Class WebSocketServer

java.lang.Object
org.java_websocket.WebSocketAdapter
org.java_websocket.AbstractWebSocket
org.java_websocket.server.WebSocketServer
All Implemented Interfaces:
Runnable, WebSocketListener
public abstract class WebSocketServer extends AbstractWebSocket implements Runnable
WebSocketServer is an abstract class that only takes care of the HTTP handshake portion of WebSockets. It's up to a subclass to add functionality/purpose to the server.

  • Field Details

    • AVAILABLE_PROCESSORS

      private static final int AVAILABLE_PROCESSORS

    • log

      private final org.slf4j.Logger log
      Logger instance
      Since:
      1.4.0

    • connections

      private final Collection<WebSocket> connections
      Holds the list of active WebSocket connections. "Active" means WebSocket handshake is complete and socket can be written to, or read from.

    • address

      private final InetSocketAddress address
      The port number that this WebSocket server should listen on. Default is WebSocketImpl.DEFAULT_PORT.

    • server

      private ServerSocketChannel server
      The socket channel for this WebSocket server.

    • selector

      private Selector selector
      The 'Selector' used to get event keys from the underlying socket.

    • drafts

      private List<Draft> drafts
      The Draft of the WebSocket protocol the Server is adhering to.

    • selectorthread

      private Thread selectorthread

    • isclosed

      private final AtomicBoolean isclosed

    • decoders

      protected List<WebSocketServer.WebSocketWorker> decoders

    • iqueue

      private List<WebSocketImpl> iqueue

    • buffers

      private BlockingQueue<ByteBuffer> buffers

    • queueinvokes

      private int queueinvokes

    • queuesize

      private final AtomicInteger queuesize

    • wsf

      private WebSocketServerFactory wsf

    • maxPendingConnections

      private int maxPendingConnections
      Attribute which allows you to configure the socket "backlog" parameter which determines how many client connections can be queued.
      Since:
      1.5.0

  • Constructor Details

    • WebSocketServer

      public WebSocketServer()
      Creates a WebSocketServer that will attempt to listen on port WebSocketImpl.DEFAULT_PORT.
      See Also:

    • WebSocketServer

      public WebSocketServer(InetSocketAddress address)
      Creates a WebSocketServer that will attempt to bind/listen on the given address.
      Parameters:
      address - The address to listen to
      See Also:

    • WebSocketServer

      public WebSocketServer(InetSocketAddress address, int decodercount)
      Parameters:
      address - The address (host:port) this server should listen on.
      decodercount - The number of WebSocketServer.WebSocketWorkers that will be used to process the incoming network data. By default this will be Runtime.getRuntime().availableProcessors()
      See Also:

    • WebSocketServer

      public WebSocketServer(InetSocketAddress address, List<Draft> drafts)
      Parameters:
      address - The address (host:port) this server should listen on.
      drafts - The versions of the WebSocket protocol that this server instance should comply to. Clients that use an other protocol version will be rejected.
      See Also:

    • WebSocketServer

      public WebSocketServer(InetSocketAddress address, int decodercount, List<Draft> drafts)
      Parameters:
      address - The address (host:port) this server should listen on.
      decodercount - The number of WebSocketServer.WebSocketWorkers that will be used to process the incoming network data. By default this will be Runtime.getRuntime().availableProcessors()
      drafts - The versions of the WebSocket protocol that this server instance should comply to. Clients that use an other protocol version will be rejected.
      See Also:

    • WebSocketServer

      public WebSocketServer(ServerSocketChannel existingChannel)
      Parameters:
      existingChannel - An already open and bound server socket channel, which this server will use. For example, it can be System.inheritedChannel() to implement socket activation.

    • WebSocketServer

      public WebSocketServer(InetSocketAddress address, int decodercount, List<Draft> drafts, Collection<WebSocket> connectionscontainer)
      Creates a WebSocketServer that will attempt to bind/listen on the given address, and comply with Draft version draft.
      Parameters:
      address - The address (host:port) this server should listen on.
      decodercount - The number of WebSocketServer.WebSocketWorkers that will be used to process the incoming network data. By default this will be Runtime.getRuntime().availableProcessors()
      drafts - The versions of the WebSocket protocol that this server instance should comply to. Clients that use an other protocol version will be rejected.
      connectionscontainer - Allows to specify a collection that will be used to store the websockets in.
      If you plan to often iterate through the currently connected websockets you may want to use a collection that does not require synchronization like a CopyOnWriteArraySet. In that case make sure that you overload removeConnection(WebSocket) and addConnection(WebSocket).
      By default a HashSet will be used.
      See Also:

  • Method Details

    • checkAddressOfExistingChannel

      private static InetSocketAddress checkAddressOfExistingChannel(ServerSocketChannel existingChannel)

    • start

      public void start()
      Starts the server selectorthread that binds to the currently set port number and listeners for WebSocket connection requests. Creates a fixed thread pool with the size AVAILABLE_PROCESSORS
      May only be called once.

      Alternatively you can call run() directly.

      Throws:
      IllegalStateException - Starting an instance again

    • stop

      public void stop(int timeout) throws InterruptedException
      Throws:
      InterruptedException

    • stop

      public void stop(int timeout, String closeMessage) throws InterruptedException
      Closes all connected clients sockets, then closes the underlying ServerSocketChannel, effectively killing the server socket selectorthread, freeing the port the server was bound to and stops all internal workerthreads.

      If this method is called before the server is started it will never start.

      Parameters:
      timeout - Specifies how many milliseconds the overall close handshaking may take altogether before the connections are closed without proper close handshaking.
      closeMessage - Specifies message for remote client
      Throws:
      InterruptedException - Interrupt

    • stop

      public void stop() throws InterruptedException
      Throws:
      InterruptedException

    • getConnections

      public Collection<WebSocket> getConnections()
      Returns all currently connected clients. This collection does not allow any modification e.g. removing a client.
      Specified by:
      getConnections in class AbstractWebSocket
      Returns:
      A unmodifiable collection of all currently connected clients
      Since:
      1.3.8

    • getAddress

      public InetSocketAddress getAddress()

    • getPort

      public int getPort()
      Gets the port number that this server listens on.
      Returns:
      The port number.

    • setDaemon

      public void setDaemon(boolean daemon)
      Description copied from class: AbstractWebSocket
      Setter for daemon

      Controls whether or not internal threads are spawned in daemon mode

      Overrides:
      setDaemon in class AbstractWebSocket

    • getDraft

      public List<Draft> getDraft()
      Get the list of active drafts
      Returns:
      the available drafts for this server

    • setMaxPendingConnections

      public void setMaxPendingConnections(int numberOfConnections)
      Set the requested maximum number of pending connections on the socket. The exact semantics are implementation specific. The value provided should be greater than 0. If it is less than or equal to 0, then an implementation specific default will be used. This option will be passed as "backlog" parameter to ServerSocket.bind(SocketAddress, int)
      Parameters:
      numberOfConnections - the new number of allowed pending connections
      Since:
      1.5.0

    • getMaxPendingConnections

      public int getMaxPendingConnections()
      Returns the currently configured maximum number of pending connections.
      Returns:
      the maximum number of pending connections
      Since:
      1.5.0
      See Also:

    • run

      public void run()
      Specified by:
      run in interface Runnable

    • doAdditionalRead

      private void doAdditionalRead() throws InterruptedException, IOException
      Do an additional read
      Throws:
      InterruptedException - thrown by taking a buffer
      IOException - if an error happened during read

    • doAccept

      private void doAccept(SelectionKey key, Iterator<SelectionKey> i) throws IOException, InterruptedException
      Execute a accept operation
      Parameters:
      key - the selectionkey to read off
      i - the iterator for the selection keys
      Throws:
      InterruptedException - thrown by taking a buffer
      IOException - if an error happened during accept

    • doRead

      private boolean doRead(SelectionKey key, Iterator<SelectionKey> i) throws InterruptedException, WrappedIOException
      Execute a read operation
      Parameters:
      key - the selectionkey to read off
      i - the iterator for the selection keys
      Returns:
      true, if the read was successful, or false if there was an error
      Throws:
      InterruptedException - thrown by taking a buffer
      IOException - if an error happened during read
      WrappedIOException

    • doWrite

      private void doWrite(SelectionKey key) throws WrappedIOException
      Execute a write operation
      Parameters:
      key - the selectionkey to write on
      Throws:
      IOException - if an error happened during batch
      WrappedIOException

    • doSetupSelectorAndServerThread

      private boolean doSetupSelectorAndServerThread()
      Setup the selector thread as well as basic server settings
      Returns:
      true, if everything was successful, false if some error happened

    • doEnsureSingleThread

      private boolean doEnsureSingleThread()
      The websocket server can only be started once
      Returns:
      true, if the server can be started, false if already a thread is running

    • doServerShutdown

      private void doServerShutdown()
      Clean up everything after a shutdown

    • allocateBuffers

      protected void allocateBuffers(WebSocket c) throws InterruptedException
      Throws:
      InterruptedException

    • releaseBuffers

      protected void releaseBuffers(WebSocket c) throws InterruptedException
      Throws:
      InterruptedException

    • createBuffer

      public ByteBuffer createBuffer()

    • queue

      protected void queue(WebSocketImpl ws) throws InterruptedException
      Throws:
      InterruptedException

    • takeBuffer

      private ByteBuffer takeBuffer() throws InterruptedException
      Throws:
      InterruptedException

    • pushBuffer

      private void pushBuffer(ByteBuffer buf) throws InterruptedException
      Throws:
      InterruptedException

    • handleIOException

      private void handleIOException(SelectionKey key, WebSocket conn, IOException ex)

    • handleFatal

      private void handleFatal(WebSocket conn, Exception e)

    • onWebsocketMessage

      public final void onWebsocketMessage(WebSocket conn, String message)
      Description copied from interface: WebSocketListener
      Called when an entire text frame has been received. Do whatever you want here...
      Specified by:
      onWebsocketMessage in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      message - The UTF-8 decoded message that was received.

    • onWebsocketMessage

      public final void onWebsocketMessage(WebSocket conn, ByteBuffer blob)
      Description copied from interface: WebSocketListener
      Called when an entire binary frame has been received. Do whatever you want here...
      Specified by:
      onWebsocketMessage in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      blob - The binary message that was received.

    • onWebsocketOpen

      public final void onWebsocketOpen(WebSocket conn, Handshakedata handshake)
      Description copied from interface: WebSocketListener
      Called after onHandshakeReceived returns true. Indicates that a complete WebSocket connection has been established, and we are ready to send/receive data.
      Specified by:
      onWebsocketOpen in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      handshake - The handshake of the websocket instance

    • onWebsocketClose

      public final void onWebsocketClose(WebSocket conn, int code, String reason, boolean remote)
      Description copied from interface: WebSocketListener
      Called after WebSocket#close is explicity called, or when the other end of the WebSocket connection is closed.
      Specified by:
      onWebsocketClose in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      code - The codes can be looked up here: CloseFrame
      reason - Additional information string
      remote - Returns whether or not the closing of the connection was initiated by the remote host.

    • removeConnection

      protected boolean removeConnection(WebSocket ws)
      This method performs remove operations on the connection and therefore also gives control over whether the operation shall be synchronized

      WebSocketServer(InetSocketAddress, int, List, Collection) allows to specify a collection which will be used to store current connections in.
      Depending on the type on the connection, modifications of that collection may have to be synchronized.

      Parameters:
      ws - The Websocket connection which should be removed
      Returns:
      Removing connection successful

    • addConnection

      protected boolean addConnection(WebSocket ws)
      Parameters:
      ws - the Websocket connection which should be added
      Returns:
      Adding connection successful
      See Also:

    • onWebsocketError

      public final void onWebsocketError(WebSocket conn, Exception ex)
      Description copied from interface: WebSocketListener
      Called if an exception worth noting occurred. If an error causes the connection to fail onClose will be called additionally afterwards.
      Specified by:
      onWebsocketError in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      ex - The exception that occurred.
      Might be null if the exception is not related to any specific connection. For example if the server port could not be bound.

    • onWriteDemand

      public final void onWriteDemand(WebSocket w)
      Description copied from interface: WebSocketListener
      This method is used to inform the selector thread that there is data queued to be written to the socket.
      Specified by:
      onWriteDemand in interface WebSocketListener
      Parameters:
      w - The WebSocket instance this event is occurring on.

    • onWebsocketCloseInitiated

      public void onWebsocketCloseInitiated(WebSocket conn, int code, String reason)
      Description copied from interface: WebSocketListener
      send when this peer sends a close handshake
      Specified by:
      onWebsocketCloseInitiated in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      code - The codes can be looked up here: CloseFrame
      reason - Additional information string

    • onWebsocketClosing

      public void onWebsocketClosing(WebSocket conn, int code, String reason, boolean remote)
      Description copied from interface: WebSocketListener
      Called as soon as no further frames are accepted
      Specified by:
      onWebsocketClosing in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      code - The codes can be looked up here: CloseFrame
      reason - Additional information string
      remote - Returns whether or not the closing of the connection was initiated by the remote host.

    • onCloseInitiated

      public void onCloseInitiated(WebSocket conn, int code, String reason)

    • onClosing

      public void onClosing(WebSocket conn, int code, String reason, boolean remote)

    • setWebSocketFactory

      public final void setWebSocketFactory(WebSocketServerFactory wsf)

    • getWebSocketFactory

      public final WebSocketFactory getWebSocketFactory()

    • onConnect

      protected boolean onConnect(SelectionKey key)
      Returns whether a new connection shall be accepted or not.
      Therefore method is well suited to implement some kind of connection limitation.
      Parameters:
      key - the SelectionKey for the new connection
      Returns:
      Can this new connection be accepted
      See Also:

    • getSocket

      private Socket getSocket(WebSocket conn)
      Getter to return the socket used by this specific connection
      Parameters:
      conn - The specific connection
      Returns:
      The socket used by this connection

    • getLocalSocketAddress

      public InetSocketAddress getLocalSocketAddress(WebSocket conn)
      Specified by:
      getLocalSocketAddress in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      Returns:
      Returns the address of the endpoint this socket is bound to.
      See Also:

    • getRemoteSocketAddress

      public InetSocketAddress getRemoteSocketAddress(WebSocket conn)
      Specified by:
      getRemoteSocketAddress in interface WebSocketListener
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      Returns:
      Returns the address of the endpoint this socket is connected to, ornull if it is unconnected.
      See Also:

    • onOpen

      public abstract void onOpen(WebSocket conn, ClientHandshake handshake)
      Called after an opening handshake has been performed and the given websocket is ready to be written on.
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      handshake - The handshake of the websocket instance

    • onClose

      public abstract void onClose(WebSocket conn, int code, String reason, boolean remote)
      Called after the websocket connection has been closed.
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      code - The codes can be looked up here: CloseFrame
      reason - Additional information string
      remote - Returns whether or not the closing of the connection was initiated by the remote host.

    • onMessage

      public abstract void onMessage(WebSocket conn, String message)
      Callback for string messages received from the remote host
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      message - The UTF-8 decoded message that was received.
      See Also:

    • onError

      public abstract void onError(WebSocket conn, Exception ex)
      Called when errors occurs. If an error causes the websocket connection to fail onClose(WebSocket, int, String, boolean) will be called additionally.
      This method will be called primarily because of IO or protocol errors.
      If the given exception is an RuntimeException that probably means that you encountered a bug.
      Parameters:
      conn - Can be null if there error does not belong to one specific websocket. For example if the servers port could not be bound.
      ex - The exception causing this error

    • onStart

      public abstract void onStart()
      Called when the server started up successfully.

      If any error occurred, onError is called instead.

    • onMessage

      public void onMessage(WebSocket conn, ByteBuffer message)
      Callback for binary messages received from the remote host
      Parameters:
      conn - The WebSocket instance this event is occurring on.
      message - The binary message that was received.
      See Also:

    • broadcast

      public void broadcast(String text)
      Send a text to all connected endpoints
      Parameters:
      text - the text to send to the endpoints

    • broadcast

      public void broadcast(byte[] data)
      Send a byte array to all connected endpoints
      Parameters:
      data - the data to send to the endpoints

    • broadcast

      public void broadcast(ByteBuffer data)
      Send a ByteBuffer to all connected endpoints
      Parameters:
      data - the data to send to the endpoints

    • broadcast

      public void broadcast(byte[] data, Collection<WebSocket> clients)
      Send a byte array to a specific collection of websocket connections
      Parameters:
      data - the data to send to the endpoints
      clients - a collection of endpoints to whom the text has to be send

    • broadcast

      public void broadcast(ByteBuffer data, Collection<WebSocket> clients)
      Send a ByteBuffer to a specific collection of websocket connections
      Parameters:
      data - the data to send to the endpoints
      clients - a collection of endpoints to whom the text has to be send

    • broadcast

      public void broadcast(String text, Collection<WebSocket> clients)
      Send a text to a specific collection of websocket connections
      Parameters:
      text - the text to send to the endpoints
      clients - a collection of endpoints to whom the text has to be send

    • doBroadcast

      private void doBroadcast(Object data, Collection<WebSocket> clients)
      Private method to cache all the frames to improve memory footprint and conversion time
      Parameters:
      data - the data to broadcast
      clients - the clients to send the message to

    • fillFrames

      private void fillFrames(Draft draft, Map<Draft, List<Framedata>> draftFrames, String strData, ByteBuffer byteData)
      Fills the draftFrames with new data for the broadcast
      Parameters:
      draft - The draft to use
      draftFrames - The list of frames per draft to fill
      strData - the string data, can be null
      byteData - the byte buffer data, can be null