Class BaseStatefulBoltExecutor

All Implemented Interfaces:
Serializable, IBolt, IComponent, IRichBolt
Direct Known Subclasses:
CheckpointTupleForwarder, StatefulBoltExecutor

public abstract class BaseStatefulBoltExecutor extends Object implements IRichBolt
Base class that abstracts the common logic for executing bolts in a stateful topology.
See Also:
  • Field Details

  • Constructor Details

    • BaseStatefulBoltExecutor

      public BaseStatefulBoltExecutor()
  • Method Details

    • init

      protected void init(TopologyContext context, OutputCollector collector)
    • execute

      public void execute(Tuple input)
      Description copied from interface: IBolt
      Process a single tuple of input. The Tuple object contains metadata on it about which component/stream/task it came from. The values of the Tuple can be accessed using Tuple#getValue. The IBolt does not have to process the Tuple immediately. It is perfectly fine to hang onto a tuple and process it later (for instance, to do an aggregation or join).

      Tuples should be emitted using the OutputCollector provided through the prepare method. It is required that all input tuples are acked or failed at some point using the OutputCollector. Otherwise, Storm will be unable to determine when tuples coming off the spouts have been completed.

      For the common case of acking an input tuple at the end of the execute method, see IBasicBolt which automates this.

      Specified by:
      execute in interface IBolt
      input - The input tuple to be processed.
    • declareCheckpointStream

      protected void declareCheckpointStream(OutputFieldsDeclarer declarer)
    • handleTuple

      protected abstract void handleTuple(Tuple input)
      Sub-classes can implement the logic for handling the tuple.
      input - the input tuple
    • handleCheckpoint

      protected abstract void handleCheckpoint(Tuple checkpointTuple, CheckPointState.Action action, long txid)
      Sub-classes can implement the logic for handling checkpoint tuple.
      checkpointTuple - the checkpoint tuple
      action - the action (prepare, commit, rollback or initstate)
      txid - the transaction id.