Package io.netty.handler.codec
Class LineBasedFrameDecoder
- java.lang.Object
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- io.netty.channel.ChannelHandlerAdapter
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- io.netty.channel.ChannelInboundHandlerAdapter
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- io.netty.handler.codec.ByteToMessageDecoder
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- io.netty.handler.codec.LineBasedFrameDecoder
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- All Implemented Interfaces:
ChannelHandler,ChannelInboundHandler
- Direct Known Subclasses:
SmtpResponseDecoder
public class LineBasedFrameDecoder extends ByteToMessageDecoder
A decoder that splits the receivedByteBufs 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
bytetocharcast and then compares thatcharto 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.
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Nested Class Summary
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Nested classes/interfaces inherited from class io.netty.handler.codec.ByteToMessageDecoder
ByteToMessageDecoder.Cumulator
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Nested classes/interfaces inherited from interface io.netty.channel.ChannelHandler
ChannelHandler.Sharable
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Field Summary
Fields Modifier and Type Field Description private intdiscardedBytesprivate booleandiscardingTrue if we're discarding input because we're already over maxLength.private booleanfailFastWhether or not to throw an exception as soon as we exceed maxLength.private intmaxLengthMaximum length of a frame we're willing to decode.private intoffsetLast scan position.private booleanstripDelimiter-
Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder
COMPOSITE_CUMULATOR, cumulation, MERGE_CUMULATOR
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Constructor Summary
Constructors Constructor Description LineBasedFrameDecoder(int maxLength)Creates a new decoder.LineBasedFrameDecoder(int maxLength, boolean stripDelimiter, boolean failFast)Creates a new decoder.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected java.lang.Objectdecode(ChannelHandlerContext ctx, ByteBuf buffer)Create a frame out of theByteBufand return it.protected voiddecode(ChannelHandlerContext ctx, ByteBuf in, java.util.List<java.lang.Object> out)Decode the from oneByteBufto an other.private voidfail(ChannelHandlerContext ctx, int length)private voidfail(ChannelHandlerContext ctx, java.lang.String length)private intfindEndOfLine(ByteBuf buffer)Returns the index in the buffer of the end of line found.-
Methods inherited from class io.netty.handler.codec.ByteToMessageDecoder
actualReadableBytes, callDecode, channelInactive, channelInputClosed, channelRead, channelReadComplete, decodeLast, decodeRemovalReentryProtection, discardSomeReadBytes, expandCumulation, fireChannelRead, fireChannelRead, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setDiscardAfterReads, setSingleDecode, userEventTriggered
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Methods inherited from class io.netty.channel.ChannelInboundHandlerAdapter
channelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaught
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Methods inherited from class io.netty.channel.ChannelHandlerAdapter
ensureNotSharable, handlerAdded, isSharable
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Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
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Methods inherited from interface io.netty.channel.ChannelHandler
handlerAdded
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Field Detail
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maxLength
private final int maxLength
Maximum length of a frame we're willing to decode.
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failFast
private final boolean failFast
Whether or not to throw an exception as soon as we exceed maxLength.
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stripDelimiter
private final boolean stripDelimiter
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discarding
private boolean discarding
True if we're discarding input because we're already over maxLength.
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discardedBytes
private int discardedBytes
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offset
private int offset
Last scan position.
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Constructor Detail
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LineBasedFrameDecoder
public LineBasedFrameDecoder(int maxLength)
Creates a new decoder.- Parameters:
maxLength- the maximum length of the decoded frame. ATooLongFrameExceptionis thrown if the length of the frame exceeds this value.
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LineBasedFrameDecoder
public LineBasedFrameDecoder(int maxLength, boolean stripDelimiter, boolean failFast)Creates a new decoder.- Parameters:
maxLength- the maximum length of the decoded frame. ATooLongFrameExceptionis thrown if the length of the frame exceeds this value.stripDelimiter- whether the decoded frame should strip out the delimiter or notfailFast- If true, aTooLongFrameExceptionis 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, aTooLongFrameExceptionis thrown after the entire frame that exceeds maxFrameLength has been read.
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Method Detail
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decode
protected final void decode(ChannelHandlerContext ctx, ByteBuf in, java.util.List<java.lang.Object> out) throws java.lang.Exception
Description copied from class:ByteToMessageDecoderDecode the from oneByteBufto an other. This method will be called till either the inputByteBufhas nothing to read when return from this method or till nothing was read from the inputByteBuf.- Specified by:
decodein classByteToMessageDecoder- Parameters:
ctx- theChannelHandlerContextwhich thisByteToMessageDecoderbelongs toin- theByteBuffrom which to read dataout- theListto which decoded messages should be added- Throws:
java.lang.Exception- is thrown if an error occurs
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decode
protected java.lang.Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws java.lang.Exception
Create a frame out of theByteBufand return it.- Parameters:
ctx- theChannelHandlerContextwhich thisByteToMessageDecoderbelongs tobuffer- theByteBuffrom which to read data- Returns:
- frame the
ByteBufwhich represent the frame ornullif no frame could be created. - Throws:
java.lang.Exception
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fail
private void fail(ChannelHandlerContext ctx, int length)
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fail
private void fail(ChannelHandlerContext ctx, java.lang.String length)
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findEndOfLine
private int findEndOfLine(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.
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