ChannelInitializers.java 文件源码

/**
 * Returns a new channel initializer suited to encode and decode a protocol
 * buffer message.
 * <p/>
 * <p>Message sizes over 10 MB are not supported.</p>
 * <p/>
 * <p>The handler will be executed on the I/O thread. Blocking operations
 * should be executed in their own thread.</p>
 *
 * @param defaultInstance an instance of the message to handle
 * @param handler the handler implementing the application logic
 * @param <M> the type of the support protocol buffer message
 */
public static final <M extends Message> ChannelInitializer<Channel> protoBuf(
    final M defaultInstance, final SimpleChannelInboundHandler<M> handler) {
  return new ChannelInitializer<Channel>() {

    @Override
    protected void initChannel(Channel channel) throws Exception {
      channel.pipeline().addLast("frameDecoder",
          new LengthFieldBasedFrameDecoder(10 * 1024 * 1024, 0, 4, 0, 4));
      channel.pipeline().addLast("protobufDecoder",
          new ProtobufDecoder(defaultInstance));
      channel.pipeline().addLast("frameEncoder", new LengthFieldPrepender(4));
      channel.pipeline().addLast("protobufEncoder", new ProtobufEncoder());
      channel.pipeline().addLast("applicationHandler", handler);
    }
  };
}