Package org.jboss.netty.handler.codec.frame

Class LineBasedFrameDecoder

java.lang.Object

org.jboss.netty.channel.SimpleChannelUpstreamHandler

org.jboss.netty.handler.codec.frame.FrameDecoder

org.jboss.netty.handler.codec.frame.LineBasedFrameDecoder

All Implemented Interfaces:

ChannelHandler, ChannelUpstreamHandler, LifeCycleAwareChannelHandler

public class LineBasedFrameDecoder
extends FrameDecoder

A decoder that splits the received ChannelBuffers on line endings.

Both "\n" and "\r\n" are handled. For a more general delimiter-based decoder, see DelimiterBasedFrameDecoder.

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 int	discardedBytes
private boolean	discarding	True if we're discarding input because we're already over maxLength.
private boolean	failFast	Whether or not to throw an exception as soon as we exceed maxLength.
private int	maxLength	Maximum length of a frame we're willing to decode.
private boolean	stripDelimiter

Fields inherited from class org.jboss.netty.handler.codec.frame.FrameDecoder

cumulation, DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS

Constructor Summary

Constructors

Constructor	Description
LineBasedFrameDecoder(int maxLength)	Creates a new decoder.
LineBasedFrameDecoder(int maxLength, boolean stripDelimiter, boolean failFast)	Creates a new decoder.

Method Summary

Modifier and Type	Method	Description
protected java.lang.Object	decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer)	Decodes the received packets so far into a frame.
private void	fail(ChannelHandlerContext ctx, int length)
private void	fail(ChannelHandlerContext ctx, java.lang.String length)
private static int	findEndOfLine(ChannelBuffer buffer)	Returns the index in the buffer of the end of line found.

Methods inherited from class org.jboss.netty.handler.codec.frame.FrameDecoder

actualReadableBytes, afterAdd, afterRemove, appendToCumulation, beforeAdd, beforeRemove, channelClosed, channelDisconnected, cleanup, decodeLast, exceptionCaught, extractFrame, getMaxCumulationBufferCapacity, getMaxCumulationBufferComponents, internalBuffer, isUnfold, messageReceived, newCumulationBuffer, replace, setMaxCumulationBufferCapacity, setMaxCumulationBufferComponents, setUnfold, unfoldAndFireMessageReceived, updateCumulation

Methods inherited from class org.jboss.netty.channel.SimpleChannelUpstreamHandler

channelBound, channelConnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, handleUpstream, writeComplete

Methods inherited from class java.lang.Object

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

Field Detail

maxLength

private final int maxLength

Maximum length of a frame we're willing to decode.

failFast

private final boolean failFast

Whether or not to throw an exception as soon as we exceed maxLength.

stripDelimiter

private final boolean stripDelimiter

discarding

private boolean discarding

True if we're discarding input because we're already over maxLength.

discardedBytes

private int discardedBytes

Constructor Detail

LineBasedFrameDecoder

public LineBasedFrameDecoder(int maxLength)

Creates a new decoder.

Parameters:

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

LineBasedFrameDecoder

public LineBasedFrameDecoder(int maxLength,
                             boolean stripDelimiter,
                             boolean failFast)

Creates a new decoder.

Parameters:

maxLength - 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.

Method Detail

decode

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

Description copied from class: FrameDecoder

Decodes the received packets so far into a frame. If an sub-class wants to extract a frame out of the buffer it should use the FrameDecoder.extractFrame(ChannelBuffer, int, int) method, to make optimizations easier later.

Specified by:

decode in class FrameDecoder

Parameters:

ctx - the context of this handler

channel - the current channel

buffer - the cumulative buffer of received packets so far. Note that the buffer might be empty, which means you should not make an assumption that the buffer contains at least one byte in your decoder implementation.

Returns:

the decoded frame if a full frame was received and decoded. null if there's not enough data in the buffer to decode a frame.

Throws:

java.lang.Exception

fail

private void fail(ChannelHandlerContext ctx,
                  int length)

fail

private void fail(ChannelHandlerContext ctx,
                  java.lang.String length)

findEndOfLine

private static int findEndOfLine(ChannelBuffer buffer)

Returns the index in the buffer of the end of line found. Returns -1 if no end of line was found in the buffer.