Mule Exception strategy definition: Invalid content was found starting with element 'choice-exception-strategy'

Question

I'm developing a mule work-flow to insert a record into the database, trying to catch the exception in case if the record is already present and send the HTTP status (409-Conflict) and the back to the client.

<when expression="#[message.inboundProperties['http.method'] == 'POST']"> 
                        <json:json-to-object-transformer returnClass="java.lang.Object" doc:name="JSON to Object" />
                        <set-variable variableName="id" value="#[message.payload.id]" doc:name="Save brandId"/>
                        <json:object-to-json-transformer doc:name="Object to JSON"/>
                        <db:insert config-ref="Postgres" doc:name="Configstore">
                            <db:parameterized-query><![CDATA[INSERT INTO messages("id", "data") VALUES ( #[flowVars['id']], CAST(#[message.payload] as json))]]> </db:parameterized-query>
                        </db:insert>
                        <logger message="REST Response = #[message.payload]" level="INFO" doc:name="LOG Rest Response"></logger>

                         <choice-exception-strategy name="Global_Choice_Exception_Strategy" doc:name="Global Choice Exception Strategy">
                            <catch-exception-strategy doc:name="Catch_Exception_Strategy" when="#[exception.causedBy(org.postgresql.util.PSQLException)]">
                            <set-payload value="The request cannot be processed, the error is #[exception.getExceptionPayload()]"/>
                                <set-property propertyName="http.status" value="404"/> 
                                <http:outbound-endpoint exchange-pattern="request-response" host="localhost" port="8081" method="POST" doc:name="HTTP"/>
                            </catch-exception-strategy>
                         </choice-exception-strategy>  

                    </when>

The start-up is repeatedly failing and the following error reported in the logs.

cvc-complex-type.2.4.a: Invalid content was found starting with element 'choice-exception-strategy'. One of '{"http://www.mulesoft.org/schema/mule/core":abstract-message-processor, "http://www.mulesoft.org/schema/mule/core":abstract-outbound-endpoint, "http://www.mulesoft.org/schema/mule/core":abstract-mixed-content-message-processor}' is expected. at org.apache.xerces.util.ErrorHandlerWrapper.createSAXParseException(Unknown Source) ~[?:?]

This error alternatively reported for both choice-exception-strategy and catch-exception-strategy. Not sure what's invalid here or need to define a custom message-processor or outbound-endpoint. I'm using mule EE-3.8.0

Answer 1

The problem is that you are using an exception strategy within a choice element. The exception strategy must be defined for your whole flow, not single elements (some do allow them though but are rare cases). You can find more on this here and an example here.

HTH