Package io.netty.handler.codec
Class DelimiterBasedFrameDecoder
- 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.DelimiterBasedFrameDecoder
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- All Implemented Interfaces:
ChannelHandler
,ChannelInboundHandler
public class DelimiterBasedFrameDecoder extends ByteToMessageDecoder
A decoder that splits the receivedByteBuf
s by one or more delimiters. It is particularly useful for decoding the frames which ends with a delimiter such asNUL
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 | +--------------+
aDelimiterBasedFrameDecoder
(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 | +----------+
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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
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Fields inherited from class io.netty.handler.codec.ByteToMessageDecoder
COMPOSITE_CUMULATOR, MERGE_CUMULATOR
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Constructor Summary
Constructors Constructor Description DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, ByteBuf delimiter)
Creates a new instance.DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, ByteBuf... delimiters)
Creates a new instance.DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, ByteBuf delimiter)
Creates a new instance.DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, ByteBuf... delimiters)
Creates a new instance.DelimiterBasedFrameDecoder(int maxFrameLength, ByteBuf delimiter)
Creates a new instance.DelimiterBasedFrameDecoder(int maxFrameLength, ByteBuf... delimiters)
Creates a new instance.
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description protected java.lang.Object
decode(ChannelHandlerContext ctx, ByteBuf buffer)
Create a frame out of theByteBuf
and return it.protected void
decode(ChannelHandlerContext ctx, ByteBuf in, java.util.List<java.lang.Object> out)
Decode the from oneByteBuf
to an other.-
Methods inherited from class io.netty.handler.codec.ByteToMessageDecoder
actualReadableBytes, callDecode, channelInactive, channelRead, channelReadComplete, decodeLast, discardSomeReadBytes, 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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Constructor Detail
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DelimiterBasedFrameDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength, ByteBuf delimiter)
Creates a new instance.- Parameters:
maxFrameLength
- the maximum length of the decoded frame. ATooLongFrameException
is thrown if the length of the frame exceeds this value.delimiter
- the delimiter
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DelimiterBasedFrameDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, ByteBuf delimiter)
Creates a new instance.- Parameters:
maxFrameLength
- the maximum length of the decoded frame. ATooLongFrameException
is thrown if the length of the frame exceeds this value.stripDelimiter
- whether the decoded frame should strip out the delimiter or notdelimiter
- the delimiter
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DelimiterBasedFrameDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, ByteBuf delimiter)
Creates a new instance.- Parameters:
maxFrameLength
- the maximum length of the decoded frame. ATooLongFrameException
is thrown if the length of the frame exceeds this value.stripDelimiter
- whether the decoded frame should strip out the delimiter or notfailFast
- If true, aTooLongFrameException
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, aTooLongFrameException
is thrown after the entire frame that exceeds maxFrameLength has been read.delimiter
- the delimiter
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DelimiterBasedFrameDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength, ByteBuf... delimiters)
Creates a new instance.- Parameters:
maxFrameLength
- the maximum length of the decoded frame. ATooLongFrameException
is thrown if the length of the frame exceeds this value.delimiters
- the delimiters
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DelimiterBasedFrameDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, ByteBuf... delimiters)
Creates a new instance.- Parameters:
maxFrameLength
- the maximum length of the decoded frame. ATooLongFrameException
is thrown if the length of the frame exceeds this value.stripDelimiter
- whether the decoded frame should strip out the delimiter or notdelimiters
- the delimiters
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DelimiterBasedFrameDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, ByteBuf... delimiters)
Creates a new instance.- Parameters:
maxFrameLength
- the maximum length of the decoded frame. ATooLongFrameException
is thrown if the length of the frame exceeds this value.stripDelimiter
- whether the decoded frame should strip out the delimiter or notfailFast
- If true, aTooLongFrameException
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, aTooLongFrameException
is thrown after the entire frame that exceeds maxFrameLength has been read.delimiters
- the delimiters
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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:ByteToMessageDecoder
Decode the from oneByteBuf
to an other. This method will be called till either the inputByteBuf
has nothing to read when return from this method or till nothing was read from the inputByteBuf
.- Specified by:
decode
in classByteToMessageDecoder
- Parameters:
ctx
- theChannelHandlerContext
which thisByteToMessageDecoder
belongs toin
- theByteBuf
from which to read dataout
- theList
to 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 theByteBuf
and return it.- Parameters:
ctx
- theChannelHandlerContext
which thisByteToMessageDecoder
belongs tobuffer
- theByteBuf
from which to read data- Returns:
- frame the
ByteBuf
which represent the frame ornull
if no frame could be created. - Throws:
java.lang.Exception
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