How to handle HTTP status code 404 in wso2 EI?

Question

I am calling 2 sequence inside iterator. But if any of the sequence is failing with HTTP status code 404 then control is going to fault sequence and other sequences are not being executed. Is there a way i can handle this issue and my all sequences should run and iterator should be executed as there is no issue in any sequence. I wrote custom error handler sequence to handle 404 status code.

Basically how to handle HTTP status code 404 response and ignore that 404 code. Set some custom error message and continue other sequences in the flow.

Thanks, Vipin

Answer 1

You can use axis2 property HTTP_SC and the SWITCH mediator to handle the HTTP status of the response. Here is a sample API. It has three GET resources, one /exists just returns 200, /test404 emulates call to not existent Uri, and /testnot404 - calls the /exist URI. The message processing in both methods is the same - they use switch mediator to handle HTTP_SC axis2 property.

<api xmlns="http://ws.apache.org/ns/synapse" name="StakeOverflow" context="/so">  <resource methods="GET" uri-template="/exist">  <inSequence>  <respond/>    </inSequence>    </resource>    <resource methods="GET" uri-template="/test404">
      <inSequence>
         <call>
            <endpoint>
               <http method="GET" uri-template="http://localhost:8280/so/notExist"/>
            </endpoint>
         </call>
         <switch source="get-property('axis2', 'HTTP_SC')">
            <case regex="404">
               <payloadFactory media-type="json">
                  <format>{"result":"404"}</format>
                  <args/>
               </payloadFactory>
            </case>
            <default>
               <payloadFactory media-type="json">
                  <format>{"result":"not 404"}</format>
                  <args/>
               </payloadFactory>
            </default>
         </switch>
         <property name="HTTP_SC" value="200" scope="axis2" type="STRING"/>
         <respond/>
      </inSequence>    </resource>
    <resource methods="GET" uri-template="/testnot404">
      <inSequence>
         <call>
            <endpoint>
               <http method="GET" uri-template="http://localhost:8280/so/exist"/>
            </endpoint>
         </call>
         <switch source="get-property('axis2', 'HTTP_SC')">
            <case regex="404">
               <payloadFactory media-type="json">
                  <format>{"result":"404"}</format>
                  <args/>
               </payloadFactory>
            </case>
            <default>
               <payloadFactory media-type="json">
                  <format>{"result":"not 404"}</format>
                  <args/>
               </payloadFactory>
            </default>
         </switch>
         <property name="HTTP_SC" value="200" scope="axis2" type="STRING"/>
         <respond/>
      </inSequence>    </resource> </api>