Module io.netty5.codec

Package io.netty5.handler.codec

Class MessageToMessageDecoder<I>

java.lang.Object

io.netty5.channel.ChannelHandlerAdapter

io.netty5.handler.codec.MessageToMessageDecoder<I>

All Implemented Interfaces:

ChannelHandler

Direct Known Subclasses:

Base64Decoder, ByteArrayDecoder, DatagramDnsQueryDecoder, DatagramDnsResponseDecoder, DatagramPacketDecoder, HttpContentDecoder, MessageAggregator, StringDecoder, WebSocketClientProtocolHandler, WebSocketExtensionDecoder, WebSocketServerProtocolHandler

public abstract class MessageToMessageDecoder<I>
extends ChannelHandlerAdapter

ChannelHandler which decodes from one message to another message. For example here is an implementation which decodes a String to an Integer which represent the length of the String.

{@code
     public class StringToIntegerDecoder extends
             MessageToMessageDecoder {

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	MessageToMessageDecoder()	Create a new instance which will try to detect the types to match out of the type parameter of the class.
protected	MessageToMessageDecoder(Class<? extends I> inboundMessageType)	Create a new instance

Method Summary

Modifier and Type	Method	Description
boolean	acceptInboundMessage(Object msg)	Returns true if the given message should be handled.
void	channelRead(ChannelHandlerContext ctx, Object msg)	Invoked when the current Channel has read a message from the peer.
protected void	decode(ChannelHandlerContext ctx, I msg)	Decode from one message to another.
protected void	decodeAndClose(ChannelHandlerContext ctx, I msg)	Decode from one message to another.

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty5.channel.ChannelHandler

bind, channelActive, channelExceptionCaught, channelInactive, channelInboundEvent, channelReadComplete, channelRegistered, channelShutdown, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, flush, handlerAdded, handlerRemoved, isSharable, pendingOutboundBytes, read, register, sendOutboundEvent, shutdown, write

Constructor Detail

MessageToMessageDecoder

protected MessageToMessageDecoder()

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

MessageToMessageDecoder

protected MessageToMessageDecoder(Class<? extends I> inboundMessageType)

Create a new instance

Parameters:

inboundMessageType - The type of messages to match and so decode

Method Detail

acceptInboundMessage

public boolean acceptInboundMessage(Object msg)
                             throws Exception

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

Throws:

Exception

channelRead

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

Description copied from interface: ChannelHandler

Invoked when the current Channel has read a message from the peer.

Throws:

Exception

decode

protected void decode(ChannelHandlerContext ctx,
                      I msg)
               throws Exception

Decode from one message to another. This method will be called for each written message that can be handled by this decoder.

The message will be disposed of after this call.

Subclasses that wish to sometimes pass messages through, should instead override the decodeAndClose(ChannelHandlerContext, Object) method.

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

msg - the message to decode to another one

Throws:

Exception - is thrown if an error occurs

decodeAndClose

protected void decodeAndClose(ChannelHandlerContext ctx,
                              I msg)
                       throws Exception

Decode from one message to another. This method will be called for each written message that can be handled by this decoder.

The message will not be automatically disposed of after this call. Instead, the responsibility of ensuring that messages are disposed of falls upon the implementor of this method.

Subclasses that wish to have incoming messages automatically disposed of should instead override the decodeAndClose(ChannelHandlerContext, Object) method.

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

msg - the message to decode to another one

Throws:

Exception - is thrown if an error occurs