Package org.springframework.messaging.simp.stomp

Class BufferingStompDecoder

  • public class BufferingStompDecoder
extends Object
    An extension of StompDecoder that buffers content remaining in the input ByteBuffer after the parent class has read all (complete) STOMP frames from it. The remaining content represents an incomplete STOMP frame. When called repeatedly with additional data, the decode method returns one or more messages or, if there is not enough data still, continues to buffer.

    A single instance of this decoder can be invoked repeatedly to read all messages from a single stream (e.g. WebSocket session) as long as decoding does not fail. If there is an exception, StompDecoder instance should not be used any more as its internal state is not guaranteed to be consistent. It is expected that the underlying session is closed at that point.

    Since:
    4.0.3
    Author:
    Rossen Stoyanchev
    See Also:
    StompDecoder

    • Constructor Detail

      • BufferingStompDecoder

        public BufferingStompDecoder​(StompDecoder stompDecoder,
                             int bufferSizeLimit)
        Create a new BufferingStompDecoder wrapping the given StompDecoder.
        Parameters:
        stompDecoder - the target decoder to wrap
        bufferSizeLimit - the buffer size limit

    • Method Detail

      • getBufferSizeLimit

        public final int getBufferSizeLimit()
        Return the configured buffer size limit.

      • decode

        public List<Message<byte[]>> decode​(ByteBuffer newBuffer)
        Decodes one or more STOMP frames from the given ByteBuffer into a list of Messages.

        If there was enough data to parse a "content-length" header, then the value is used to determine how much more data is needed before a new attempt to decode is made.

        If there was not enough data to parse the "content-length", or if there is "content-length" header, every subsequent call to decode attempts to parse again with all available data. Therefore the presence of a "content-length" header helps to optimize the decoding of large messages.

        Parameters:
        newBuffer - a buffer containing new data to decode
        Returns:
        decoded messages or an empty list
        Throws:
        StompConversionException - raised in case of decoding issues

      • getBufferSize

        public int getBufferSize()
        Calculate the current buffer size.