Interface IMessageFilter<M>

All Known Implementing Classes:
ElFilter, Filters.RejectSubtypes, Filters.SubtypesOnly
public interface IMessageFilter<M>
Message filters can be used to control what messages are delivered to a specific message handler. Filters are attached to message handler using the @Handler annotation. If a message handler specifies filters, the filters accepts(...) method will be checked before the actual handler is invoked. The handler will be invoked only if each filter accepted the message. Example: 

@Listener
@Filters(Urlfilter.class)
public void someHandler(String message){...}

class Urlfilter implements IMessageFilter{
    public boolean accepts(String message, SubscriptionContext context){
        return message.startsWith("http");
    }
}

bus.post("http://www.infoq.com"); // will be delivered
bus.post("www.stackoverflow.com"); // will not be delivered
NOTE: A message filter must provide a no-arg constructor!!!

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    accepts(M message, SubscriptionContext context)
    Check whether the message matches some criteria

  • Method Details

    • accepts

      boolean accepts(M message, SubscriptionContext context)
      Check whether the message matches some criteria
      Parameters:
      message - The message to be handled by the handler
      context - The context object containing a description of the message handler and the bus environment
      Returns:
      true: if the message matches the criteria and should be delivered to the handler false: otherwise