rabbitmq-global-error-handler

The main goal of this project is to show how to configure global error handling for exceptions occurred during receiving them on the listeners (getting from the queue).

Reference: https://github.com/spring-projects/spring-amqp-samples/blob/master/spring-rabbit-global-errorhandler/src/main/java/org/springframework/amqp/samples/errorhandler/Application.java

use case

On the rabbitmq queue appears a message that cannot be parsed to the dtos over the appropriate listener (for example - has completely different structure or some fields has other type or it could have no structure at all - because AMQP propagate byte-body messages) we want to log it.

solution

1. GlobalErrorConfig: @Configuration class that produces org.springframework.util.ErrorHandler bean.
2. RejectingErrorHandler: extension of org.springframework.amqp.rabbit.listener.ConditionalRejectingErrorHandler.DefaultExceptionStrategy

   • in isFatal we perform logging action (only in case of ListenerExecutionFailedException)

     Remark: only if isFatal returns true a message is removed from a queue

   • in isUserCauseFatal we define all exception as fatal

remarks

ConditionalRejectingErrorHandler.DefaultExceptionStrategy:

• isFatal:

  @Override
  public boolean isFatal(Throwable t) {
  	Throwable cause = t.getCause();
  	while (cause instanceof MessagingException
  			&& !(cause instanceof
  					org.springframework.messaging.converter.MessageConversionException)
  			&& !(cause instanceof MethodArgumentResolutionException)) {
  		cause = cause.getCause();
  	}
  	if (t instanceof ListenerExecutionFailedException && isCauseFatal(cause)) {
  		if (this.logger.isWarnEnabled()) {
  			this.logger.warn(
  					"Fatal message conversion error; message rejected; "
  					+ "it will be dropped or routed to a dead letter exchange, if so configured: "
  					+ ((ListenerExecutionFailedException) t).getFailedMessage());
  		}
  		return true;
  	}
  	return false;
  }   
  

• isCauseFatal

  private boolean isCauseFatal(Throwable cause) {
  			return cause instanceof MessageConversionException
  					|| cause instanceof org.springframework.messaging.converter.MessageConversionException
  					|| cause instanceof MethodArgumentResolutionException
  					|| cause instanceof NoSuchMethodException
  					|| cause instanceof ClassCastException
  					|| isUserCauseFatal(cause);
  		} 
  

• isUserCauseFatal

  protected boolean isUserCauseFatal(Throwable cause) {
  			return false;
  		}