io.netty.handler.codec.string

Class StringDecoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.MessageToMessageDecoder<io.netty.buffer.ByteBuf>

io.netty.handler.codec.string.StringDecoder

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundHandler

@ChannelHandler.Sharable
public class StringDecoder
extends MessageToMessageDecoder<io.netty.buffer.ByteBuf>

Decodes a received ByteBuf 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 ByteBuf as a message:

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

Nested Class Summary

Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and 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 and Description
protected void	decode(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf msg, List<Object> out) Decode from one message to an other.

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

acceptInboundMessage, channelRead

Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter

channelActive, channelInactive, channelReadComplete, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught, userEventTriggered

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, handlerAdded, handlerRemoved, isSharable

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.netty.channel.ChannelHandler

handlerAdded, handlerRemoved

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

decode

protected void decode(io.netty.channel.ChannelHandlerContext ctx,
                      io.netty.buffer.ByteBuf msg,
                      List<Object> out)
               throws Exception

Description copied from class: MessageToMessageDecoder

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

Specified by:

decode in class MessageToMessageDecoder<io.netty.buffer.ByteBuf>

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageDecoder belongs to

msg - the message to decode to an other one

out - the List to which decoded messages should be added

Throws:

Exception - is thrown if an error occurs