Module io.netty5.codec

Package io.netty5.handler.codec.string

Class StringDecoder

java.lang.Object

io.netty5.channel.ChannelHandlerAdapter

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

io.netty5.handler.codec.string.StringDecoder

All Implemented Interfaces:

ChannelHandler

public class StringDecoder
extends MessageToMessageDecoder<Buffer>

Decodes a received Buffer into a String. Please note that this decoder must be used with a proper ByteToMessageDecoder such as DelimiterBasedFrameDecoder or LineBasedFrameDecoder if you are using a stream-based transport such as TCP/IP. A typical setup for a text-based line protocol in a TCP/IP socket would be:

 ChannelPipeline pipeline = ...;

 // Decoders
 pipeline.addLast("frameDecoder", new LineBasedFrameDecoder(80));
 pipeline.addLast("stringDecoder", new StringDecoder(CharsetUtil.UTF_8));

 // Encoder
 pipeline.addLast("stringEncoder", new StringEncoder(CharsetUtil.UTF_8));
 

and then you can use a String instead of a Buffer as a message:

 void channelRead(ChannelHandlerContext ctx, String msg) {
     ch.write("Did you say '" + msg + "'?\n");
 }
 

Constructor Summary

Constructors

Constructor	Description
StringDecoder()	Creates a new instance with the current system character set.
StringDecoder(Charset charset)	Creates a new instance with the specified character set.

Method Summary

Modifier and Type	Method	Description
protected void	decode(ChannelHandlerContext ctx, Buffer msg)	Decode from one message to another.
boolean	isSharable()	Returns true if this handler is sharable and thus can be added to more than one ChannelPipeline.

Methods inherited from class io.netty5.handler.codec.MessageToMessageDecoder

acceptInboundMessage, channelRead, decodeAndClose

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, pendingOutboundBytes, read, register, sendOutboundEvent, shutdown, write

Constructor Detail

StringDecoder

public StringDecoder()

Creates a new instance with the current system character set.

StringDecoder

public StringDecoder(Charset charset)

Creates a new instance with the specified character set.

Method Detail

isSharable

public boolean isSharable()

Description copied from interface: ChannelHandler

Returns true if this handler is sharable and thus can be added to more than one ChannelPipeline. By default, this method returns false. If this method returns false, you have to create a new handler instance every time you add it to a pipeline because it has unshared state such as member variables.

decode

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

Description copied from class: MessageToMessageDecoder

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 MessageToMessageDecoder.decodeAndClose(ChannelHandlerContext, Object) method.

Overrides:

decode in class MessageToMessageDecoder<Buffer>

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