" request-channel="input"
        uri="http://springsource.org/{foo}-{bar}">
    <ws:uri-variable name="foo" expression="payload.substring(1,7)"/>
    <ws:uri-variable name="bar" expression="headers.x"/>
</ws:outbound-gateway>

<ws:outbound-gateway request-channel="inputJms"
        uri="jms:{destination}?deliveryMode={deliveryMode}&amp;priority={priority}"
        message-sender="jmsMessageSender">
    <ws:uri-variable name="destination" expression="headers.jmsQueue"/>
    <ws:uri-variable name="deliveryMode" expression="headers.deliveryMode"/>
    <ws:uri-variable name="priority" expression="headers.jms_priority"/>
</ws:outbound-gateway>

If a DestinationProvider is supplied, variable substitution is not supported and a configuration error will result if variables are provided.

Controlling URI Encoding

By default, the URL string is encoded (see UriComponentsBuilder) to the URI object before sending the request. In some scenarios with a non-standard URI it is undesirable to perform the encoding. Since version 4.1 the <ws:outbound-gateway/> provides an encode-uri attribute. To disable encoding the URL, this attribute should be set to false (by default it is true). If you wish to partially encode some of the URL, this can be achieved using an expression within a <uri-variable/>:

<ws:outbound-gateway url="http://somehost/%2f/fooApps?bar={param}" encode-uri="false">
          <http:uri-variable name="param"
            expression="T(org.apache.commons.httpclient.util.URIUtil)
                                             .encodeWithinQuery('Hello World!')"/>
</ws:outbound-gateway>

Note, encode-uri is ignored, if DestinationProvider is supplied.

The Spring Integration WebService Gateways will map the SOAP Action header automatically. It will be copied by default to and from Spring Integration MessageHeaders using the DefaultSoapHeaderMapper.

Of course, you can pass in your own implementation of SOAP specific header mappers, as the gateways have respective properties to support that.

Any user-defined SOAP headers will NOT be copied to or from a SOAP Message, unless explicitly specified by the requestHeaderNames and/or replyHeaderNames properties of the DefaultSoapHeaderMapper.

When using the XML namespace for configuration, these properties can be set using the mapped-request-headers and mapped-reply-headers, or a custom mapper can be provided using the header-mapper attribute.

Starting with version 4.1, the AbstractHeaderMapper (a DefaultSoapHeaderMapper superclass) allows the NON_STANDARD_HEADERS token to be configured for the requestHeaderNames and/or replyHeaderNames properties (in addition to existing STANDARD_REQUEST_HEADERS and STANDARD_REPLY_HEADERS) to map all user-defined headers. Note, it is recommended to use the combination like this STANDARD_REPLY_HEADERS, NON_STANDARD_HEADERS instead of a *, to avoid mapping of request headers to the reply.

Starting with version 4.3, patterns in the header mappings can be negated by preceding the pattern with !. Negated patterns get priority, so a list such as STANDARD_REQUEST_HEADERS,foo,ba*,!bar,!baz,qux,!foo will NOT map foo (nor bar nor baz); the standard headers plus bad, qux will be mapped.

Inbound SOAP headers (request headers for the inbound gateway, reply-headers for the outbound gateway) are mapped as SoapHeaderElement objects. The contents can be explored by accessing the Source:

<soapenv:Envelope xmlns:soapenv="http://schemas.xmlsoap.org/soap/envelope/">
    <soapenv:Header>
        <auth>
            <username>user</username>
            <password>pass</password>
        </auth>
        <bar>BAR</bar>
        <baz>BAZ</baz>
        <qux>qux</qux>
    </soapenv:Header>
    <soapenv:Body>
        ...
    </soapenv:Body>
</soapenv:Envelope>

If mapped-request-headers is "auth, ba*", the auth, bar and baz headers are mapped but qux is not.

...
SoapHeaderElement header = (SoapHeaderElement) headers.get("auth");
DOMSource source = (DOMSource) header.getSource();
NodeList nodeList = source.getNode().getChildNodes();
assertEquals("username", nodeList.item(0).getNodeName());
assertEquals("user", nodeList.item(0).getFirstChild().getNodeValue());
...