Module io.netty5.codec

Package io.netty5.handler.codec

Class DelimiterBasedFrameDecoder

java.lang.Object

io.netty5.channel.ChannelHandlerAdapter

io.netty5.handler.codec.ByteToMessageDecoder

io.netty5.handler.codec.DelimiterBasedFrameDecoder

All Implemented Interfaces:

ChannelHandler

public class DelimiterBasedFrameDecoder
extends ByteToMessageDecoder

A decoder that splits the received Buffers 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 class io.netty5.handler.codec.ByteToMessageDecoder

ByteToMessageDecoder.Cumulator

Field Summary

Fields inherited from class io.netty5.handler.codec.ByteToMessageDecoder

COMPOSITE_CUMULATOR, MERGE_CUMULATOR

Constructor Summary

Constructors

Constructor	Description
DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, Buffer... delimiters)	Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, Buffer... delimiters)	Creates a new instance.
DelimiterBasedFrameDecoder(int maxFrameLength, Buffer... delimiters)	Creates a new instance.

Method Summary

Modifier and Type	Method	Description
protected void	decode(ChannelHandlerContext ctx, Buffer in)	Decode the from one Buffer to another.
protected Object	decode0(ChannelHandlerContext ctx, Buffer buffer)	Create a frame out of the Buffer and return it.
protected void	handlerRemoved0(ChannelHandlerContext ctx)	Gets called after the ByteToMessageDecoder was removed from the actual context and it doesn't handle events anymore.

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

actualReadableBytes, channelInactive, channelRead, channelReadComplete, channelShutdown, decodeLast, discardSomeReadBytes, handlerAdded, handlerAdded0, handlerRemoved, internalBuffer, isSharable, isSingleDecode, setSingleDecode

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, channelInboundEvent, channelRegistered, channelUnregistered, channelWritabilityChanged, close, connect, deregister, disconnect, flush, pendingOutboundBytes, read, register, sendOutboundEvent, shutdown, write

Constructor Detail

DelimiterBasedFrameDecoder

public DelimiterBasedFrameDecoder(int maxFrameLength,
                                  Buffer... 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,
                                  Buffer... 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,
                                  Buffer... 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

protected final void decode(ChannelHandlerContext ctx,
                            Buffer in)
                     throws Exception

Description copied from class: ByteToMessageDecoder

Decode the from one Buffer to another. This method will be called till either the input Buffer has nothing to read when return from this method or till nothing was read from the input Buffer.

Specified by:

decode in class ByteToMessageDecoder

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

in - the Buffer from which to read data

Throws:

Exception - is thrown if an error occurs

decode0

protected Object decode0(ChannelHandlerContext ctx,
                         Buffer buffer)

Create a frame out of the Buffer and return it.

Parameters:

ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs to

buffer - the Buffer from which to read data

Returns:

frame the Buffer which represent the frame or null if no frame could be created.

handlerRemoved0

protected void handlerRemoved0(ChannelHandlerContext ctx)
                        throws Exception

Description copied from class: ByteToMessageDecoder

Gets called after the ByteToMessageDecoder was removed from the actual context and it doesn't handle events anymore.

Overrides:

handlerRemoved0 in class ByteToMessageDecoder

Throws:

Exception