mongo-config.xml

<mongo:config name="mongoDb" database="testDb" host="localhost" port="27017" />
 
<flow name="setNullComponent">
	<expression-transformer expression="org.mule.transport.NullPayload.getInstance()" evaluator="groovy"></expression-transformer>
</flow>
 
<flow name="getTestCollectionFlow">
	<vm:inbound-endpoint path="getTestCollection" exchange-pattern="request-response" />
 
	<!-- workaround for mongo throwing exception when it does not find an entry in the db -->
	<first-successful>
		<!-- try query -->
		<mongo:find-one-object collection="testCollection" config-ref="mongoDb" query="#[string:{ &quot;id&quot; : #[bean:id] } ]" />
		<!-- if previous call throws exception, set the payload to NullPayload -->
		<flow-ref name="setNullComponent" />
	</first-successful>
 
</flow>