Package org.jboss.netty.handler.codec.string

Class StringDecoder

java.lang.Object

org.jboss.netty.handler.codec.oneone.OneToOneDecoder

org.jboss.netty.handler.codec.string.StringDecoder

All Implemented Interfaces:

ChannelHandler, ChannelUpstreamHandler

@Sharable
public class StringDecoder
extends OneToOneDecoder

Decodes a received ChannelBuffer into a String. Please note that this decoder must be used with a proper FrameDecoder such as DelimiterBasedFrameDecoder 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 DelimiterBasedFrameDecoder(80, Delimiters.lineDelimiter()));
 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 ChannelBuffer as a message:

 void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
     String msg = (String) e.getMessage();
     ch.write("Did you say '" + msg + "'?\n");
 }
 

Nested Class Summary

Nested classes/interfaces inherited from interface org.jboss.netty.channel.ChannelHandler

ChannelHandler.Sharable

Field Summary

Fields

Modifier and Type	Field	Description
private java.nio.charset.Charset	charset

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
protected java.lang.Object	decode(ChannelHandlerContext ctx, Channel channel, java.lang.Object msg)	Transforms the specified received message into another message and return the transformed message.

Methods inherited from class org.jboss.netty.handler.codec.oneone.OneToOneDecoder

handleUpstream

Methods inherited from class java.lang.Object

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

Field Detail

charset

private final java.nio.charset.Charset charset

Constructor Detail

StringDecoder

public StringDecoder()

Creates a new instance with the current system character set.

StringDecoder

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

Creates a new instance with the specified character set.

Method Detail

decode

protected java.lang.Object decode(ChannelHandlerContext ctx,
                                  Channel channel,
                                  java.lang.Object msg)
                           throws java.lang.Exception

Description copied from class: OneToOneDecoder

Transforms the specified received message into another message and return the transformed message. Return null if the received message is supposed to be discarded.

Specified by:

decode in class OneToOneDecoder

Throws:

java.lang.Exception