String comparison in wso2 esb

Question

can any body tell me how can I check the incoming message is containing a unique string value. How to achieve this in wso2 esb. I am trying with switch, but is is not working.

My switch statement code is:

<switch xmlns:ns="http://org.apache.synapse/xsd" source="$ctx:ErrorDetail">
      <case regex="/Unable to perform XSLT transformation/">
         <log level="full" separator="**************mached****************"></log>
      </case>
      <default>
         <log level="full" separator="Not mat"></log>
      </default>
   </switch>

I am trying with this: regex=/Unable to perform XSLT transformation/.

This is the Error Detail log($ctx:ErrorDetail):

ErrorDetail = org.apache.synapse.SynapseException: Unable to perform XSLT transformation using : Value {name ='null', keyValue ='conf:/xslt/CDMXSLT.xslt'} against source XPath : s11:Body/child::*[position()=1] | s12:Body/child::*[position()=1] reason : Unable to create an OMElement using XSLT result 
    at org.apache.synapse.mediators.AbstractMediator.handleException(AbstractMediator.java:313)
    at org.apache.synapse.mediators.transform.XSLTMediator.mediate(XSLTMediator.java:194)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:77)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:47)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:131)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:196)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:77)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:47)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:131)
    at org.apache.synapse.core.axis2.ProxyServiceMessageReceiver.receive(ProxyServiceMessageReceiver.java:166)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
    at org.apache.axis2.transport.base.AbstractTransportListener.handleIncomingMessage(AbstractTransportListener.java:328)
    at org.apache.axis2.transport.jms.JMSMessageReceiver.processThoughEngine(JMSMessageReceiver.java:200)
    at org.apache.axis2.transport.jms.JMSMessageReceiver.onMessage(JMSMessageReceiver.java:122)
    at org.apache.axis2.transport.jms.ServiceTaskManager$MessageListenerTask.handleMessage(ServiceTaskManager.java:556)
    at org.apache.axis2.transport.jms.ServiceTaskManager$MessageListenerTask.run(ServiceTaskManager.java:449)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:744)
Caused by: org.apache.synapse.SynapseException: Unable to create an OMElement using XSLT result 
    at org.apache.synapse.mediators.transform.XSLTMediator.performXSLT(XSLTMediator.java:302)
    at org.apache.synapse.mediators.transform.XSLTMediator.mediate(XSLTMediator.java:191)
    ... 18 more
Caused by: org.apache.axiom.om.OMException: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[3,1]
Message: Content is not allowed in prolog.
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:296)
    at org.apache.axiom.om.impl.llom.OMDocumentImpl.getOMDocumentElement(OMDocumentImpl.java:109)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.getDocumentElement(StAXOMBuilder.java:570)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.getDocumentElement(StAXOMBuilder.java:566)
    at org.apache.synapse.util.jaxp.StreamResultBuilder.getNode(StreamResultBuilder.java:87)
    at org.apache.synapse.mediators.transform.XSLTMediator.performXSLT(XSLTMediator.java:300)
    ... 19 more
Caused by: javax.xml.stream.XMLStreamException: ParseError at [row,col]:[3,1]
Message: Content is not allowed in prolog.
    at com.sun.org.apache.xerces.internal.impl.XMLStreamReaderImpl.next(XMLStreamReaderImpl.java:598)
    at org.apache.axiom.util.stax.wrapper.XMLStreamReaderWrapper.next(XMLStreamReaderWrapper.java:225)
    at org.apache.axiom.util.stax.dialect.SJSXPStreamReaderWrapper.next(SJSXPStreamReaderWrapper.java:138)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.parserNext(StAXOMBuilder.java:681)
    at org.apache.axiom.om.impl.builder.StAXOMBuilder.next(StAXOMBuilder.java:214)
    ... 24 more

Answer 1

 <filter xmlns:ns="http://org.apache.synapse/xsd" source="json-eval($.node[0].nid)" regex="100">
      <then>
        //your business here
      </then>
      <else>
        //your business here
      </else>
  </filter>

You may compare request body parameter like this.The above sample code compares the body parameter 'nid' is equal to 100

Answer 2

Try the following regex in your switch mediator.

<case regex="*.Unable to perform XSLT transformation*.">