Mule - how to get Mule to throw an exception if XML schema validation fails

Question

I'm using a Mule schema validation filter to validate an incoming XML file against a given scheme. Below is my configuration for the schema component:

<mulexml:schema-validation-filter schemaLocations="${app.home}/classes/schemas/Library.xsd" doc:name="Schema Validation"/>

The issue I'm having is that when a file fails to validate against the schema, Mule silently blocks the message from continuing - i.e. no error/exception is thrown. Through a little experimentation I discovered that if I add the following to my log4j.properties file, I can see the 'errors' in the schema validation:

log4j.logger.org.mule.module.xml.filters.SchemaValidationFilter=DEBUG

Since these errors are 'DEBUG' level logs and no actual exception is thrown, my flow doesn't revert to the exception strategy I've configured.

So the question I have is...

Is there something I can do here to make Mule revert to an exception strategy if there is an error in the schema validation? I've included a copy below of the debug logs that I see when a file fails to validate. Thanks in advance.

DEBUG 2014-04-15 11:19:20,705 [[processes].orderInputFileConnector.receiver.01] org.mule.module.xml.filters.SchemaValidationFilter: SchemaValidationFilter rejected a message because it apparently failed to validate against the schema.
org.xml.sax.SAXParseException: cvc-pattern-valid: Value 'string' is not facet-valid with respect to pattern '[A-Z]{2}' for type 'countryISOA2'.
    at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source)
    at org.apache.xerces.util.ErrorHandlerWrapper.error(Unknown Source)
    at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
    at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
    at org.apache.xerces.impl.XMLErrorReporter.reportError(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator$XSIErrorReporter.reportError(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator.reportSchemaError(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator.elementLocallyValidType(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator.processElementContent(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator.handleEndElement(Unknown Source)
    at org.apache.xerces.impl.xs.XMLSchemaValidator.endElement(Unknown Source)
    at org.apache.xerces.jaxp.validation.DOMValidatorHelper.finishNode(Unknown Source)
    at org.apache.xerces.jaxp.validation.DOMValidatorHelper.validate(Unknown Source)
    at org.apache.xerces.jaxp.validation.DOMValidatorHelper.validate(Unknown Source)
    at org.apache.xerces.jaxp.validation.ValidatorImpl.validate(Unknown Source)
    at org.mule.module.xml.filters.SchemaValidationFilter.accept(SchemaValidationFilter.java:107)
    at org.mule.routing.MessageFilter.accept(MessageFilter.java:89)
    at org.mule.processor.AbstractFilteringMessageProcessor.process(AbstractFilteringMessageProcessor.java:42)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:95)
    at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:70)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:106)
    at org.mule.interceptor.AbstractEnvelopeInterceptor.process(AbstractEnvelopeInterceptor.java:55)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:106)
    at org.mule.processor.AbstractFilteringMessageProcessor.process(AbstractFilteringMessageProcessor.java:44)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:106)
    at org.mule.construct.AbstractPipeline$1.process(AbstractPipeline.java:112)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.chain.DefaultMessageProcessorChain.doProcess(DefaultMessageProcessorChain.java:95)
    at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:70)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper.doProcess(InterceptingChainLifecycleWrapper.java:54)
    at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:70)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper.access$001(InterceptingChainLifecycleWrapper.java:26)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper$1.process(InterceptingChainLifecycleWrapper.java:70)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper.process(InterceptingChainLifecycleWrapper.java:65)
    at org.mule.construct.AbstractPipeline$3.process(AbstractPipeline.java:204)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.chain.SimpleMessageProcessorChain.doProcess(SimpleMessageProcessorChain.java:47)
    at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:70)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.AbstractInterceptingMessageProcessorBase.processNext(AbstractInterceptingMessageProcessorBase.java:106)
    at org.mule.processor.AbstractFilteringMessageProcessor.process(AbstractFilteringMessageProcessor.java:44)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.chain.SimpleMessageProcessorChain.doProcess(SimpleMessageProcessorChain.java:47)
    at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:70)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper.doProcess(InterceptingChainLifecycleWrapper.java:54)
    at org.mule.processor.chain.AbstractMessageProcessorChain.process(AbstractMessageProcessorChain.java:70)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper.access$001(InterceptingChainLifecycleWrapper.java:26)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper$1.process(InterceptingChainLifecycleWrapper.java:70)
    at org.mule.execution.ExceptionToMessagingExceptionExecutionInterceptor.execute(ExceptionToMessagingExceptionExecutionInterceptor.java:27)
    at org.mule.execution.MessageProcessorNotificationExecutionInterceptor.execute(MessageProcessorNotificationExecutionInterceptor.java:61)
    at org.mule.execution.MessageProcessorExecutionTemplate.execute(MessageProcessorExecutionTemplate.java:47)
    at org.mule.processor.chain.InterceptingChainLifecycleWrapper.process(InterceptingChainLifecycleWrapper.java:65)
    at org.mule.transport.AbstractMessageReceiver.routeEvent(AbstractMessageReceiver.java:473)
    at org.mule.transport.AbstractMessageReceiver.routeMessage(AbstractMessageReceiver.java:226)
    at org.mule.transport.AbstractMessageReceiver.routeMessage(AbstractMessageReceiver.java:208)
    at org.mule.transport.AbstractMessageReceiver.routeMessage(AbstractMessageReceiver.java:200)
    at org.mule.transport.AbstractMessageReceiver.routeMessage(AbstractMessageReceiver.java:187)
    at org.mule.transport.file.FileMessageReceiver.moveAndDelete(FileMessageReceiver.java:560)
    at org.mule.transport.file.FileMessageReceiver.access$400(FileMessageReceiver.java:62)
    at org.mule.transport.file.FileMessageReceiver$2.process(FileMessageReceiver.java:410)
    at org.mule.transport.file.FileMessageReceiver$2.process(FileMessageReceiver.java:406)
    at org.mule.execution.ExecuteCallbackInterceptor.execute(ExecuteCallbackInterceptor.java:20)
    at org.mule.execution.HandleExceptionInterceptor.execute(HandleExceptionInterceptor.java:34)
    at org.mule.execution.HandleExceptionInterceptor.execute(HandleExceptionInterceptor.java:18)
    at org.mule.execution.BeginAndResolveTransactionInterceptor.execute(BeginAndResolveTransactionInterceptor.java:58)
    at org.mule.execution.ResolvePreviousTransactionInterceptor.execute(ResolvePreviousTransactionInterceptor.java:48)
    at org.mule.execution.SuspendXaTransactionInterceptor.execute(SuspendXaTransactionInterceptor.java:54)
    at org.mule.execution.ValidateTransactionalStateInterceptor.execute(ValidateTransactionalStateInterceptor.java:44)
    at org.mule.execution.IsolateCurrentTransactionInterceptor.execute(IsolateCurrentTransactionInterceptor.java:44)
    at org.mule.execution.ExternalTransactionInterceptor.execute(ExternalTransactionInterceptor.java:52)
    at org.mule.execution.RethrowExceptionInterceptor.execute(RethrowExceptionInterceptor.java:32)
    at org.mule.execution.RethrowExceptionInterceptor.execute(RethrowExceptionInterceptor.java:17)
    at org.mule.execution.TransactionalErrorHandlingExecutionTemplate.execute(TransactionalErrorHandlingExecutionTemplate.java:113)
    at org.mule.execution.TransactionalErrorHandlingExecutionTemplate.execute(TransactionalErrorHandlingExecutionTemplate.java:34)
    at org.mule.transport.file.FileMessageReceiver.processWithoutStreaming(FileMessageReceiver.java:405)
    at org.mule.transport.file.FileMessageReceiver.processFile(FileMessageReceiver.java:397)
    at org.mule.transport.file.FileMessageReceiver.poll(FileMessageReceiver.java:238)
    at org.mule.transport.AbstractPollingMessageReceiver.performPoll(AbstractPollingMessageReceiver.java:219)
    at org.mule.transport.PollingReceiverWorker.poll(PollingReceiverWorker.java:84)
    at org.mule.transport.PollingReceiverWorker.run(PollingReceiverWorker.java:53)
    at org.mule.work.WorkerContext.run(WorkerContext.java:311)
    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)

UPDATE

Following the answer provided by @RyanCarter (which worked), I've also found the following solution which doesn't give any errors inside of Mule Studio. It involves defining the Schema Validation Filter globally and referencing it inside a message filter like so:

<mulexml:schema-validation-filter name="myValidator".../>

<flow>          
    <message-filter throwOnUnaccepted="true">
       <filter ref="myValidator"/>
    </message-filter>

Answer 1

You can wrap the schema-validation-filter in a message-filter and set throwOnUnaccepted to "true":

<message-filter throwOnUnaccepted="true">
   <mulexml:schema-validation-filter... />
</message-filter>

You can then use an exception-strategy to handle the exception.

Answer 2

The purpose of the filter is to stop the processing if the condition is no satisfied. They usually don't throw exception and disrupt the flow. If you have to get the exception and handle it then try using errorHandler-ref property in the filter and point it to the spring bean that can handle the error.

<mulexml:schema-validation-filter  errorHandler-ref="" ></mulexml:schema-validation-filter>

Hope this helps.