Package org.axonframework.messaging.core

Class DelegatingMessageStream<DM extends Message,RM extends Message>

java.lang.Object
org.axonframework.messaging.core.DelegatingMessageStream<DM,RM>
Type Parameters:
DM - The type of Message handled by the delegate.
RM - The type of Message handled by this MessageStream.
All Implemented Interfaces:
MessageStream<RM>
Direct Known Subclasses:
CloseCallbackMessageStream
public abstract class DelegatingMessageStream<DM extends Message,RM extends Message> extends Object implements MessageStream<RM>
Abstract implementation of an MessageStream that delegates calls to a given delegate.
Since:
5.0.0
Author:
Allard Buijze

  • Constructor Details

    • DelegatingMessageStream

      public DelegatingMessageStream(@Nonnull MessageStream<DM> delegate)
      Constructs the DelegatingMessageStream with given delegate to receive calls.
      Parameters:
      delegate - The instance to delegate calls to.

  • Method Details

    • setCallback

      public void setCallback(@Nonnull Runnable callback)
      Description copied from interface: MessageStream
      Registers the callback to invoke when entries are available for reading or when the stream completes (either normally or with an error). An invocation of the callback does not in any way guarantee that entries are indeed available, or that the stream has indeed been completed. Implementations may choose to suppress repeated invocations of the callback if no entries have been read in the meantime.

      Any previously registered callback is replaced with the given callback.

      The callback is called on an arbitrary thread, and it should keep work performed on this thread to a minimum as this may interfere with other callbacks handled by the same thread. Any exception thrown by the callback will result in the stream completing with this exception as the error.

      Specified by:
      setCallback in interface MessageStream<DM extends Message>
      Parameters:
      callback - The callback to invoke when entries are available for reading, or the stream completes.

    • error

      public Optional<Throwable> error()
      Description copied from interface: MessageStream
      Indicates whether any error has been reported in this stream. Implementations may choose to not return any error here until all entries that were available for reading before any error occurred have been consumed.
      Specified by:
      error in interface MessageStream<DM extends Message>
      Returns:
      An optional containing the possible error this stream completed with.

    • isCompleted

      public boolean isCompleted()
      Description copied from interface: MessageStream
      Indicates whether this stream has been completed. A completed stream will never return entries from MessageStream.next(), and MessageStream.hasNextAvailable() will always return false. If the stream completed with an error, MessageStream.error() will report so.
      Specified by:
      isCompleted in interface MessageStream<DM extends Message>
      Returns:
      true if the stream completed, otherwise false.

    • hasNextAvailable

      public boolean hasNextAvailable()
      Description copied from interface: MessageStream
      Indicates whether an entry is available for immediate reading. When entries are reported available, there is no guarantee that MessageStream.next() will indeed return an entry. However, besides any concurrent activity on this stream, it is guaranteed that no entries are available for reading when this method returns false.
      Specified by:
      hasNextAvailable in interface MessageStream<DM extends Message>
      Returns:
      true when there are entries available for reading, false otherwise.

    • close

      public void close()
      Description copied from interface: MessageStream
      Closes this stream, freeing any possible resources occupied by the underlying stream. After invocation, some entries may still be available for reading.

      Implementations must always release resources when a stream is completed, either with an error or normally. Therefore, it is only required to close() a stream if the consumer decides to not read until the end.

      Specified by:
      close in interface MessageStream<DM extends Message>

    • delegate

      protected MessageStream<DM> delegate()
      Returns the delegate as provided in the constructor.
      Returns:
      the delegate as provided in the constructor.