Interface MessageCodec<S,R>

Type Parameters:
S - the type of the message being sent
R - the type of the message being received.
All Known Implementing Classes:
ServiceExceptionMessageCodec
public interface MessageCodec<S,R>
A message codec allows a custom message type to be marshalled across the event bus.

Usually the event bus only allows a certain set of message types to be sent across the event bus, including primitive types, boxed primitive types, byte[], JsonObject, JsonArray, Buffer.

By specifying a message codec you can pass any other type across the event bus, e.g. POJOs.

With a message codec the type sent does not have to be the same as the type received, e.g. you could send a Buffer and have it be received as a JsonObject.

Instances of this class must be thread-safe as they may be used concurrently by different threads.

Author:
Tim Fox

  • Method Summary

    Modifier and Type
    Method
    Description
    R
    decodeFromWire(int pos, Buffer buffer)
    Called by Vert.x when a message is decoded from the wire.
    void
    encodeToWire(Buffer buffer, S s)
    Called by Vert.x when marshalling a message to the wire.
    String
    name()
    The codec name.
    byte
    systemCodecID()
    Used to identify system codecs.
    R
    transform(S s)
    If a message is sent locally across the event bus, this method is called to transform the message from the sent type S to the received type R

  • Method Details

    • encodeToWire

      void encodeToWire(Buffer buffer, S s)
      Called by Vert.x when marshalling a message to the wire.
      Parameters:
      buffer - the message should be written into this buffer
      s - the message that is being sent

    • decodeFromWire

      R decodeFromWire(int pos, Buffer buffer)
      Called by Vert.x when a message is decoded from the wire.
      Parameters:
      pos - the position in the buffer where the message should be read from.
      buffer - the buffer to read the message from
      Returns:
      the read message

    • transform

      R transform(S s)
      If a message is sent locally across the event bus, this method is called to transform the message from the sent type S to the received type R
      Parameters:
      s - the sent message
      Returns:
      the transformed message

    • name

      String name()
      The codec name. Each codec must have a unique name. This is used to identify a codec when sending a message and for unregistering codecs.
      Returns:
      the name

    • systemCodecID

      byte systemCodecID()
      Used to identify system codecs. Should always return -1 for a user codec.
      Returns:
      -1 for a user codec.