Package org.apache.storm.task

Class OutputCollector

java.lang.Object
org.apache.storm.task.OutputCollector
All Implemented Interfaces:
IErrorReporter, IOutputCollector
Direct Known Subclasses:
BaseStatefulBoltExecutor.AnchoringOutputCollector
public class OutputCollector extends Object implements IOutputCollector
This output collector exposes the API for emitting tuples from an IRichBolt. This is the core API for emitting tuples. For a simpler API, and a more restricted form of stream processing, see IBasicBolt and BasicOutputCollector.

  • Constructor Details

  • Method Details

    • emit

      public List<Integer> emit(String streamId, Tuple anchor, List<Object> tuple)
      Emits a new tuple to a specific stream with a single anchor. The emitted values must be immutable.
      Parameters:
      streamId - the stream to emit to
      anchor - the tuple to anchor to
      tuple - the new output tuple from this bolt
      Returns:
      the list of task ids that this new tuple was sent to

    • emit

      public List<Integer> emit(String streamId, List<Object> tuple)
      Emits a new unanchored tuple to the specified stream. Because it's unanchored, if a failure happens downstream, this new tuple won't affect whether any spout tuples are considered failed or not. The emitted values must be immutable.
      Parameters:
      streamId - the stream to emit to
      tuple - the new output tuple from this bolt
      Returns:
      the list of task ids that this new tuple was sent to

    • emit

      public List<Integer> emit(Collection<Tuple> anchors, List<Object> tuple)
      Emits a new tuple to the default stream anchored on a group of input tuples. The emitted values must be immutable.
      Parameters:
      anchors - the tuples to anchor to
      tuple - the new output tuple from this bolt
      Returns:
      the list of task ids that this new tuple was sent to

    • emit

      public List<Integer> emit(Tuple anchor, List<Object> tuple)
      Emits a new tuple to the default stream anchored on a single tuple. The emitted values must be immutable.
      Parameters:
      anchor - the tuple to anchor to
      tuple - the new output tuple from this bolt
      Returns:
      the list of task ids that this new tuple was sent to

    • emit

      public List<Integer> emit(List<Object> tuple)
      Emits a new unanchored tuple to the default stream. Beacuse it's unanchored, if a failure happens downstream, this new tuple won't affect whether any spout tuples are considered failed or not. The emitted values must be immutable.
      Parameters:
      tuple - the new output tuple from this bolt
      Returns:
      the list of task ids that this new tuple was sent to

    • emit

      public List<Integer> emit(String streamId, Collection<Tuple> anchors, List<Object> tuple)
      Description copied from interface: IOutputCollector
      Returns the task ids that received the tuples.
      Specified by:
      emit in interface IOutputCollector

    • emitDirect

      public void emitDirect(int taskId, String streamId, Tuple anchor, List<Object> tuple)
      Emits a tuple directly to the specified task id on the specified stream. If the target bolt does not subscribe to this bolt using a direct grouping, the tuple will not be sent. If the specified output stream is not declared as direct, or the target bolt subscribes with a non-direct grouping, an error will occur at runtime. The emitted values must be immutable.
      Parameters:
      taskId - the taskId to send the new tuple to
      streamId - the stream to send the tuple on. It must be declared as a direct stream in the topology definition.
      anchor - the tuple to anchor to
      tuple - the new output tuple from this bolt

    • emitDirect

      public void emitDirect(int taskId, String streamId, List<Object> tuple)
      Emits a tuple directly to the specified task id on the specified stream. If the target bolt does not subscribe to this bolt using a direct grouping, the tuple will not be sent. If the specified output stream is not declared as direct, or the target bolt subscribes with a non-direct grouping, an error will occur at runtime. Note that this method does not use anchors, so downstream failures won't affect the failure status of any spout tuples. The emitted values must be immutable.
      Parameters:
      taskId - the taskId to send the new tuple to
      streamId - the stream to send the tuple on. It must be declared as a direct stream in the topology definition.
      tuple - the new output tuple from this bolt

    • emitDirect

      public void emitDirect(int taskId, Collection<Tuple> anchors, List<Object> tuple)
      Emits a tuple directly to the specified task id on the default stream. If the target bolt does not subscribe to this bolt using a direct grouping, the tuple will not be sent. If the specified output stream is not declared as direct, or the target bolt subscribes with a non-direct grouping, an error will occur at runtime. The emitted values must be immutable.

      The default stream must be declared as direct in the topology definition. See OutputDeclarer#declare for how this is done when defining topologies in Java.

      Parameters:
      taskId - the taskId to send the new tuple to
      anchors - the tuples to anchor to
      tuple - the new output tuple from this bolt

    • emitDirect

      public void emitDirect(int taskId, Tuple anchor, List<Object> tuple)
      Emits a tuple directly to the specified task id on the default stream. If the target bolt does not subscribe to this bolt using a direct grouping, the tuple will not be sent. If the specified output stream is not declared as direct, or the target bolt subscribes with a non-direct grouping, an error will occur at runtime. The emitted values must be immutable.

      The default stream must be declared as direct in the topology definition. See OutputDeclarer#declare for how this is done when defining topologies in Java.

      Parameters:
      taskId - the taskId to send the new tuple to
      anchor - the tuple to anchor to
      tuple - the new output tuple from this bolt

    • emitDirect

      public void emitDirect(int taskId, List<Object> tuple)
      Emits a tuple directly to the specified task id on the default stream. If the target bolt does not subscribe to this bolt using a direct grouping, the tuple will not be sent. If the specified output stream is not declared as direct, or the target bolt subscribes with a non-direct grouping, an error will occur at runtime. The emitted values must be immutable.

      The default stream must be declared as direct in the topology definition. See OutputDeclarer#declare for how this is done when defining topologies in Java.<

      Note that this method does not use anchors, so downstream failures won't affect the failure status of any spout tuples.

      Parameters:
      taskId - the taskId to send the new tuple to
      tuple - the new output tuple from this bolt

    • emitDirect

      public void emitDirect(int taskId, String streamId, Collection<Tuple> anchors, List<Object> tuple)
      Specified by:
      emitDirect in interface IOutputCollector

    • ack

      public void ack(Tuple input)
      Specified by:
      ack in interface IOutputCollector

    • fail

      public void fail(Tuple input)
      Specified by:
      fail in interface IOutputCollector

    • resetTimeout

      public void resetTimeout(Tuple input)
      Resets the message timeout for any tuple trees to which the given tuple belongs. The timeout is reset to Config.TOPOLOGY_MESSAGE_TIMEOUT_SECS. Note that this is an expensive operation, and should be used sparingly.
      Specified by:
      resetTimeout in interface IOutputCollector
      Parameters:
      input - the tuple to reset timeout for

    • reportError

      public void reportError(Throwable error)
      Specified by:
      reportError in interface IErrorReporter

    • flush

      public void flush()
      Specified by:
      flush in interface IOutputCollector