The document discusses validating SOAP requests in Mule by using a schema validation filter. The filter allows validating a SOAP request against an XSD schema file. If invalid, a custom error message can be returned. The code example shows adding the filter to the flow before the SOAP service. This validates requests and routes invalid ones to a subflow to return the error.

1. Validating a SOAP Request in
Mule

2. We often come across SOAP web services in our project and
often face different challenges in handling SOAP web
services. One such challenge is SOAP request validation.
.

3. In Mule ESB we can expose a SOAP webservices and can
handle the request validation in very simple way.
.

4. Yes, I am talking about using message filter to validate a
SOAP request against a given XSD file
In simple words if we have the XSD file of
web service we can validate the request of
the web service against that XSD using a
schema validation filter in Mule..

5. Let’s see how…
Let consider we have a SOAP webs ervice exposed in Mule by
following way :-

6. Now, if we want to validate the request with an XSD file of the web
service and want to throw a custom message in case if the SOAP
request is invalid or incorrect, we need to use schema
validation filter

7. So after adding schema validation filter in our flow, our flow looks
like the following

8. We can also add a subflow which will throw custom message if the
SOAP request is invalid as follow :-

9. So, if we test the webservice with a wrong SOAP request in SoapUI
we will get a custom message :-

10. This is how the flow works:-

11. <mulexml:schema-validation-filter name="Schema_Validation"
schemaLocations="MainData.xsd" returnResult="true" doc:name="Schema Validation" />
The code:-
You need to use schema validation filter which will refer to your
XSD files for validating a SOAP request as follows:-
The Schema Validation Filter uses the JAXP libraries to validate a message against
a schema. You must provide the path, file name, and extension of the schema or
schemas in the Schema Locations property.

12. <flow name="ServiceFlow" doc:name="ServiceFlow">
<http:inbound-endpoint exchange-pattern="request-response" host="localhost"
port="8082" path="mainData" doc:name="HTTP"/>
<message-filter onUnaccepted="ValidationFailFlow" doc:name="filter to validate xml
against xsd" throwOnUnaccepted="true" >
<filter ref="Schema_Validation"/>
</message-filter>
<cxf:jaxws-service validationEnabled="true"
serviceClass="com.test.services.schema.maindata.v1.MainData" doc:name="SOAP"/>
<component class="com.test.services.schema.maindata.v1.Impl.MainDataImpl"
doc:name="JavaMain_ServiceImpl"/>
</flow>
A code snipped of the Mule config:-

13. To get the full code access for implementing a SOAP Request
validator in Mule, please visit :-
http://anirbansenchowdhary.com/blog/?p=131
You can also visit Mule documentation on Schema Validation :-
http://www.mulesoft.org/documentation/display/current/Schema+
Validation+Filter