io.netty.handler.codec

Class DelimiterBasedFrameDecoder

java.lang.Object

io.netty.channel.ChannelStateHandlerAdapter

io.netty.channel.ChannelInboundHandlerAdapter

io.netty.handler.codec.ByteToMessageDecoder<Object>

io.netty.handler.codec.DelimiterBasedFrameDecoder

All Implemented Interfaces:

io.netty.channel.ChannelHandler, io.netty.channel.ChannelInboundByteHandler, io.netty.channel.ChannelInboundHandler, io.netty.channel.ChannelStateHandler

public class DelimiterBasedFrameDecoder
extends ByteToMessageDecoder<Object>

A decoder that splits the received ByteBufs by one or more delimiters. It is particularly useful for decoding the frames which ends with a delimiter such as NUL or newline characters.

Predefined delimiters

Delimiters defines frequently used delimiters for convenience' sake.

Specifying more than one delimiter

DelimiterBasedFrameDecoder allows you to specify more than one delimiter. If more than one delimiter is found in the buffer, it chooses the delimiter which produces the shortest frame. For example, if you have the following data in the buffer:

 +--------------+
 | ABC\nDEF\r\n |
 +--------------+
 

a DelimiterBasedFrameDecoder(Delimiters.lineDelimiter()) will choose '\n' as the first delimiter and produce two frames:

 +-----+-----+
 | ABC | DEF |
 +-----+-----+
 

rather than incorrectly choosing '\r\n' as the first delimiter:

 +----------+
 | ABC\nDEF |
 +----------+
 

Nested Class Summary

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

io.netty.channel.ChannelHandler.Sharable

Constructor Summary

Constructors

Constructor and Description
DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, io.netty.buffer.ByteBuf... delimiters) Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, io.netty.buffer.ByteBuf delimiter) Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, io.netty.buffer.ByteBuf... delimiters) Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, io.netty.buffer.ByteBuf delimiter) Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, io.netty.buffer.ByteBuf... delimiters) Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, io.netty.buffer.ByteBuf delimiter) Creates a new instance.

Method Summary

Methods

Modifier and Type	Method and Description
Object	decode(io.netty.channel.ChannelHandlerContext ctx, io.netty.buffer.ByteBuf buffer)

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

beforeAdd, callDecode, channelInactive, decodeLast, inboundBufferUpdated, newInboundBuffer, replace

Methods inherited from class io.netty.channel.ChannelStateHandlerAdapter

afterAdd, afterRemove, beforeRemove, channelActive, channelRegistered, channelUnregistered, exceptionCaught, userEventTriggered

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.ChannelStateHandler

channelActive, channelRegistered, channelUnregistered

Methods inherited from interface io.netty.channel.ChannelHandler

afterAdd, afterRemove, beforeRemove, exceptionCaught, userEventTriggered

Constructor Detail

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                          io.netty.buffer.ByteBuf delimiter)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

delimiter - the delimiter

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                          boolean stripDelimiter,
                          io.netty.buffer.ByteBuf delimiter)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

delimiter - the delimiter

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                          boolean stripDelimiter,
                          boolean failFast,
                          io.netty.buffer.ByteBuf delimiter)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

failFast - If true, a TooLongFrameException is thrown as soon as the decoder notices the length of the frame will exceed maxFrameLength regardless of whether the entire frame has been read. If false, a TooLongFrameException is thrown after the entire frame that exceeds maxFrameLength has been read.

delimiter - the delimiter

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                          io.netty.buffer.ByteBuf... delimiters)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

delimiters - the delimiters

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                          boolean stripDelimiter,
                          io.netty.buffer.ByteBuf... delimiters)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

delimiters - the delimiters

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                          boolean stripDelimiter,
                          boolean failFast,
                          io.netty.buffer.ByteBuf... delimiters)

Creates a new instance.

Parameters:

maxFrameLength - the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.

stripDelimiter - whether the decoded frame should strip out the delimiter or not

failFast - If true, a TooLongFrameException is thrown as soon as the decoder notices the length of the frame will exceed maxFrameLength regardless of whether the entire frame has been read. If false, a TooLongFrameException is thrown after the entire frame that exceeds maxFrameLength has been read.

delimiters - the delimiters

Method Detail

decode

public Object decode(io.netty.channel.ChannelHandlerContext ctx,
            io.netty.buffer.ByteBuf buffer)
              throws Exception

Specified by:

decode in class ByteToMessageDecoder<Object>

Throws:

Exception