Netty 5.0.0.Alpha5 · io.netty5.handler.codec.MessageToMessageDecoder

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.

public class StringToIntegerDecoder extends
            MessageToMessageDecoder<String> {

        @Override
        public void decode(ChannelHandlerContext ctx, String message,
                           List<Object> out) throws Exception {
            out.add(message.length());
        }
    }

Note that messages passed to decode(ChannelHandlerContext, Object) will be disposed of automatically.

To take control of the message lifetime, you should instead override the decodeAndClose(ChannelHandlerContext, Object) method.

Do not override both.

Modifier and Type	Field and Description
private final TypeParameterMatcher	matcher

Constructor Summary

Access	Constructor and 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> The type of messages to match and so decode inboundMessageType) Create a new instance

Method Summary

Modifier and Type	Method and Description
public boolean	acceptInboundMessage(Object msg) Returns `true` if the given message should be handled.
public void	channelRead(ChannelHandlerContext ctx, Object msg) Overrides default io.netty5.channel.ChannelHandler.channelRead. Invoked when the current `Channel` has read a message from the peer.
protected void	decode(ChannelHandlerContext the `ChannelHandlerContext` which this `MessageToMessageDecoder` belongs to ctx, I the message to decode to another one msg) Decode from one message to another.
protected void	decodeAndClose(ChannelHandlerContext the `ChannelHandlerContext` which this `MessageToMessageDecoder` belongs to ctx, I the message to decode to another one msg) Decode from one message to another.

Field Detail

matcher	back to summary
private final TypeParameterMatcher matcher

Constructor Detail

MessageToMessageDecoder	back to summary
protected MessageToMessageDecoder() Create a new instance which will try to detect the types to match out of the type parameter of the class.

MessageToMessageDecoder	back to summary
protected MessageToMessageDecoder(Class<? extends I> inboundMessageType) Create a new instance Parameters inboundMessageType:Class<? extends I> The type of messages to match and so decode

MessageToMessageDecoder

back to summary

protected MessageToMessageDecoder(Class<? extends I> inboundMessageType)

Create a new instance

Parameters

inboundMessageType:Class<? extends I>: The type of messages to match and so decode

Method Detail

acceptInboundMessage	back to summary
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`.

channelRead back to summary

channelRead	back to summary
public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception Overrides default io.netty5.channel.ChannelHandler.channelRead. Doc from io.netty5.channel.ChannelHandler.channelRead. Invoked when the current `Channel` has read a message from the peer. Annotations @Override

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

Overrides default io.netty5.channel.ChannelHandler.channelRead.

Doc from io.netty5.channel.ChannelHandler.channelRead.

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

Annotations

@Override

decode back to summary

decode	back to summary
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:ChannelHandlerContext the `ChannelHandlerContext` which this `MessageToMessageDecoder` belongs to msg:I the message to decode to another one Exceptions Exception: is thrown if an error occurs

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:ChannelHandlerContext: the ChannelHandlerContext which this MessageToMessageDecoder belongs to
msg:I: the message to decode to another one

Exceptions

Exception:: is thrown if an error occurs

decodeAndClose back to summary

decodeAndClose	back to summary
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:ChannelHandlerContext the `ChannelHandlerContext` which this `MessageToMessageDecoder` belongs to msg:I the message to decode to another one Exceptions Exception: is thrown if an error occurs

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:ChannelHandlerContext: the ChannelHandlerContext which this MessageToMessageDecoder belongs to
msg:I: the message to decode to another one

Exceptions

Exception:: is thrown if an error occurs

public abstract Class MessageToMessageDecoder<I>

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail