In this post I show you how I setup a little test to see if and how easy I could manage to route the traffic to and from a web service through Mule ESB. The business case for this is an issue that one of our customers ran into when using web services. In a program hundreds of calls are done in a relative short period. Most of the time this isn’t a problem but sometimes vague issues occur. To get a better insight in this issue I want to put Mule in the middle so I can log the request and response and hopefully get a better idea about what is sent across the line. This is called the Web Service Proxy pattern and is commonly used to validate and audit the web service calls. For more background info about this pattern see this article.

To get started I downloaded the Mule Standalone edition here and installed it. That isn’t very hard, just untar the thing and set the MULE_HOME property. Go to the bin directory and give ‘./mule’ and off you go (except for a warning when running on MacOS 64-bit, but it doesn’t seem to harm so far…):

To create a test web service I setup a MockService in SoapUI. Like this:

All you need is a WSDL available. I just picked one from a previous project for testing purposes. With this MockService started you can fire your SOAP requests and will receive a (predefined) response from the MockService:

Next step is create a new Mule project (I still favor Maven above the Mule Studio):

• create new Maven project with

mvn mule-project-archetype:create -DartifactId=WSProxy -DmuleVersion=3.1.2

• Set up the WS Proxy

To create WS Proxy I followed the description here
Note: to make use of the pre-defined ‘pattern’ you must add the following dependency to the pom:

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<dependency> <groupId>org.mule.patterns</groupId> <artifactId>mule-patterns-all</artifactId> <version>${mule.version}</version> <scope>provided</scope> </dependency>

My Mule config file looks like this:

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<?xml version="1.0" encoding="UTF-8"?> <mule xmlns="http://www.mulesoft.org/schema/mule/core" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:pattern="http://www.mulesoft.org/schema/mule/pattern" xsi:schemaLocation=" http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/3.1/mule.xsd http://www.mulesoft.org/schema/mule/pattern http://www.mulesoft.org/schema/mule/pattern/3.1/mule-pattern.xsd"> <description> Proxies a Web Service </description> <custom-transformer name="my-transformer" class="nl.redstream.proxy.wsproxy.MyTransformer" /> <object-to-string-transformer name="ObjectToStringTransformer" />   <pattern:web-service-proxy name="my-order-ws-proxy" inboundAddress="http://Pascal-Almas-MacBook-Pro.local:8090/my-order" responseTransformer-refs="ObjectToStringTransformer my-transformer" outboundAddress="http://Pascal-Almas-MacBook-Pro.local:8088/mockDataServiceSoapBinding" /> </mule>

• Fire up the proxy

To run the Mule application just make sure your Mule installation is running and in your project execute the command ‘mvn clean install’
You should see a message in your Mule console like this:

Now we can put the proxy at work by redirecting the SoapUI request to the url: http://Pascal-Almas-MacBook-Pro.local:8090/my-order. It should the be forwarded to the original url and the translator I put in between should output the content to the Mule console:

However if you try this for the first time big chance you will run into this issue (at least I did). To get around this issue modify the soapUI settings like this: