public class DelimiterBasedFrameDecoder extends ByteToMessageDecoder
ByteBufs 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 | +----------+
ByteToMessageDecoder.CumulatorChannelHandler.Sharable| Modifier and Type | Field and Description |
|---|---|
private ByteBuf[] |
delimiters |
private boolean |
discardingTooLongFrame |
private boolean |
failFast |
private LineBasedFrameDecoder |
lineBasedDecoder
Set only when decoding with "\n" and "\r\n" as the delimiter.
|
private int |
maxFrameLength |
private boolean |
stripDelimiter |
private int |
tooLongFrameLength |
COMPOSITE_CUMULATOR, cumulation, MERGE_CUMULATOR| Constructor and Description |
|---|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
boolean failFast,
ByteBuf... delimiters)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
boolean failFast,
ByteBuf delimiter)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
ByteBuf... delimiters)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
boolean stripDelimiter,
ByteBuf delimiter)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
ByteBuf... delimiters)
Creates a new instance.
|
DelimiterBasedFrameDecoder(int maxFrameLength,
ByteBuf delimiter)
Creates a new instance.
|
| Modifier and Type | Method and Description |
|---|---|
protected java.lang.Object |
decode(ChannelHandlerContext ctx,
ByteBuf buffer)
Create a frame out of the
ByteBuf and return it. |
protected void |
decode(ChannelHandlerContext ctx,
ByteBuf in,
java.util.List<java.lang.Object> out)
Decode the from one
ByteBuf to an other. |
private void |
fail(long frameLength) |
private static int |
indexOf(ByteBuf haystack,
ByteBuf needle)
Returns the number of bytes between the readerIndex of the haystack and
the first needle found in the haystack.
|
private static boolean |
isLineBased(ByteBuf[] delimiters)
Returns true if the delimiters are "\n" and "\r\n".
|
private boolean |
isSubclass()
Return
true if the current instance is a subclass of DelimiterBasedFrameDecoder |
private static void |
validateDelimiter(ByteBuf delimiter) |
private static void |
validateMaxFrameLength(int maxFrameLength) |
actualReadableBytes, callDecode, channelInactive, channelInputClosed, channelRead, channelReadComplete, decodeLast, decodeRemovalReentryProtection, discardSomeReadBytes, expandCumulation, fireChannelRead, fireChannelRead, handlerRemoved, handlerRemoved0, internalBuffer, isSingleDecode, setCumulator, setDiscardAfterReads, setSingleDecode, userEventTriggeredchannelActive, channelRegistered, channelUnregistered, channelWritabilityChanged, exceptionCaughtensureNotSharable, handlerAdded, isSharableclone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, waithandlerAddedprivate final ByteBuf[] delimiters
private final int maxFrameLength
private final boolean stripDelimiter
private final boolean failFast
private boolean discardingTooLongFrame
private int tooLongFrameLength
private final LineBasedFrameDecoder lineBasedDecoder
public DelimiterBasedFrameDecoder(int maxFrameLength,
ByteBuf 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,
ByteBuf 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,
ByteBuf 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,
ByteBuf... 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,
ByteBuf... 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,
ByteBuf... 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 delimitersprivate static boolean isLineBased(ByteBuf[] delimiters)
private boolean isSubclass()
true if the current instance is a subclass of DelimiterBasedFrameDecoderprotected final void decode(ChannelHandlerContext ctx, ByteBuf in, java.util.List<java.lang.Object> out) throws java.lang.Exception
ByteToMessageDecoderByteBuf 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.decode in class ByteToMessageDecoderctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs toin - the ByteBuf from which to read dataout - the List to which decoded messages should be addedjava.lang.Exception - is thrown if an error occursprotected java.lang.Object decode(ChannelHandlerContext ctx, ByteBuf buffer) throws java.lang.Exception
ByteBuf and return it.ctx - the ChannelHandlerContext which this ByteToMessageDecoder belongs tobuffer - the ByteBuf from which to read dataByteBuf which represent the frame or null if no frame could
be created.java.lang.Exceptionprivate void fail(long frameLength)
private static int indexOf(ByteBuf haystack, ByteBuf needle)
private static void validateDelimiter(ByteBuf delimiter)
private static void validateMaxFrameLength(int maxFrameLength)