Catch Exception Strategy in Mule

  Catch Exception Strategy in Mule





You can define a catch exception strategy to customize the way Mule handles messages with errors. A catch exception strategy catches all exceptions thrown within its parent flow and processes them, thereby overriding Mule’s implicit default exception strategy.

Mule’s catch exception strategy behavior is similar to a Java catch block, except that you cannot throw a new exception or catch another exception within a catch exception strategy.

When to Use :

Use a catch exception strategy to design a unique strategy for handling a message that contains an error. Further, you can use a catch exception strategy to:

Avoid propagating exceptions to inbound connectors

Avoid propagating exceptions to parent flows via Flow Reference Components

Ensure that a transaction processed by the flow is not rolled back when an error occurs (that is, the transaction is never “rolled back” to reattempt processing; Mule commits the transaction.)

flow of catch exception strategy


If exception occurs than catch exception strategy catches the exception set the status code by property file and display user defined message by set payload.

property transformer view :


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

Input : 

Here i have sent wrong json input so exception will occur and handled by catch exception strategy.


Output :


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="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/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd
http://www.mulesoft.org/schema/mule/json http://www.mulesoft.org/schema/mule/json/current/mule-json.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_catchexceptionFlow">
        <http:listener config-ref="HTTP_Listener_Configuration" path="/catch" doc:name="HTTP"/>
        <json:json-to-xml-transformer doc:name="JSON to XML"/>
        <set-payload value="#[payload]" doc:name="Set Payload"/>
        <catch-exception-strategy doc:name="Catch Exception Strategy">
            <set-property propertyName="http.status" value="400" doc:name="Property"/>
            <set-payload value="Input is not correct" doc:name="Set Payload"/>
        </catch-exception-strategy>
    </flow>
</mule>








Please go through below tutorials:


Mule 4 Tutorials

DEPLOY TO CLOUDHUB C4E CLIENT ID ENFORCEMENT CUSTOM POLICY RABBIT MQ INTEGRATION
XML TO JSON WEBSERVICE CONSUMER VM CONNECTOR VALIDATION UNTIL SUCCESSFUL
SUB FLOW SET & REMOVE VARIABLE TRANSACTION ID SCATTER GATHER ROUND ROBIN
CONSUME REST WEBSERVICE CRUD OPERATIONS PARSE TEMPLATE OBJECT TO JSON LOAD STATIC RESOURCE
JSON TO XML INVOKE IDEMPOTENT FILTER FOR EACH FLAT TO JSON
FIXWIDTH TO JSON FIRST SUCCESSFUL FILE OPERATIONS EXECUTE ERROR HANDLING
EMAIL FUNCTIONALITY DYNAMIC EVALUATE CUSTOM BUSINESS EVENT CSV TO JSON COPYBOOK TO JSON
CHOICE ASYNC

Widely used Connectors in Mule 3

CMIS JETTY VM CONNECTOR SALESFORCE POP3
JMS TCP/IP WEBSERVICE CONSUMER QUARTZ MONGO DB
FILE CONNECTOR DATABASE CONNECTOR


Widely used Scopes in Mule 3

SUB FLOW REQUEST REPLY PROCESSOR CHAIN FOR EACH CACHE
ASYNC TCP/IP COMPOSITE SOURCE POLL UNTIL SUCCESSFUL
TRANSACTIONAL FLOW

Widely used Components in Mule 3

EXPRESSION CXF SCRIPT RUBY PYTHON
JAVASCRIPT JAVA INVOKE CUSTOM BUSINESS EVENT GROOVY
ECHO LOGGER


Widely used Transformers in Mule 3

MONGO DB XSLT TRANSFORMER REFERENCE SCRIPT RUBY
PYTHON MESSAGE PROPERTIES JAVA TRANSFORMER GZIP COMPRESS/UNCOMPRESS GROOVY
EXPRESSION DOM TO XML STRING VALIDATION COMBINE COLLECTIONS BYTE ARRAY TO STRING
ATTACHMENT TRANSFORMER FILE TO STRING XML TO DOM APPEND STRING JAVASCRIPT
JSON TO JAVA COPYBOOK TO JSON MAP TO JSON JSON TO XML FLATFILE TO JSON
FIXWIDTH TO JSON CSV TO JSON


Widely used Filters in Mule 3

WILDCARD SCHEMA VALIDATION REGEX PAYLOAD OR
NOT MESSAGE PROPERTY MESSAGE IDEMPOTENT FILTER REFERNCE
EXPRESSION EXCEPTION CUSTOM AND


Exception Strategy in Mule 3

REFERENCE EXCEPTION STRATEGY CUSTOM EXCEPTION STRATEGY CHOICE EXCEPTION STRATEGY CATCH EXCEPTION STRATEGY GLOBAL EXCEPTION STRATEGY


Flow Control in Mule 3

CHOICE COLLECTION AGGREGATOR COLLECTION SPLITTER CUSTOM AGGREGATOR FIRST SUCCESSFUL
MESSAGE CHUNK AGGREGATOR MESSAGE CHUNK SPLITTER RESEQUENCER ROUND ROBIN SOAP ROUTER