how to retrieve Schema Validation error result in mule-esb

Question

In Mule, am trying to validate a XML against XSD.

In my flow am using schema-validation-filter component nested with in message-filter component and working as expected.

but my question is, if XML fails, how do I capture the error details in logger component and based on results in need to navigate the flow.

Basically am looking for a MEL to print the error description on the console

Note: "returnResult" is set to false, because i need, to do further operations on the XML.

here is my configuration Flow:

<?xml version="1.0" encoding="UTF-8"?>

<mule xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:file="http://www.mulesoft.org/schema/mule/file" xmlns:jms="http://www.mulesoft.org/schema/mule/jms" xmlns:tracking="http://www.mulesoft.org/schema/mule/ee/tracking" xmlns:mulexml="http://www.mulesoft.org/schema/mule/xml" xmlns:vm="http://www.mulesoft.org/schema/mule/vm" 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="EE-3.4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="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
http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
http://www.mulesoft.org/schema/mule/xml http://www.mulesoft.org/schema/mule/xml/current/mule-xml.xsd
http://www.mulesoft.org/schema/mule/ee/tracking http://www.mulesoft.org/schema/mule/ee/tracking/current/mule-tracking-ee.xsd
http://www.mulesoft.org/schema/mule/jms http://www.mulesoft.org/schema/mule/jms/current/mule-jms.xsd
http://www.mulesoft.org/schema/mule/file http://www.mulesoft.org/schema/mule/file/current/mule-file.xsd
http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd">
    <mulexml:schema-validation-filter schemaLocations="D:\MuleStudio\workspace\exceptiontest\src\test\resources\sample.xsd" returnResult="false" name="Schema_Validation" doc:name="Schema Validation"/>

    <flow name="ExceptionTestFlow2" doc:name="ExceptionTestFlow2">
        <http:inbound-endpoint exchange-pattern="one-way" host="localhost" port="8081" path="dataQ" doc:name="HTTP"/>
        <expression-filter expression="#[message.payload != '/favicon.ico' ]" doc:name="Expression does't allow /favicon.ico"/>
        <set-payload value="&lt;data&gt;
 &lt;books&gt;
  &lt;book edition='1.0'&gt;
   &lt;auth&gt; auth&lt;/auth&gt;
   &lt;title&gt;title&lt;/title&gt;
   &lt;pulbisher&gt;pub&lt;/pulbisher&gt;
  &lt;/book&gt;
 &lt;/books&gt;
&lt;/data&gt;
" doc:name="XML is set as payload tp the current flow"/>
        <logger message="::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Actual Flow Started :::::::::::::::::::::::::::::::::::::::::::::::::" level="INFO" doc:name="indicates Actual Flow Started Logger"/>
        <logger message="paylad is  :::: #[payload] :::::" level="INFO" doc:name="Prints current Payload"/>
        <vm:outbound-endpoint exchange-pattern="one-way" path="dataQ" doc:name="VMQ_stores current xml which needs to be validated_senderQ"/>
    </flow>
    <flow name="ExceptionTestFlow1" doc:name="ExceptionTestFlow1">
        <vm:inbound-endpoint exchange-pattern="one-way" path="dataQ" doc:name="VMQ_stores current xml which needs to be validated_receiverQ"/>
        <logger message="::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: Flow Started :::::::::::::::::::::::::::::::::::::::::::::::::" level="DEBUG" doc:name="indicates Flow Started Logger"/>
        <message-filter  doc:name="filter to validate xml against xsd" throwOnUnaccepted="true">
            <filter ref="Schema_Validation"/>
        </message-filter>
        <logger message=" validation is true and the payload is :::: #[payload]" level="INFO" doc:name="current Payload"/>
        <logger message="::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::: End of Actual Flow:::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::::" level="INFO" doc:name="indicates Flow End Logger"/>
        <choice-exception-strategy doc:name="Choice Exception Strategy">
            <catch-exception-strategy when="exception.causedBy(org.mule.api.routing.filter.FilterUnacceptedException)" enableNotifications="false" doc:name="FilterUnacceptedException">
                <logger message="::::::::::::::::::::::::::::::::::: in FilterUnacceptedException :::::::::::::::::::::::::" level="ERROR" doc:name="indicates FilterUnacceptedException Flow Started Logger"/>
                <set-payload value="The request cannot be processed, the error is #[exception.getMessage()]" doc:name="Set Payload"/> <!-- [1] -->
                <set-property propertyName="http.status" value="500" doc:name="Property"/>
                <logger message=":::::::::::: end of FilterUnacceptedException with a payload as  #[message.payload] ::::::::::::" level="INFO" doc:name="indicates FilterUnacceptedException End Logger"/> <!-- [2] -->
            </catch-exception-strategy>
            <catch-exception-strategy enableNotifications="false" doc:name="default">
                <logger message=":::::::::::::::::::::: in default::::::::::::::::::::::::::::" level="ERROR" doc:name="indicates defaultException Flow Started Logger"/>
                <set-payload value="The request cannot be processed, the error is #[exception.getSummaryMessage()]" doc:name="Set Payload"/>
                <logger message="::::::::::::::::::::::::::::::::::::::::::::: END of Default Exception :::::::::::::::::::::::::::::::::::" level="INFO" doc:name="indicates DefaultException End Logger"/> <!-- [1] -->
 <!-- [2] -->
            </catch-exception-strategy>
        </choice-exception-strategy>
    </flow>
    <flow name="Flow_If_XML_not_valid" doc:name="Flow_If_XML_not_valid">
        <logger message=":::::::::::::::::::::::::::: #[payload] :::::::::::::: onThrow ::::::" level="INFO" doc:name="Should Print  error description"/>
    </flow>
</mule>

Have added an exception strategy that gives the following output:

Message has been rejected by filter. Message payload is of type: String Code : MULE_ERROR--2

Exception stack is: 1. Message has been rejected by filter. Message payload is of type: String (org.mule.api.routing.filter.FilterUnacceptedException) ... http://www.mulesoft.org/docs/site/current3/apidocs/org/mule/api/routing/filter/FilterUnacceptedException.html)..

I need to be able to pinpoint which field is causing the problem.

In the exception caught by your strategy, can't you find the root cause? i.e the reason why XSD validation failed? — David Dossot

julien julien · Accepted Answer · 2013-11-06T17:06:06

package what.the.fuck.customFilter;

import java.io.IOException;

import javax.xml.transform.Source;
import javax.xml.transform.dom.DOMResult;

import org.mule.api.MuleMessage;
import org.mule.api.transport.PropertyScope;
import org.mule.module.xml.filters.SchemaValidationFilter;
import org.xml.sax.SAXException;

public class SchemaValidationFilterWithTrace extends SchemaValidationFilter {

    public final static String SAX_ERROR_PROPERTIES = "SAX_ERROR_PROPERTIES";
    public final static boolean RETURN_RESULT = false;
    public final static String SCHEMA_LOCATION = "what.the.fuck.xsd";

    public SchemaValidationFilterWithTrace(){
        super();
        super.setReturnResult(false);
        super.setSchemaLocations(SCHEMA_LOCATION);
    }


    /**
     * Accepts the message if schema validation passes.
     * 
     * @param message The message.
     * @return Whether the message passes schema validation.
     */
    @Override
    public boolean accept(MuleMessage message)
    {
        Source source;
        try
        {
            source = loadSource(message);
        }
        catch (Exception e)
        {
            if (e instanceof RuntimeException)
            {
                throw (RuntimeException) e;
            }

            if (logger.isInfoEnabled())
            {
                logger.info("SchemaValidationFilter rejected a message because there was a problem interpreting the payload as XML.", e);
            }
            return false;
        }

        if (source == null)
        {
            if (logger.isInfoEnabled())
            {
                logger.info("SchemaValidationFilter rejected a message because the XML source was null.");
            }
            return false;
        }


        DOMResult result = null;

        try
        {
            if (super.isReturnResult()) 
            {
                result = new DOMResult();
                createValidator().validate(source, result);
            }
            else 
            {
                createValidator().validate(source);
            }
        }
        catch (SAXException e)
        {
            message.setProperty(SAX_ERROR_PROPERTIES, e.getMessage(), PropertyScope.OUTBOUND);
            if (logger.isDebugEnabled())
            {
                logger.debug(
                    "SchemaValidationFilter rejected a message because it apparently failed to validate against the schema.",
                    e);
            }
            return false;
        }
        catch (IOException e)
        {
            if (logger.isInfoEnabled())
            {
                logger.info(
                    "SchemaValidationFilter rejected a message because there was a problem reading the XML.",
                    e);
            }
            return false;
        }
        finally 
        {
            if (result != null && result.getNode() != null)
            {
                message.setPayload(result.getNode());
            }
        }

        if (logger.isDebugEnabled())
        {
            logger.debug("SchemaValidationFilter accepted the message.");
        }

        return true;
    }

}

how to retrieve Schema Validation error result in mule-esb

3 Answers