Module io.netty5.codec

Package io.netty5.handler.codec

Class MessageToMessageEncoder<I>

java.lang.Object

io.netty5.channel.ChannelHandlerAdapter

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

All Implemented Interfaces:

ChannelHandler

Direct Known Subclasses:

Base64Encoder, ByteArrayEncoder, DatagramDnsQueryEncoder, DatagramDnsResponseEncoder, DatagramPacketEncoder, HttpObjectEncoder, LengthFieldPrepender, LineEncoder, StringEncoder, TcpDnsResponseEncoder, WebSocket13FrameEncoder, WebSocketExtensionEncoder

public abstract class MessageToMessageEncoder<I>
extends ChannelHandlerAdapter

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

{@code
     public class IntegerToStringEncoder extends
             MessageToMessageEncoder {

Constructor Summary

Constructors

Modifier	Constructor	Description
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(Class<? extends I> outboundMessageType)	Create a new instance

Method Summary

Modifier and Type	Method	Description
boolean	acceptOutboundMessage(Object msg)	Returns true if the given message should be handled.
protected void	encode(ChannelHandlerContext ctx, I msg, List<Object> out)	Encode from one message to another.
protected void	encodeAndClose(ChannelHandlerContext ctx, I msg, List<Object> out)	Encode from one message to another.
Future<Void>	write(ChannelHandlerContext ctx, Object msg)	Called once a write operation is made.

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, channelRead, channelReadComplete, channelRegistered, channelShutdown, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, flush, handlerAdded, handlerRemoved, isSharable, pendingOutboundBytes, read, register, sendOutboundEvent, shutdown

Constructor Detail

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(Class<? extends I> outboundMessageType)

Create a new instance

Parameters:

outboundMessageType - The type of messages to match and so encode

Method Detail

acceptOutboundMessage

public boolean acceptOutboundMessage(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

write

public Future<Void> write(ChannelHandlerContext ctx,
                          Object msg)

Description copied from interface: ChannelHandler

Called once a write operation is made. The write operation will write the messages through the ChannelPipeline. Those are then ready to be flushed to the actual Channel once Channel.flush() is called.

Parameters:

ctx - the ChannelHandlerContext for which the write operation is made

msg - the message to write

Returns:

the Future which will be notified once the operation completes.

encode

protected void encode(ChannelHandlerContext ctx,
                      I msg,
                      List<Object> out)
               throws Exception

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

The message will be disposed of after this call.

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

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to.

msg - the message to encode to another one.

out - the List into which produced output messages should be added.

Throws:

Exception - is thrown if an error occurs.

encodeAndClose

protected void encodeAndClose(ChannelHandlerContext ctx,
                              I msg,
                              List<Object> out)
                       throws Exception

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

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 encode(ChannelHandlerContext, Object, List) method.

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to.

msg - the message to encode to another one.

out - the List into which produced output messages should be added.

Throws:

Exception - is thrown if an error occurs.