Custom Exception Strategy in Mule





Custom Exception Strategy in Mule



Custom exception strategy handles the exception having logic in custom java class.When exception occurs the java class executes and handles the exception.



Mule provides numerous options for handling errors. Faults that occur within Mule are referred to as exceptions; when an activity in your Mule instance fails, Mule throws an exception. To manage these exceptions, Mule allows you to configure exception strategies.


Mule’s default exception strategy — which implicitly applies to all Mule applications — manages errors (that is. thrown exceptions) in Mule flows. When your flows require more sophisticated error management, you can implement one or more exception strategies to construct precise, efficient protocols for handling errors.

flow of custom exception strategy :




Custom strategy configuration settings :

Just we need to give path of java class in settings
.


Custom java class located in src/main/java :


package test_customexception;

import org.mule.api.MuleEvent;
import org.mule.api.MuleException;
import org.mule.api.MuleMessage;
import org.mule.api.exception.MessagingExceptionHandler;


public class CustomExc implements MessagingExceptionHandler {


 String enableNotifications;

 String logException;


  public String getEnableNotifications() {

  return enableNotifications;

 }


  public void setEnableNotifications(String enableNotifications) {

  this.enableNotifications = enableNotifications;

 }


  public String getLogException() {

  return logException;

 }


  public void setLogException(String logException) {

  this.logException = logException;

 }

  @Override

 public MuleEvent handleException(Exception exception, MuleEvent event) {

  event.setStopFurtherProcessing(true);


  System.out.println("Exception message : " + exception);

  return event;

 }

}


URL : http://localhost:8085/api/customexc
Method : POST


Input : 



Output : 

java.io.IOException: Unexpected symbol: END_OBJECT (javax.xml.stream.XMLStreamException) (org.mule.api.transformer.TransformerException).

XML project code :


<?xml version="1.0" encoding="UTF-8"?>
<mule xmlns:json="http://www.mulesoft.org/schema/mule/json" xmlns:http="http://www.mulesoft.org/schema/mule/http" xmlns:apikit="http://www.mulesoft.org/schema/mule/apikit" 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" 
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/json http://www.mulesoft.org/schema/mule/json/current/mule-json.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/apikit http://www.mulesoft.org/schema/mule/apikit/current/mule-apikit.xsd">
    <http:listener-config name="HTTP_Listener_Configuration" host="0.0.0.0" port="8085" basePath="/api" doc:name="HTTP Listener Configuration"/>
    <flow name="test_mappingexceptionFlow">
        <http:listener config-ref="HTTP_Listener_Configuration" path="/customexc" doc:name="HTTP"/>
        <json:json-to-xml-transformer doc:name="JSON to XML"/>
        <custom-exception-strategy class="test_customexception.CustomExc" doc:name="Custom Exception Strategy"/>
    </flow>
</mule>