public class DelimiterBasedFrameDecoder extends FrameDecoder
ChannelBuffer
s by one or more
delimiters. It is particularly useful for decoding the frames which ends
with a delimiter such as NUL
or
newline characters.
Delimiters
defines frequently used delimiters for convenience' sake.
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 | +----------+
ChannelHandler.Sharable
cumulation, DEFAULT_MAX_COMPOSITEBUFFER_COMPONENTS
Constructor and Description |
---|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
boolean failFast,
ChannelBuffer... delimiters)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
boolean failFast,
ChannelBuffer delimiter)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
ChannelBuffer... delimiters)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
ChannelBuffer delimiter)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
ChannelBuffer... delimiters)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
ChannelBuffer delimiter)
Creates a new instance.
|
Modifier and Type | Method and Description |
---|---|
protected Object |
decode(ChannelHandlerContext ctx,
Channel channel,
ChannelBuffer buffer)
Decodes the received packets so far into a frame.
|
actualReadableBytes, afterAdd, afterRemove, appendToCumulation, beforeAdd, beforeRemove, channelClosed, channelDisconnected, cleanup, decodeLast, exceptionCaught, extractFrame, getMaxCumulationBufferCapacity, getMaxCumulationBufferComponents, internalBuffer, isUnfold, messageReceived, newCumulationBuffer, replace, setMaxCumulationBufferCapacity, setMaxCumulationBufferComponents, setUnfold, unfoldAndFireMessageReceived, updateCumulation
channelBound, channelConnected, channelInterestChanged, channelOpen, channelUnbound, childChannelClosed, childChannelOpen, handleUpstream, writeComplete
public DelimiterBasedFrameDecoder(int maxFrameLength, ChannelBuffer delimiter)
maxFrameLength
- the maximum length of the decoded frame.
A TooLongFrameException
is thrown if
the length of the frame exceeds this value.delimiter
- the delimiterpublic DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, ChannelBuffer delimiter)
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 notdelimiter
- the delimiterpublic DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, ChannelBuffer delimiter)
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 notfailFast
- 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.delimiter
- the delimiterpublic DelimiterBasedFrameDecoder(int maxFrameLength, ChannelBuffer... delimiters)
maxFrameLength
- the maximum length of the decoded frame.
A TooLongFrameException
is thrown if
the length of the frame exceeds this value.delimiters
- the delimiterspublic DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, ChannelBuffer... delimiters)
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 notdelimiters
- the delimiterspublic DelimiterBasedFrameDecoder(int maxFrameLength, boolean stripDelimiter, boolean failFast, ChannelBuffer... delimiters)
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 notfailFast
- 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 delimitersprotected Object decode(ChannelHandlerContext ctx, Channel channel, ChannelBuffer buffer) throws Exception
FrameDecoder
FrameDecoder.extractFrame(ChannelBuffer, int, int)
method,
to make optimizations easier later.decode
in class FrameDecoder
ctx
- the context of this handlerchannel
- the current channelbuffer
- 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.null
if there's not enough data in the buffer to decode a frame.Exception
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