io.netty.handler.codec

类 MessageToMessageCodec<INBOUND_IN,OUTBOUND_IN>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.channel.ChannelDuplexHandler

io.netty.handler.codec.MessageToMessageCodec<INBOUND_IN,OUTBOUND_IN>

所有已实现的接口:

ChannelHandler, ChannelInboundHandler, ChannelOutboundHandler

直接已知子类:

Http2StreamFrameToHttpObjectCodec, HttpContentEncoder, SpdyHttpResponseStreamIdHandler, StompWebSocketProtocolCodec

public abstract class MessageToMessageCodec<INBOUND_IN,OUTBOUND_IN>
extends ChannelDuplexHandler

A Codec for on-the-fly encoding/decoding of message. This can be thought of as a combination of MessageToMessageDecoder and MessageToMessageEncoder. Here is an example of a MessageToMessageCodec which just decode from Integer to Long and encode from Long to Integer.

     public class NumberCodec extends
             MessageToMessageCodec<Integer, Long> {
          @Override
         public Long decode(ChannelHandlerContext ctx, Integer msg, List<Object> out)
                 throws Exception {
             out.add(msg.longValue());
         }

          @Override
         public Integer encode(ChannelHandlerContext ctx, Long msg, List<Object> out)
                 throws Exception {
             out.add(msg.intValue());
         }
     }
 

Be aware that you need to call ReferenceCounted.retain() on messages that are just passed through if they are of type ReferenceCounted. This is needed as the MessageToMessageCodec will call ReferenceCounted.release() on encoded / decoded messages.

嵌套类概要

从接口继承的嵌套类/接口 io.netty.channel.ChannelHandler

ChannelHandler.Sharable

构造器概要

构造器

限定符	构造器和说明
protected	MessageToMessageCodec() Create a new instance which will try to detect the types to decode and encode out of the type parameter of the class.
protected	MessageToMessageCodec(java.lang.Class<? extends INBOUND_IN> inboundMessageType, java.lang.Class<? extends OUTBOUND_IN> outboundMessageType) Create a new instance.

方法概要

限定符和类型	方法和说明
boolean	acceptInboundMessage(java.lang.Object msg) Returns true if and only if the specified message can be decoded by this codec.
boolean	acceptOutboundMessage(java.lang.Object msg) Returns true if and only if the specified message can be encoded by this codec.
void	channelRead(ChannelHandlerContext ctx, java.lang.Object msg) Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline.
protected abstract void	decode(ChannelHandlerContext ctx, INBOUND_IN msg, java.util.List<java.lang.Object> out)
protected abstract void	encode(ChannelHandlerContext ctx, OUTBOUND_IN msg, java.util.List<java.lang.Object> out)
void	write(ChannelHandlerContext ctx, java.lang.Object msg, ChannelPromise promise) Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline.

从类继承的方法 io.netty.channel.ChannelDuplexHandler

bind, close, connect, deregister, disconnect, flush, read

从类继承的方法 io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

从类继承的方法 io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

从类继承的方法 java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

从接口继承的方法 io.netty.channel.ChannelHandler

exceptionCaught, handlerAdded, handlerRemoved

构造器详细资料

MessageToMessageCodec

protected MessageToMessageCodec()

Create a new instance which will try to detect the types to decode and encode out of the type parameter of the class.

MessageToMessageCodec

protected MessageToMessageCodec(java.lang.Class<? extends INBOUND_IN> inboundMessageType,
                                java.lang.Class<? extends OUTBOUND_IN> outboundMessageType)

Create a new instance.

参数:

inboundMessageType - The type of messages to decode

outboundMessageType - The type of messages to encode

方法详细资料

channelRead

public void channelRead(ChannelHandlerContext ctx,
                        java.lang.Object msg)
                 throws java.lang.Exception

从类复制的说明: ChannelInboundHandlerAdapter

Calls ChannelHandlerContext.fireChannelRead(Object) to forward to the next ChannelInboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

channelRead 在接口中 ChannelInboundHandler

覆盖:

channelRead 在类中 ChannelInboundHandlerAdapter

抛出:

java.lang.Exception

write

public void write(ChannelHandlerContext ctx,
                  java.lang.Object msg,
                  ChannelPromise promise)
           throws java.lang.Exception

从类复制的说明: ChannelDuplexHandler

Calls ChannelOutboundInvoker.write(Object, ChannelPromise) to forward to the next ChannelOutboundHandler in the ChannelPipeline. Sub-classes may override this method to change behavior.

指定者:

write 在接口中 ChannelOutboundHandler

覆盖:

write 在类中 ChannelDuplexHandler

参数:

ctx - the ChannelHandlerContext for which the write operation is made

msg - the message to write

promise - the ChannelPromise to notify once the operation completes

抛出:

java.lang.Exception - thrown if an error occurs

acceptInboundMessage

public boolean acceptInboundMessage(java.lang.Object msg)
                             throws java.lang.Exception

Returns true if and only if the specified message can be decoded by this codec.

参数:

msg - the message

抛出:

java.lang.Exception

acceptOutboundMessage

public boolean acceptOutboundMessage(java.lang.Object msg)
                              throws java.lang.Exception

Returns true if and only if the specified message can be encoded by this codec.

参数:

msg - the message

抛出:

java.lang.Exception

encode

protected abstract void encode(ChannelHandlerContext ctx,
                               OUTBOUND_IN msg,
                               java.util.List<java.lang.Object> out)
                        throws java.lang.Exception

抛出:

java.lang.Exception

另请参阅:

MessageToMessageEncoder.encode(ChannelHandlerContext, Object, List)

decode

protected abstract void decode(ChannelHandlerContext ctx,
                               INBOUND_IN msg,
                               java.util.List<java.lang.Object> out)
                        throws java.lang.Exception

抛出:

java.lang.Exception

另请参阅:

MessageToMessageDecoder.decode(ChannelHandlerContext, Object, List)