How to handle exception strategy in SOAP Web Service in Mule - web-services

Question

I have a question regarding Web Service in Mule 3.3.1 CE. I have a Web Service which exposes three operation and a class that implements these operations. These operation can return a result (positive) or an Exception (AuthExeception, ValidateExeception, etc).
Thanks to SOAP Mule Component when I raise a Java Exception, the framework is able to marshall the java exception in a SOAP Fault, but if I wanted to both return a SOAP Fault to the client and handle the exception with an exception strategy in Mule (i.e sending an email), the Mule behavior it is not how can I expect.
In other word when I raise, for example, an AuthException, the flow control pass to the Exception Strategy defined and I'am not anymore able to send back to the client the SOAP Fault (AuthException).
The question is: How can I both send back the SOAP Response and handle the Exception Strategy?
Here below there is a snippet of mule xml file where the exception strategy is implemented simply with a Logger component:
<flow name="esb_consignmentFlow1" doc:name="esb_consignmentFlow1">
<http:inbound-endpoint exchange-pattern="request-response" host="${conn.host}" port="8081" doc:name="HTTP" path="sgb/consignment" />
<cxf:jaxws-service doc:name="Process SOAP Request" serviceClass="com.suzuki.sales.webservice.ProcessTriggerPortType"/>
<component class="it.aizoon.suzuki.service.implementation.TriggerConsignmentOperationsImplementation" doc:name="triggerConsignmentOperationsImpl"/>
<catch-exception-strategy doc:name="Catch Exception Strategy">
<flow-ref name="ErrorHandling" doc:name="Flow Reference"/>
</catch-exception-strategy>
</flow>
<flow name="ErrorHandling" doc:name="ErrorHandling" >
<logger level="INFO" doc:name="Logger"/>
</flow>
I've read something about Processing Strategy, but I don't know if it's the correct way.
Thank you very much for your help.

Answer 1

Here below there's my flow.xml
<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:smtp="http://www.mulesoft.org/schema/mule/smtp" xmlns:vm="http://www.mulesoft.org/schema/mule/vm" xmlns:cxf="http://www.mulesoft.org/schema/mule/cxf" xmlns:context="http://www.springframework.org/schema/context"
xmlns:http="http://www.mulesoft.org/schema/mule/http"
xmlns="http://www.mulesoft.org/schema/mule/core"
xmlns:doc="http://www.mulesoft.org/schema/mule/documentation" xmlns:spring="http://www.springframework.org/schema/beans" version="CE-3.3.1" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="
http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/cxf http://www.mulesoft.org/schema/mule/cxf/current/mule-cxf.xsd
http://www.mulesoft.org/schema/mule/smtp http://www.mulesoft.org/schema/mule/smtp/current/mule-smtp.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-current.xsd
http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd ">
<spring:beans>
<spring:bean id="consignmentProperty" class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
<!-- In questo modo riesco a definire un file di property esterno che non è in una locazione hard-coded -->
<spring:property name="ignoreUnresolvablePlaceholders" value="true"/>
<spring:property name="locations">
<spring:list>
<spring:value>classpath:esb_consignment.properties</spring:value>
<spring:value>classpath:connections.properties</spring:value>
<spring:value>classpath:email.properties</spring:value>
<!-- L'ultimo nella lista è il più generico perché sovrascrive le properties -->
</spring:list>
</spring:property>
</spring:bean>
<spring:bean id="outfaultInterceptor" class="it.aizoon.suzuki.service.interceptors.CustomSoapFaultOutInterceptor">
<spring:property name="outputQueue" value="ErrorHandler"/>
</spring:bean>
</spring:beans>
<flow name="TriggerConsignmentInterceptorService" doc:name="TriggerConsignmentInterceptorService">
<http:inbound-endpoint exchange-pattern="request-response" host="${conn.host}" port="${conn.port}" doc:name="HTTP" path="sgb/consignment" />
<cxf:jaxws-service doc:name="Process SOAP Request" serviceClass="com.suzuki.sales.webservice.ProcessTriggerPortType">
<cxf:outFaultInterceptors>
<spring:ref bean="outfaultInterceptor"/>
</cxf:outFaultInterceptors>
</cxf:jaxws-service>
<component class="it.aizoon.suzuki.service.implementation.TriggerConsignmentOperationsImplementation" doc:name="triggerConsignmentOperationsImpl"/>
</flow>
<flow name="ErrorHandler" doc:name="ErrorHandler">
<vm:inbound-endpoint exchange-pattern="one-way" path="ErrorHandler" doc:name="Error Handler"/>
<logger message="PAYLOAD: #[message.payload]" level="INFO" doc:name="Payload"/>
<set-payload value="Tipo di Eccezione: #[message.payload]" doc:name="Set Payload"/>
<smtp:outbound-endpoint host="${smtp.host}"
from="${email.fromAddress}"
to="${email.toAddress}"
subject="${email.subject}"
responseTimeout="10000"
doc:name="Email Notification"/>
<logger message="EMAIL SENT" level="INFO" doc:name="Result"/>
<catch-exception-strategy doc:name="Catch Exception Strategy">
<logger message="ERRORE INVIO EMAIL" level="INFO" doc:name="Logger"/>
</catch-exception-strategy>
</flow>
</mule>
Here below there's the interceptor which handle the SOAP response and the exception strategy
package it.aizoon.suzuki.service.interceptors;
import javax.xml.bind.UnmarshalException;
import org.apache.cxf.interceptor.Fault;
import org.apache.cxf.message.Message;
import org.apache.cxf.phase.AbstractPhaseInterceptor;
import org.apache.cxf.phase.Phase;
import org.mule.DefaultMuleMessage;
import org.mule.api.MuleContext;
import org.mule.api.MuleEvent;
import org.mule.api.MuleException;
import org.mule.api.client.MuleClient;
import org.mule.api.context.MuleContextAware;
import org.mule.module.cxf.CxfConstants;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.suzuki.sales.webservice.AuthenticationFailedException;
import com.suzuki.sales.webservice.ValidationFailedException;
public class CustomSoapFaultOutInterceptor extends AbstractPhaseInterceptor implements MuleContextAware{
private static final Logger logger = LoggerFactory.getLogger(CustomSoapFaultOutInterceptor.class);
private String outputQueue;
private MuleContext context;
public CustomSoapFaultOutInterceptor() {
// TODO Auto-generated constructor stub
super(Phase.MARSHAL);
}
#Override
public void setMuleContext(MuleContext context) {
// TODO Auto-generated method stub
this.context = context;
}
#Override
public void handleMessage(Message message) throws Fault {
// TODO Auto-generated method stub
MuleClient client = context.getClient();
MuleEvent event = (MuleEvent) message.getExchange().get(CxfConstants.MULE_EVENT);
DefaultMuleMessage muleMessage = (DefaultMuleMessage) event.getMessage();
Throwable genericExec = message.getContent(Exception.class).getCause();
Throwable exception = null;
if(genericExec instanceof ValidationFailedException){
exception = (ValidationFailedException) genericExec;
}else if(genericExec instanceof AuthenticationFailedException){
exception = (AuthenticationFailedException) genericExec;
}else if(genericExec instanceof UnmarshalException){
exception = (UnmarshalException) genericExec;
}
try {
muleMessage.setPayload(exception);
client.send("vm://" + getOutputQueue(), muleMessage);
} catch (MuleException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public String getOutputQueue() {
return outputQueue;
}
public void setOutputQueue(String outputQueue) {
this.outputQueue = outputQueue;
}
public MuleContext getContext() {
return context;
}
public void setContext(MuleContext context) {
this.context = context;
}
}

Answer 2

Mule suppresses the exception beyond the exception strategy.
For this scenario where you want to handle the exception as well as send it as reply, a custom transformer is to be provided to prepare the soap fault with the exception and then set it as payload in the exception strategy flow.
<flow name="ErrorHandling" doc:name="ErrorHandling" >
<logger level="INFO" doc:name="Logger"/>
<custom-transformer class="com.example.service.ErrorTransformer"></custom-transformer>
</flow>
And a transformer to prepare the error message.
#Override
public Object transformMessage(MuleMessage message, String outputEncoding)
throws TransformerException {
String exceptionMessage = message.getExceptionPayload().getException().getCause().getMessage() ;
String outputMessage = "<soap:Fault xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\"> " +
" <faultcode>soap:Server</faultcode> " +
"<faultstring>" + exceptionMessage + "</faultstring> " +
"</soap:Fault>";
return outputMessage;
}
Note: This is a sample transformer. Customize it for your scenario.