[ WSO2 Api Manager 4.1 / Custom Handlers] - wso2

Question

I have developped a custom handler for my apim platform(4.1) where I call a custom class mediator in order to log MessageContext infos into a separated log file as shown below :
public void logUserRequest(MessageContext messageContext) {
Map headers = service.getTransportHeaders(messageContext);
String userId = (String) messageContext.getProperty(APIMgtGatewayConstants.USER_ID);
String api = (String) messageContext.getProperty(APIMgtGatewayConstants.API);
String apiKeyType = (String) messageContext.getProperty(AM_KEY_TYPE);
String appliName = (String) messageContext.getProperty(APIMgtGatewayConstants.APPLICATION_NAME);
String method = (String) messageContext.getProperty(APIMgtGatewayConstants.HTTP_METHOD);
String organisation = (String) messageContext.getProperty(APIMgtGatewayConstants.APPLICATION_NAME);
String version = (String) messageContext.getProperty(APIMgtGatewayConstants.VERSION);
successCallLog.info(userId + "|" + organisation + "|" + apiKeyType + "|" + method + "|" + api + "|" + version + "|" + appliName );
}
It works fine when the log mediator is called inside the handleResponse() method of my handler , but the problem with that is that I don't log the exact time of the request and it is used in another flow to calculate other statistics .
06-10-2022 10:49:00,072|admin#carbon.super|test|PRODUCTION|GET|PizzaShackAPI|1.0.0|test
in the other hand, when I call the log mediator inside the handleRequest() method of my handler , I get null values of the MessageContext properties I'm trying to log :
06-10-2022 10:46:34,311|null|null|null|null|null|null|null|null
PS:
I didn't have this problem using the same handler and mediator in apim version 3.2 .
Am I missing something ? or Did something change between the 2 versions ?

Answer 1

As #DushaniW explained in his comment, the MessageContext properties were not set at the moment my mediator was trying to log them , since the handler calling the mediator was engaged before the APIAuthenticationHandler, which explains null values.
I was able to correct the issue by making sure the default handler APIAuthenticationHandler is called before my custom handler.
I have updated my configuration in velocity_template.xml to engage my custom handler after the foreach loop that engage the default handlers (if my understanding is correct) .
Error :
<handlers xmlns="http://ws.apache.org/ns/synapse">
<!-- ############## CUSTOM : handler X-Correlation-ID ############### -->
<handler class="fr.XX.XX.XX.XX.handler.CustomAPIAuthenticationXCorrelationIDHandler"/>
<!-- ############## CUSTOM : handler X-Correlation-ID ############### -->
<!-- ############## Default handlers ############### -->
#foreach($handler in $handlers)
<handler xmlns="http://ws.apache.org/ns/synapse" class="$handler.className">
#if($handler.hasProperties())
#set ($map = $handler.getProperties() )
#foreach($property in $map.entrySet())
<property name="$!property.key" value="$!property.value"/>
#end
#end
</handler>
#end
Correction :
<handlers xmlns="http://ws.apache.org/ns/synapse">
<!-- ############## Default handlers ############### -->
#foreach($handler in $handlers)
<handler xmlns="http://ws.apache.org/ns/synapse" class="$handler.className">
#if($handler.hasProperties())
#set ($map = $handler.getProperties() )
#foreach($property in $map.entrySet())
<property name="$!property.key" value="$!property.value"/>
#end
#end
</handler>
#end
<!-- ############## CUSTOM : handler X-Correlation-ID ############### -->
<handler class="fr.XX.XX.XX.XX.handler.CustomAPIAuthenticationXCorrelationIDHandler"/>
<!-- ############## CUSTOM : handler X-Correlation-ID ############### -->