Custom Event Executor

Writing a Custom Event Executor¶

WSO2 Open Banking Accelerator contains an event executor that processes events taken from an event queue asynchronously. Relevant events are added to the event queue by WSO2 Open Banking Accelerator depending on the event triggering scenario. Currently, all the consent state-changing events are added to the event queue.

You can implement the interface provided in WSO2 Open Banking Accelerator and process the events according to your open banking requirements:

• To implement a custom Event Executor, extend the following class:

com.wso2.openbanking.accelerator.common.event.executor.OBEventExecutor

Given below is a brief explanation of the methods you need to implement.

processEvent method¶

This method processes the events polled from the event queue. Given below is the method signature:

public void processEvent(OBEvent obEvent)

Input parameters

• OBEvent obEvent - contains an OBEvent object with event related details.

    private String eventType;
    private Map<String, Object> eventData;

    public OBEvent(String eventType, Map<String, Object> eventData) {

       this.eventType = eventType;
       this.eventData = eventData;
    }

    public String getEventType() {

       return eventType;
    }

    public Map<String, Object> getEventData() {

       return eventData;
    }

Use the following values to perform business logic:

For example:

• Implement the OBEventExecutor class and override the processEvent method in your class as follows:

   @Override
   public void processEvent(OBEvent obEvent) {

      Map<String, Object> eventData = obEvent.getEventData();

      if (Boolean.parseBoolean(OpenBankingCDSConfigParser.getInstance().getConfiguration()
              .get(CDSConsentExtensionConstants.ENABLE_RECIPIENT_CONSENT_REVOCATION).toString())
              && ConsentCoreServiceConstants.CONSENT_REVOKE_FROM_DASHBOARD_REASON.equals(eventData.get(REASON))
              && REVOKED_STATE.equalsIgnoreCase(obEvent.getEventType())) {

          // call DR's arrangement revocation endpoint
          try {
              if (eventData.get(CLIENT_ID) != null && eventData.get(CONSENT_ID) != null) {
                  sendArrangementRevocationRequestToADR(eventData.get(CLIENT_ID).toString(),
                          eventData.get(CONSENT_ID).toString(), OpenBankingCDSConfigParser.getInstance()
                                  .getConfiguration().get(CDSConsentExtensionConstants.DATA_HOLDER_ID).toString());
              } else {
                  log.error("Consent ID/Client ID cannot be null");
              }
          } catch (OpenBankingException e) {
              log.error("Something went wrong when sending the arrangement revocation request to ADR", e);
          }
      }

   }

   protected void sendArrangementRevocationRequestToADR(String clientId, String consentId, String dataHolderId)
          throws OpenBankingException {

       // implementation logic
   }

Configuring a Custom Event Executor¶

1. Once implemented, build a JAR file for your Custom Event Executor and place it in either or both <IS_HOME>/repository/components/lib directory and <APIM_HOME>/repository/components/lib directory based on your requirement.
2. Open the <IS_HOME>/repository/conf/deployment.toml file if you have placed the JAR file in the <IS_HOME>/repository/components/lib directory in step 1.

3. Find the [open_banking.event] tag and configure the queue size, the number of worker threads, and the event executor using the Fully Qualified Name (FQN) of your custom event executor class. For example:

   [open_banking.event]
   queue_size=32768
   worker_thread_count=10
   event_executor="com.wso2.openbanking.accelerator.common.event.executor.DefaultOBEventExecutor"
   

4. Save the above configurations and restart the Identity Server.

5. Repeat steps 2 and 3 for API Manager using the <APIM_HOME>/repository/conf/deployment.toml file if you have placed the JAR file in the <APIM_HOME>/repository/components/lib directory in step 1.
6. Restart the API Manager server.