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

A decoder that splits the received 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.

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 |
+--------------+

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 |
+----------+

Field Summary

Modifier and Type	Field and Description
private final ByteBuf[]	delimiters
private boolean	discardingTooLongFrame
private final boolean	failFast
private final LineBasedFrameDecoder	lineBasedDecoder Set only when decoding with "\n" and "\r\n" as the delimiter.
private final int	maxFrameLength
private final boolean	stripDelimiter
private int	tooLongFrameLength

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

Constructor Summary

Access	Constructor and Description
public	DelimiterBasedFrameDecoder(int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxFrameLength, ByteBuf the delimiter delimiter) Creates a new instance.
public	DelimiterBasedFrameDecoder(int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxFrameLength, boolean whether the decoded frame should strip out the delimiter or not stripDelimiter, ByteBuf the delimiter delimiter) Creates a new instance.
public	DelimiterBasedFrameDecoder(int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxFrameLength, boolean whether the decoded frame should strip out the delimiter or not stripDelimiter, 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, ByteBuf the delimiter delimiter) Creates a new instance.
public	DelimiterBasedFrameDecoder(int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxFrameLength, ByteBuf... the delimiters delimiters) Creates a new instance.
public	DelimiterBasedFrameDecoder(int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxFrameLength, boolean whether the decoded frame should strip out the delimiter or not stripDelimiter, ByteBuf... the delimiters delimiters) Creates a new instance.
public	DelimiterBasedFrameDecoder(int the maximum length of the decoded frame. A `TooLongFrameException` is thrown if the length of the frame exceeds this value. maxFrameLength, boolean whether the decoded frame should strip out the delimiter or not stripDelimiter, 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, ByteBuf... the delimiters delimiters) Creates a new instance.

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(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(final 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)

Field Detail

delimiters	back to summary
private final ByteBuf[] delimiters

discardingTooLongFrame	back to summary
private boolean discardingTooLongFrame

failFast	back to summary
private final boolean failFast

lineBasedDecoder	back to summary
private final LineBasedFrameDecoder lineBasedDecoder Set only when decoding with "\n" and "\r\n" as the delimiter.

maxFrameLength	back to summary
private final int maxFrameLength

stripDelimiter	back to summary
private final boolean stripDelimiter

tooLongFrameLength	back to summary
private int tooLongFrameLength