Class WsFrameBase

java.lang.Object
org.apache.tomcat.websocket.WsFrameBase
Direct Known Subclasses:
WsFrameClient, WsFrameServer
public abstract class WsFrameBase extends Object
Takes the ServletInputStream, processes the WebSocket frames it contains and extracts the messages. WebSocket Pings received will be responded to automatically without any action required by the application.

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    protected static enum 
    WsFrameBase.ReadState
    WAITING - not suspended Server case: waiting for a notification that data is ready to be read from the socket, the socket is registered to the poller Client case: data has been read from the socket and is waiting for data to be processed PROCESSING - not suspended Server case: reading from the socket and processing the data Client case: processing the data if such has already been read and more data will be read from the socket SUSPENDING_WAIT - suspended, a call to suspend() was made while in WAITING state.

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    protected final ByteBuffer
    inputBuffer
    The input buffer for reading data.
    protected final WsSession
    wsSession
    The WebSocket session for this frame.

  • Constructor Summary

    Constructors
    Constructor
    Description
    WsFrameBase(WsSession wsSession, Transformation transformation)
    Constructs a new WsFrameBase.

  • Method Summary

    Modifier and Type
    Method
    Description
    protected static long
    byteArrayToLong(byte[] b, int start, int len)
    Converts a byte array segment to a long value.
    protected void
    changeReadState(WsFrameBase.ReadState newState)
    Changes the read state to the new state.
    protected boolean
    changeReadState(WsFrameBase.ReadState oldState, WsFrameBase.ReadState newState)
    Atomically changes the read state if it matches the expected old state.
    protected abstract Log
    getLog()
    Returns the log instance for this frame.
    protected WsFrameBase.ReadState
    getReadState()
    Returns the current read state.
    protected Transformation
    getTransformation()
    Returns the transformation applied to this frame.
    protected abstract boolean
    isMasked()
    Returns whether frames from this peer must be masked.
    protected boolean
    isOpen()
    Returns whether the connection is open.
    protected boolean
    isSuspended()
    Returns whether this frame is currently suspended.
    protected void
    processInputBuffer()
    Processes the input buffer, reading and handling WebSocket frames.
    void
    resume()
    Resumes processing of this frame after suspension.
    protected abstract void
    resumeProcessing()
    This method will be invoked when the read operation is resumed.
    protected void
    sendMessageBinary(ByteBuffer msg, boolean last)
    Sends a binary message to the remote endpoint.
    protected void
    sendMessageText(boolean last)
    Sends a text message to the remote endpoint.
    void
    suspend()
    Suspends processing of this frame.
    protected void
    updateStats(long payloadLength)
    Hook for updating server side statistics.

    Methods inherited from class Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Field Details

    • wsSession

      protected final WsSession wsSession
      The WebSocket session for this frame.

    • inputBuffer

      protected final ByteBuffer inputBuffer
      The input buffer for reading data.

  • Constructor Details

    • WsFrameBase

      public WsFrameBase(WsSession wsSession, Transformation transformation)
      Constructs a new WsFrameBase.
      Parameters:
      wsSession - The WebSocket session
      transformation - The transformation to apply

  • Method Details

    • processInputBuffer

      protected void processInputBuffer() throws IOException
      Processes the input buffer, reading and handling WebSocket frames.
      Throws:
      IOException - If an I/O error occurs

    • isMasked

      protected abstract boolean isMasked()
      Returns whether frames from this peer must be masked.
      Returns:
      true if frames must be masked

    • getLog

      protected abstract Log getLog()
      Returns the log instance for this frame.
      Returns:
      the log instance

    • updateStats

      protected void updateStats(long payloadLength)
      Hook for updating server side statistics. Called on every frame received.
      Parameters:
      payloadLength - Size of message payload

    • sendMessageText

      protected void sendMessageText(boolean last) throws WsIOException
      Sends a text message to the remote endpoint.
      Parameters:
      last - Whether this is the last fragment of the message
      Throws:
      WsIOException - If a WebSocket I/O error occurs

    • sendMessageBinary

      protected void sendMessageBinary(ByteBuffer msg, boolean last) throws WsIOException
      Sends a binary message to the remote endpoint.
      Parameters:
      msg - The message data
      last - Whether this is the last fragment of the message
      Throws:
      WsIOException - If a WebSocket I/O error occurs

    • byteArrayToLong

      protected static long byteArrayToLong(byte[] b, int start, int len) throws IOException
      Converts a byte array segment to a long value.
      Parameters:
      b - The byte array
      start - The start index
      len - The length
      Returns:
      the long value
      Throws:
      IOException - If the length exceeds 8 bytes

    • isOpen

      protected boolean isOpen()
      Returns whether the connection is open.
      Returns:
      true if open

    • getTransformation

      protected Transformation getTransformation()
      Returns the transformation applied to this frame.
      Returns:
      the transformation

    • suspend

      public void suspend()
      Suspends processing of this frame.

    • resume

      public void resume()
      Resumes processing of this frame after suspension.

    • isSuspended

      protected boolean isSuspended()
      Returns whether this frame is currently suspended.
      Returns:
      true if suspended

    • getReadState

      protected WsFrameBase.ReadState getReadState()
      Returns the current read state.
      Returns:
      the read state

    • changeReadState

      protected void changeReadState(WsFrameBase.ReadState newState)
      Changes the read state to the new state.
      Parameters:
      newState - The new read state

    • changeReadState

      protected boolean changeReadState(WsFrameBase.ReadState oldState, WsFrameBase.ReadState newState)
      Atomically changes the read state if it matches the expected old state.
      Parameters:
      oldState - The expected old state
      newState - The new state
      Returns:
      true if the state was changed

    • resumeProcessing

      protected abstract void resumeProcessing()
      This method will be invoked when the read operation is resumed. Since suspend of the read operation can be invoked at any time, when implementing this method one should consider that there might still be data remaining into the internal buffers that needs to be processed before reading again from the socket.