io.netty.handler.codec

类 MessageToMessageEncoder<I>

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOutboundHandlerAdapter

io.netty.handler.codec.MessageToMessageEncoder<I>

所有已实现的接口:

ChannelHandler, ChannelOutboundHandler

直接已知子类:

AbstractMemcacheObjectEncoder, Base64Encoder, ByteArrayEncoder, DatagramDnsQueryEncoder, DatagramDnsResponseEncoder, DatagramPacketEncoder, HttpObjectEncoder, LengthFieldPrepender, LineEncoder, MqttEncoder, ProtobufEncoder, ProtobufEncoderNano, RedisEncoder, SctpOutboundByteStreamHandler, SmtpRequestEncoder, SpdyHttpEncoder, StompSubframeEncoder, StringEncoder, TcpDnsResponseEncoder, WebSocket00FrameEncoder, WebSocket08FrameEncoder, WebSocketExtensionEncoder

public abstract class MessageToMessageEncoder<I>
extends ChannelOutboundHandlerAdapter

ChannelOutboundHandlerAdapter which encodes from one message to an other message For example here is an implementation which decodes an Integer to an String.

     public class IntegerToStringEncoder extends
             MessageToMessageEncoder<Integer> {

          @Override
         public void encode(ChannelHandlerContext ctx, Integer message, List<Object> out)
                 throws Exception {
             out.add(message.toString());
         }
     }
 

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 MessageToMessageEncoder will call ReferenceCounted.release() on encoded 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	MessageToMessageEncoder() Create a new instance which will try to detect the types to match out of the type parameter of the class.
protected	MessageToMessageEncoder(java.lang.Class<? extends I> outboundMessageType) Create a new instance

方法概要

限定符和类型	方法和说明
boolean	acceptOutboundMessage(java.lang.Object msg) Returns true if the given message should be handled.
protected abstract void	encode(ChannelHandlerContext ctx, I msg, java.util.List<java.lang.Object> out) Encode from one message to an other.
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.ChannelOutboundHandlerAdapter

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

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

ensureNotSharable, exceptionCaught, 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

MessageToMessageEncoder

protected MessageToMessageEncoder()

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

MessageToMessageEncoder

protected MessageToMessageEncoder(java.lang.Class<? extends I> outboundMessageType)

Create a new instance

参数:

outboundMessageType - The type of messages to match and so encode

方法详细资料

acceptOutboundMessage

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

Returns true if the given message should be handled. If false it will be passed to the next ChannelOutboundHandler in the ChannelPipeline.

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: ChannelOutboundHandlerAdapter

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 ChannelOutboundHandlerAdapter

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

encode

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

Encode from one message to an other. This method will be called for each written message that can be handled by this encoder.

参数:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to

msg - the message to encode to an other one

out - the List into which the encoded msg should be added needs to do some kind of aggregation

抛出:

java.lang.Exception - is thrown if an error occurs