Mule exception strategies - Catch exception strategy
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The document discusses exception handling strategies in Mule. It defines an exception as an event that disrupts normal program flow. Mule has different exception strategies, including catch exception strategy. The catch exception strategy commits transactions and consumes messages when exceptions are thrown. The document provides an XML code example of configuring a flow with a catch exception strategy that catches a divide by zero exception and routes it to a Java class for handling.
Mule exception strategies - Catch exception strategy
- 2. INDEX What is exception? Mule Exception Strategy Catch Exception Strategy Configure Catch Exception Strategy Result
- 3. What is a exception? An exception is an event, which occurs during the execution of a program, that disrupts the normal flow of the program's instructions. When an error occurs within a method, the method creates an object and hands it off to the runtime system.
- 4. Mule Exception Strategy Mule ESB 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 to configure various exception strategies. There are five of them – Default Exception strategy Catch exception strategy Roll-back exception strategy Reference exception strategy Choice exception strategy In this presentation we’ll talk about Catch exception strategy.
- 5. Catch Exception Strategy When a message throws an exception, the catch exception strategy always commits the transaction and consumes the message. So it basically work like try/catch from Java.
- 6. Configure Catch Exception Strategy (Cont.)Following is the XML code for the flow: <?xml version="1.0" encoding="UTF-8"?> <mule xmlns:jersey="http://www.mulesoft.org/schema/mule/jersey" xmlns:quartz="http://www.mulesoft.org/schema/mule/quartz" 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/quartz http://www.mulesoft.org/schema/mule/quartz/current/mule-quartz.xsd http://www.mulesoft.org/schema/mule/jersey http://www.mulesoft.org/schema/mule/jersey/current/mule-jersey.xsd"> <http:listener-config name="HTTP_Listener_Configuration" host="0.0.0.0" port="8080" doc:name="HTTP Listener Configuration"/> <flow name="http_illustrationFlow"> <http:listener config-ref="HTTP_Listener_Configuration" path="/" doc:name="HTTP"/> <expression-filter expression="#[payload == 999999999/0" doc:name="Expression"/> <catch-exception-strategy doc:name="Catch Exception Strategy"> <component class="http_illustration.ErrorHandler" doc:name="Java"/> </catch-exception-strategy> </flow> </mule>
- 7. Configure Catch Exception Strategy The diagrammatic view will be – Here I’ve created a flow which listens at 8080 port and then there is an expression with wrong syntax which will throw an exception and then the flow will transfer to Java class inside Catch exception strategy where message “Catch exception strategy illustration.” will be returned to calling entity.
- 8. Result When there will be a call to this flow from browser, the message returned from java class will there on browser.