Netty 4.1.107.Final · io.netty.handler.codec.LineBasedFrameDecoder

A decoder that splits the received ByteBufs on line endings.

Both "\n" and "\r\n" are handled.

The byte stream is expected to be in UTF-8 character encoding or ASCII. The current implementation uses direct byte to char cast and then compares that char to a few low range ASCII characters like '\n' or '\r'. UTF-8 is not using low range [0..0x7F] byte values for multibyte codepoint representations therefore fully supported by this implementation.

For a more general delimiter-based decoder, see DelimiterBasedFrameDecoder.

Field Summary

Modifier and Type	Field and Description
private int	discardedBytes
private boolean	discarding True if we're discarding input because we're already over maxLength.
private final boolean	failFast Whether or not to throw an exception as soon as we exceed maxLength.
private final int	maxLength Maximum length of a frame we're willing to decode.
private int	offset Last scan position.
private final boolean	stripDelimiter

Inherited from io.netty.handler.codec.ByteToMessageDecoder:: COMPOSITE_CUMULATOR cumulation MERGE_CUMULATOR

Constructor Summary

Access Constructor and Description

Access	Constructor and Description
public	LineBasedFrameDecoder(final int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxLength) Creates a new decoder.
public	LineBasedFrameDecoder(final int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxLength, final boolean whether the decoded frame should strip out the delimiter or not stripDelimiter, final boolean 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. failFast) Creates a new decoder.

public

LineBasedFrameDecoder(final int

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

maxLength)

Creates a new decoder.

public

LineBasedFrameDecoder(final int

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

maxLength, final boolean

whether the decoded frame should strip out the delimiter or not

stripDelimiter, final boolean

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.

failFast)

Creates a new decoder.

Method Summary

Modifier and Type	Method and Description
protected final void	decode(ChannelHandlerContext the `ChannelHandlerContext` which this `ByteToMessageDecoder` belongs to ctx, ByteBuf the `ByteBuf` from which to read data in, List<Object> the `List` to which decoded messages should be added out) Implements abstract io.netty.handler.codec.ByteToMessageDecoder.decode. Decode the from one `ByteBuf` to an other.
protected Object	Returns: frame the `ByteBuf` which represent the frame or `null` if no frame could be created. decode(ChannelHandlerContext the `ChannelHandlerContext` which this `ByteToMessageDecoder` belongs to ctx, ByteBuf the `ByteBuf` from which to read data buffer) Create a frame out of the `ByteBuf` and return it.
private void	fail(final ChannelHandlerContext ctx, int length)
private void	fail(final ChannelHandlerContext ctx, String length)
private int	findEndOfLine(final ByteBuf buffer) Returns the index in the buffer of the end of line found.

Field Detail

discardedBytes	back to summary
private int discardedBytes

discarding	back to summary
private boolean discarding True if we're discarding input because we're already over maxLength.

failFast	back to summary
private final boolean failFast Whether or not to throw an exception as soon as we exceed maxLength.

maxLength	back to summary
private final int maxLength Maximum length of a frame we're willing to decode.

offset	back to summary
private int offset Last scan position.

stripDelimiter	back to summary
private final boolean stripDelimiter

Constructor Detail

LineBasedFrameDecoder back to summary

LineBasedFrameDecoder	back to summary
public LineBasedFrameDecoder(final int maxLength) Creates a new decoder. Parameters maxLength:int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value.

public LineBasedFrameDecoder(final int maxLength)

Creates a new decoder.

Parameters

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

LineBasedFrameDecoder back to summary

LineBasedFrameDecoder	back to summary
public LineBasedFrameDecoder(final int maxLength, final boolean stripDelimiter, final boolean failFast) Creates a new decoder. Parameters maxLength:int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. stripDelimiter:boolean whether the decoded frame should strip out the delimiter or not failFast:boolean 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.

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

Creates a new decoder.

Parameters

maxLength:int: the maximum length of the decoded frame. A TooLongFrameException is thrown if the length of the frame exceeds this value.
stripDelimiter:boolean: whether the decoded frame should strip out the delimiter or not
failFast:boolean: 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 back to summary

decode	back to summary
protected final void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception Implements abstract io.netty.handler.codec.ByteToMessageDecoder.decode. Doc from io.netty.handler.codec.ByteToMessageDecoder.decode. Decode the from one `ByteBuf` to an other. This method will be called till either the input `ByteBuf` has nothing to read when return from this method or till nothing was read from the input `ByteBuf`. Parameters ctx:ChannelHandlerContext the `ChannelHandlerContext` which this `ByteToMessageDecoder` belongs to in:ByteBuf the `ByteBuf` from which to read data out:List<Object> the `List` to which decoded messages should be added Annotations @Override Exceptions Exception: is thrown if an error occurs

protected final void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out) throws Exception

Implements abstract io.netty.handler.codec.ByteToMessageDecoder.decode.

Doc from io.netty.handler.codec.ByteToMessageDecoder.decode.

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

Parameters

ctx:ChannelHandlerContext: the ChannelHandlerContext which this ByteToMessageDecoder belongs to
in:ByteBuf: the ByteBuf from which to read data
out:List<Object>: the List to which decoded messages should be added

Annotations

@Override

Exceptions

Exception:: is thrown if an error occurs

decode back to summary

decode	back to summary
protected Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception Create a frame out of the `ByteBuf` and return it. Parameters ctx:ChannelHandlerContext the `ChannelHandlerContext` which this `ByteToMessageDecoder` belongs to buffer:ByteBuf the `ByteBuf` from which to read data Returns:Object frame the `ByteBuf` which represent the frame or `null` if no frame could be created.

protected Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws Exception

Create a frame out of the ByteBuf and return it.

Parameters

ctx:ChannelHandlerContext: the ChannelHandlerContext which this ByteToMessageDecoder belongs to
buffer:ByteBuf: the ByteBuf from which to read data

Returns:Object

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

fail	back to summary
private void fail(final ChannelHandlerContext ctx, int length)

fail	back to summary
private void fail(final ChannelHandlerContext ctx, String length)

findEndOfLine	back to summary
private int findEndOfLine(final ByteBuf 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.

public Class LineBasedFrameDecoder

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail