How to use

CommandCallbackWrapper

in

org.axonframework.commandhandling.distributed

/**
 * Removes all callbacks for a given channel. Registered callbacks will receive a failure response containing a
 * {@link CommandBusConnectorCommunicationException}.
 *
 * @param channelId the channel identifier
 */
public void cancelCallbacks(A channelId) {
  Iterator<CommandCallbackWrapper> callbacks = this.callbacks.values().iterator();
  while (callbacks.hasNext()) {
    CommandCallbackWrapper wrapper = callbacks.next();
    if (wrapper.getChannelIdentifier().equals(channelId)) {
      wrapper.reportResult(asCommandResultMessage(new CommandBusConnectorCommunicationException(
          String.format("Connection error while waiting for a response on command %s",
                 wrapper.getMessage().getCommandName()))));
      callbacks.remove();
    }
  }
}

/**
 * Invokes {@link CommandCallback#onResult(CommandMessage, CommandResultMessage)} with given {@code result} on
 * the wrapped callback.
 *
 * @param result the result of the command
 */
public void reportResult(CommandResultMessage<R> result) {
  onResult(getMessage(), result);
}

/**
 * Removes all callbacks for a given channel. Registered callbacks will receive a failure response containing a
 * {@link CommandBusConnectorCommunicationException}.
 *
 * @param channelId the channel identifier
 */
public void cancelCallbacks(A channelId) {
  Iterator<CommandCallbackWrapper> callbacks = this.callbacks.values().iterator();
  while (callbacks.hasNext()) {
    CommandCallbackWrapper wrapper = callbacks.next();
    if (wrapper.getChannelIdentifier().equals(channelId)) {
      wrapper.fail(new CommandBusConnectorCommunicationException(
          String.format("Connection error while waiting for a response on command %s",
                 wrapper.getMessage().getCommandName())));
      callbacks.remove();
    }
  }
}

/**
 * Invokes {@link CommandCallback#onSuccess(CommandMessage, Object)} with given {@code result} on the wrapped
 * callback.
 *
 * @param result the result of the command
 */
public void success(R result) {
  onSuccess(getMessage(), result);
}

/**
 * Invokes {@link CommandCallback#onFailure(CommandMessage, Throwable)} with given exception on the wrapped
 * callback.
 *
 * @param e cause for the failure
 */
public void fail(Throwable e) {
  onFailure(getMessage(), e);
}

/**
 * Stores a callback
 *
 * @param callbackId             The id to store the callback with
 * @param commandCallbackWrapper The CommandCallbackWrapper to store
 * @param <E>                    The type of the remote endpoint identifier
 * @param <C>                    The type of the command
 * @param <R>                    The type of the result
 */
public <E, C, R> void store(String callbackId, CommandCallbackWrapper<E, C, R> commandCallbackWrapper) {
  CommandCallbackWrapper previous;
  if ((previous = callbacks.put(callbackId, commandCallbackWrapper)) != null) {
    //a previous callback with the same command ID was already found, we will cancel the callback as the command
    //is likely to be retried, so the previous one likely failed
    previous.reportResult(asCommandResultMessage(new CommandBusConnectorCommunicationException(
        "Command-callback cancelled, a new command with the same ID is entered into the command bus")));
  }
}

private void processReplyMessage(JGroupsReplyMessage message) {
  CommandCallbackWrapper<Object, Object, Object> callbackWrapper =
      callbackRepository.fetchAndRemove(message.getCommandIdentifier());
  if (callbackWrapper == null) {
    logger.warn(
        "Received a callback for a message that has either already received a callback, or which was not " +
            "sent through this node. Ignoring.");
  } else {
    if (message.isSuccess()) {
      callbackWrapper.success(message.getReturnValue(serializer));
    } else {
      Throwable exception = getOrDefault(message.getError(serializer), new IllegalStateException(
          format("Unknown execution failure for command [%s]", message.getCommandIdentifier())));
      callbackWrapper.fail(exception);
    }
  }
}

@Override
public <C, R> void send(Member destination, CommandMessage<C> command,
            CommandCallback<? super C, R> callback) throws Exception {
  callbackRepository.store(command.getIdentifier(), new CommandCallbackWrapper<>(destination, command, callback));
  channel.send(resolveAddress(destination), new JGroupsDispatchMessage(command, serializer, true));
}

/**
 * Stores a callback
 *
 * @param callbackId             The id to store the callback with
 * @param commandCallbackWrapper The CommandCallbackWrapper to store
 * @param <E>                    The type of the remote endpoint identifier
 * @param <C>                    The type of the command
 * @param <R>                    The type of the result
 */
public <E, C, R> void store(String callbackId, CommandCallbackWrapper<E, C, R> commandCallbackWrapper) {
  CommandCallbackWrapper previous;
  if ((previous = callbacks.put(callbackId, commandCallbackWrapper)) != null) {
    //a previous callback with the same command ID was already found, we will cancel the callback as the command
    //is likely to be retried, so the previous one likely failed
    previous.fail(new CommandBusConnectorCommunicationException(
        "Command-callback cancelled, a new command with the same ID is entered into the command bus"));
  }
}

/**
 * Stores a callback
 *
 * @param callbackId             The id to store the callback with
 * @param commandCallbackWrapper The CommandCallbackWrapper to store
 * @param <E>                    The type of the remote endpoint identifier
 * @param <C>                    The type of the command
 * @param <R>                    The type of the result
 */
public <E, C, R> void store(String callbackId, CommandCallbackWrapper<E, C, R> commandCallbackWrapper) {
  CommandCallbackWrapper previous;
  if ((previous = callbacks.put(callbackId, commandCallbackWrapper)) != null) {
    //a previous callback with the same command ID was already found, we will cancel the callback as the command
    //is likely to be retried, so the previous one likely failed
    previous.reportResult(asCommandResultMessage(new CommandBusConnectorCommunicationException(
        "Command-callback cancelled, a new command with the same ID is entered into the command bus")));
  }
}

@Override
public <C, R> void send(Member destination,
            CommandMessage<C> command,
            CommandCallback<? super C, R> callback) throws Exception {
  callbackRepository.store(command.getIdentifier(), new CommandCallbackWrapper<>(destination, command, callback));
  channel.send(resolveAddress(destination), new JGroupsDispatchMessage(command, serializer, true));
}

/**
 * Removes all callbacks for a given channel. Registered callbacks will receive a failure response containing a
 * {@link CommandBusConnectorCommunicationException}.
 *
 * @param channelId the channel identifier
 */
public void cancelCallbacks(A channelId) {
  Iterator<CommandCallbackWrapper> callbacks = this.callbacks.values().iterator();
  while (callbacks.hasNext()) {
    CommandCallbackWrapper wrapper = callbacks.next();
    if (wrapper.getChannelIdentifier().equals(channelId)) {
      wrapper.reportResult(asCommandResultMessage(new CommandBusConnectorCommunicationException(
          String.format("Connection error while waiting for a response on command %s",
                 wrapper.getMessage().getCommandName()))));
      callbacks.remove();
    }
  }
}

/**
 * Invokes {@link CommandCallback#onResult(CommandMessage, CommandResultMessage)} with given {@code result} on
 * the wrapped callback.
 *
 * @param result the result of the command
 */
public void reportResult(CommandResultMessage<R> result) {
  onResult(getMessage(), result);
}

private void processReplyMessage(JGroupsReplyMessage message) {
  CommandCallbackWrapper callbackWrapper = callbackRepository.fetchAndRemove(message.getCommandIdentifier());
  if (callbackWrapper == null) {
    logger.warn("Received a callback for a message that has either already received a callback, "
              + "or which was not sent through this node. Ignoring.");
  } else {
    //noinspection unchecked
    callbackWrapper.reportResult(message.getCommandResultMessage(serializer));
  }
}