io.netty.handler.codec.string

Class StringEncoder

java.lang.Object

io.netty.channel.ChannelHandlerAdapter

io.netty.channel.ChannelOutboundHandlerAdapter

io.netty.handler.codec.MessageToMessageEncoder<java.lang.CharSequence>

io.netty.handler.codec.string.StringEncoder

All Implemented Interfaces:

ChannelHandler, ChannelOutboundHandler

@ChannelHandler.Sharable
public class StringEncoder
extends MessageToMessageEncoder<java.lang.CharSequence>

Encodes the requested String into a ByteBuf. 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

ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
StringEncoder() Creates a new instance with the current system character set.
StringEncoder(java.nio.charset.Charset charset) Creates a new instance with the specified character set.

Method Summary

Modifier and Type	Method and Description
protected void	encode(ChannelHandlerContext ctx, java.lang.CharSequence msg, java.util.List<java.lang.Object> out) Encode from one message to an other.

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

acceptOutboundMessage, write

Methods inherited from class io.netty.channel.ChannelOutboundHandlerAdapter

bind, close, connect, deregister, disconnect, flush, read

Methods inherited from class io.netty.channel.ChannelHandlerAdapter

ensureNotSharable, exceptionCaught, 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

exceptionCaught, handlerAdded, handlerRemoved

Constructor Detail

StringEncoder

public StringEncoder()

Creates a new instance with the current system character set.

StringEncoder

public StringEncoder(java.nio.charset.Charset charset)

Creates a new instance with the specified character set.

Method Detail

encode

protected void encode(ChannelHandlerContext ctx,
                      java.lang.CharSequence msg,
                      java.util.List<java.lang.Object> out)
               throws java.lang.Exception

Description copied from class: MessageToMessageEncoder

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

Specified by:

encode in class MessageToMessageEncoder<java.lang.CharSequence>

Parameters:

ctx - the ChannelHandlerContext which this MessageToMessageEncoder belongs to

msg - the message to encode to an other one

out - the List into which the encoded msg should be added needs to do some kind of aggregation

Throws:

java.lang.Exception - is thrown if an error occurs