Vert.x data

1. Buffer

Vert.x Buffer is just a wrapper around netty Buffer. I don't see it providing any additional functionality yet. Have to make sure why it exists.

Update: the getBuffer(int start, int end) and similar copy slicing methods are not directly supported by netty Buffer.

2. Message

The interface of a Message is simple:

public abstract class Message<T>  {
  /**
   * The body of the message
   */
  public T body;

  /**
   * The reply address (if any)
   */
  public String replyAddress;

  /**
   * Same as {@code reply(T message)} but with an empty body
   */
  public void reply() {
    reply(null);
  }

  /**
   * Reply to this message. If the message was sent specifying a reply handler, that handler will be
   * called when it has received a reply. If the message wasn't sent specifying a receipt handler
   * this method does nothing.
   */
  public void reply(T message) {
    reply(message, null);
  }

  /**
   * The same as {@code reply(T message)} but you can specify handler for the reply - i.e.
   * to receive the reply to the reply.
   */
  public abstract void reply(T message, Handler<Message<T>> replyHandler);

}

There is :

1. The body of the message, usually a JsonObject or other elementary data types like Integer.

2. The replyAddress, for replying messages

3. A bunch of reply methods

Question: Is there a simpler message type that has no reply? It will save some memory

3. JsonObject and JsonArray

JsonObject is a wrapper of Map<String, Object> that adds getXXX() and putXXX() methods for convenience.

JsonArray is a wrapper of List<Object>

They are designed for interface integrity and user efficiency.