Package org.apache.camel.spi

Interface PollingConsumerPollStrategy

public interface PollingConsumerPollStrategy
Strategy for a PollingConsumer when polling an Endpoint.

This pluggable strategy allows to plugin different implementations what to do, most noticeable what to do in case the polling goes wrong. This can be handled in the rollback method.

  • Method Summary

    Modifier and Type
    Method
    Description
    boolean
    begin(Consumer consumer, Endpoint endpoint)
    Called when poll is about to begin
    void
    commit(Consumer consumer, Endpoint endpoint, int polledMessages)
    Called when poll is completed successfully
    boolean
    rollback(Consumer consumer, Endpoint endpoint, int retryCounter, Exception cause)
    Called when poll failed

  • Method Details

    • begin

      boolean begin(Consumer consumer, Endpoint endpoint)
      Called when poll is about to begin
      Parameters:
      consumer - the consumer
      endpoint - the endpoint being consumed
      Returns:
      true to begin polling, or false to skip polling this time.

    • commit

      void commit(Consumer consumer, Endpoint endpoint, int polledMessages)
      Called when poll is completed successfully
      Parameters:
      consumer - the consumer
      endpoint - the endpoint being consumed
      polledMessages - number of messages polled, will be 0 if no message was polled at all.

    • rollback

      boolean rollback(Consumer consumer, Endpoint endpoint, int retryCounter, Exception cause) throws Exception
      Called when poll failed
      Parameters:
      consumer - the consumer
      endpoint - the endpoint being consumed
      retryCounter - current retry attempt, starting from 0.
      cause - the caused exception
      Returns:
      whether to retry immediately or not. Return false to ignore the problem, true to try immediately again
      Throws:
      Exception - can be used to rethrow the caused exception. Notice that thrown an exception will terminate the scheduler and thus Camel will not trigger again. So if you want to let the scheduler to continue to run then do not throw any exception from this method.