Package org.apache.storm.spout

Class SpoutOutputCollector

java.lang.Object
org.apache.storm.spout.SpoutOutputCollector
All Implemented Interfaces:
ISpoutOutputCollector, IErrorReporter
public class SpoutOutputCollector extends Object implements ISpoutOutputCollector
This output collector exposes the API for emitting tuples from an IRichSpout. The main difference between this output collector and OutputCollector for IRichBolt is that spouts can tag messages with ids so that they can be acked or failed later on. This is the Spout portion of Storm's API to guarantee that each message is fully processed at least once.

  • Constructor Details

  • Method Details

    • emit

      public List<Integer> emit(String streamId, List<Object> tuple, Object messageId)
      Emits a new tuple to the specified output stream with the given message ID. When Storm detects that this tuple has been fully processed, or has failed to be fully processed, the spout will receive an ack or fail callback respectively with the messageId as long as the messageId was not null. If the messageId was null, Storm will not track the tuple and no callback will be received. Note that Storm's event logging functionality will only work if the messageId is serializable via Kryo or the Serializable interface. The emitted values must be immutable.
      Specified by:
      emit in interface ISpoutOutputCollector
      Returns:
      the list of task ids that this tuple was sent to

    • emit

      public List<Integer> emit(List<Object> tuple, Object messageId)
      Emits a new tuple to the default output stream with the given message ID. When Storm detects that this tuple has been fully processed, or has failed to be fully processed, the spout will receive an ack or fail callback respectively with the messageId as long as the messageId was not null. If the messageId was null, Storm will not track the tuple and no callback will be received. Note that Storm's event logging functionality will only work if the messageId is serializable via Kryo or the Serializable interface. The emitted values must be immutable.
      Returns:
      the list of task ids that this tuple was sent to

    • emit

      public List<Integer> emit(List<Object> tuple)
      Emits a tuple to the default output stream with a null message id. Storm will not track this message so ack and fail will never be called for this tuple. The emitted values must be immutable.

    • emit

      public List<Integer> emit(String streamId, List<Object> tuple)
      Emits a tuple to the specified output stream with a null message id. Storm will not track this message so ack and fail will never be called for this tuple. The emitted values must be immutable.

    • emitDirect

      public void emitDirect(int taskId, String streamId, List<Object> tuple, Object messageId)
      Emits a tuple to the specified task on the specified output stream. This output stream must have been declared as a direct stream, and the specified task must use a direct grouping on this stream to receive the message. Note that Storm's event logging functionality will only work if the messageId is serializable via Kryo or the Serializable interface. The emitted values must be immutable.
      Specified by:
      emitDirect in interface ISpoutOutputCollector

    • emitDirect

      public void emitDirect(int taskId, List<Object> tuple, Object messageId)
      Emits a tuple to the specified task on the default output stream. This output stream must have been declared as a direct stream, and the specified task must use a direct grouping on this stream to receive the message. Note that Storm's event logging functionality will only work if the messageId is serializable via Kryo or the Serializable interface. The emitted values must be immutable.

    • emitDirect

      public void emitDirect(int taskId, String streamId, List<Object> tuple)
      Emits a tuple to the specified task on the specified output stream. This output stream must have been declared as a direct stream, and the specified task must use a direct grouping on this stream to receive the message. The emitted values must be immutable.

      Because no message id is specified, Storm will not track this message so ack and fail will never be called for this tuple.

    • emitDirect

      public void emitDirect(int taskId, List<Object> tuple)
      Emits a tuple to the specified task on the default output stream. This output stream must have been declared as a direct stream, and the specified task must use a direct grouping on this stream to receive the message. The emitted values must be immutable.

      Because no message id is specified, Storm will not track this message so ack and fail will never be called for this tuple.

    • flush

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

    • reportError

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

    • getPendingCount

      public long getPendingCount()
      Specified by:
      getPendingCount in interface ISpoutOutputCollector