Package ej.websocket.frame

Class RawFrame

  • public final class RawFrame
extends Object
    This is just a convenient class to encapsulate a byte array that contains a complete websocket frame. It provides methods to get information and data from the frame.

    The structure of a frame is described in RFC6455, section 5.2. Base Framing Protocol.

    • Field Detail

      • OPCODE_CONTINUATION_FRAME

        public static final byte OPCODE_CONTINUATION_FRAME
        Opcode to denote a continuation frame.
        See Also:
        Constant Field Values

      • OPCODE_TEXT_FRAME

        public static final byte OPCODE_TEXT_FRAME
        Opcode to denote a text frame.
        See Also:
        Constant Field Values

      • OPCODE_BINARY_FRAME

        public static final byte OPCODE_BINARY_FRAME
        Opcode to denote a binary frame.
        See Also:
        Constant Field Values

      • OPCODE_CONNECTION_CLOSE

        public static final byte OPCODE_CONNECTION_CLOSE
        Opcode to denote a connection close.
        See Also:
        Constant Field Values

      • OPCODE_PING

        public static final byte OPCODE_PING
        Opcode to denote a ping.
        See Also:
        Constant Field Values

      • OPCODE_PONG

        public static final byte OPCODE_PONG
        Opcode to denote a pong.
        See Also:
        Constant Field Values

    • Constructor Detail

      • RawFrame

        public RawFrame​(byte[] bytes)
         throws IllegalArgumentException
        bytes will be copied internally so that it is not tied to the newly created instance and can then be reused.
        Parameters:
        bytes - the data used to create the frame
        Throws:
        IllegalArgumentException - if bytes is null

    • Method Detail

      • getBytes

        public byte[] getBytes()
        Note: this is not a copy of the internal representation. Handle it with care so as not to alter the frame.
        Returns:
        the byte array of the frame

      • getFIN

        public byte getFIN()
        FIN is a bit. It is the LSB of the returned byte.
        Returns:
        FIN

      • getRSV

        public byte getRSV()
        RSV are 3 bits. They are the LSB of the returned byte.
        Returns:
        RSV[1..3]

      • getOpcode

        public byte getOpcode()
        Opcode is 4 bits. They are the LSB of the returned byte.
        Returns:
        opcode

      • hasValidOpcode

        public boolean hasValidOpcode()
        Test the opcode of this frame against possible opcodes provided by RFC6455.
        Returns:
        'true' if 'code' is a valid opcode, 'false' otherwise

      • getMASK

        public byte getMASK()
        MASK is a bit. It is the LSB of the returned byte.
        Returns:
        FIN

      • isControlFrame

        public boolean isControlFrame()
        Tell whether this frame is a control frame or not.
        Returns:
        'true' is this is a control frame, 'false' otherwise

      • isMasked

        public boolean isMasked()
        A convenient method to test whether the frame is masked or not.
        Returns:
        true if MASK bit is set to 1; false otherwise

      • isValid

        public boolean isValid()
                throws IOException
        Tell whether is valid or not, according to the RFC6455.
        Returns:
        'true' if the frame is valid, 'false' otherwise
        Throws:
        IOException - if the frame does not respect the RFC6455
        UnsupportedEncodingException - if the frame does not validate the UTF8 format

      • getLength

        public byte getLength()
        A frame has a field called payload length. This is the value returned here. This may not be the actual length since a frame can have an additional field called "extended payload length".
        Returns:
        the payload length

      • hasExtendedLength

        public boolean hasExtendedLength()
        Tell whether this frame has an extended length field.
        Returns:
        'true' if it has an extended length field.

      • hasVeryExtendedLength

        public boolean hasVeryExtendedLength()
        Tell whether this frame has an extended length field.
        Returns:
        'true' if it has an extended length field.

      • getExtendedLength

        public long getExtendedLength()
        Get the extended length of the frame.
        Returns:
        the extended length is such a field is present in this frame; 0 otherwise

      • setLength

        public void setLength​(long length)

      • getMaskingKey

        public byte[] getMaskingKey()
        Masking key is an optional field of the websocket protocol. If present, it is 4 byte long.
        Returns:
        null if the frame is not masked; otherwise, the masking key in a fresh new 4 byte array

      • getPayload

        public byte[] getPayload​(boolean unmaskIfNeeded)
        The payload (= 'real' data) of this frame.
        Parameters:
        unmaskIfNeeded - if 'true' and MASK is 1 then it returns the unmasked payload; otherwise, the payload is returned directly
        Returns:
        the payload in a fresh new array

      • getPayloadAsString

        public String getPayloadAsString​(boolean unmaskIfNeeded)

      • getPayloadLength

        public long getPayloadLength()
        Gets the payload length.
        Returns:
        the payload length.

      • append

        public void append​(RawFrame f)
        Appends the payload of a frame into the current frame.
        Parameters:
        f - the frame to gets the payload from.