Package com.neovisionaries.ws.client

Class WebSocket

java.lang.Object
com.neovisionaries.ws.client.WebSocket
public class WebSocket extends Object
WebSocket.

Create WebSocketFactory

WebSocketFactory is a factory class that creates WebSocket instances. The first step is to create a WebSocketFactory instance. 

 // Create a WebSocketFactory instance.
 WebSocketFactory factory = new WebSocketFactory();

By default, WebSocketFactory uses SocketFactory.getDefault() for non-secure WebSocket connections (ws:) and SSLSocketFactory .getDefault() for secure WebSocket connections ( wss:). You can change this default behavior by using WebSocketFactory.setSocketFactory method, WebSocketFactory.setSSLSocketFactory method and WebSocketFactory.setSSLContext method. Note that you don't have to call a setSSL* method at all if you use the default SSL configuration. Also note that calling setSSLSocketFactory method has no meaning if you have called setSSLContext method. See the description of WebSocketFactory.createSocket(URI) method for details.

The following is an example to set a custom SSL context to a WebSocketFactory instance. (Again, you don't have to call a setSSL* method if you use the default SSL configuration.) 

 // Create a custom SSL context.
 SSLContext context = NaiveSSLContext.getInstance("TLS");

 // Set the custom SSL context.
 factory.setSSLContext(context);

 // Disable manual hostname verification for NaiveSSLContext.
 //
 // Manual hostname verification has been enabled since the
 // version 2.1. Because the verification is executed manually
 // after Socket.connect(SocketAddress, int) succeeds, the
 // hostname verification is always executed even if you has
 // passed an SSLContext which naively accepts any server
 // certificate. However, this behavior is not desirable in
 // some cases and you may want to disable the hostname
 // verification. You can disable the hostname verification
 // by calling WebSocketFactory.setVerifyHostname(false).
 factory.setVerifyHostname(false);

NaiveSSLContext used in the above example is a factory class to create an SSLContext which naively accepts all certificates without verification. It's enough for testing purposes. When you see an error message "unable to find valid certificate path to requested target" while testing, try NaiveSSLContext.

HTTP Proxy

If a WebSocket endpoint needs to be accessed via an HTTP proxy, information about the proxy server has to be set to a WebSocketFactory instance before creating a WebSocket instance. Proxy settings are represented by ProxySettings class. A WebSocketFactory instance has an associated ProxySettings instance and it can be obtained by calling WebSocketFactory.getProxySettings() method. 

 // Get the associated ProxySettings instance.
 ProxySettings settings = factory.getProxySettings();

ProxySettings class has methods to set information about a proxy server such as setHost method and setPort method. The following is an example to set a secure (https) proxy server. 

 // Set a proxy server.
 settings.setServer("https://proxy.example.com");

If credentials are required for authentication at a proxy server, setId method and setPassword method, or setCredentials method can be used to set the credentials. Note that, however, the current implementation supports only Basic Authentication. 

 // Set credentials for authentication at a proxy server.
 settings.setCredentials(id, password);

Create WebSocket

WebSocket class represents a WebSocket. Its instances are created by calling one of createSocket methods of a WebSocketFactory instance. Below is the simplest example to create a WebSocket instance. 

 // Create a WebSocket. The scheme part can be one of the following:
 // 'ws', 'wss', 'http' and 'https' (case-insensitive). The user info
 // part, if any, is interpreted as expected. If a raw socket failed
 // to be created, an IOException is thrown.
 WebSocket ws = new WebSocketFactory()
     .createWebSocket("ws://localhost/endpoint");

There are two ways to set a timeout value for socket connection. The first way is to call setConnectionTimeout(int timeout) method of WebSocketFactory. 

 // Create a WebSocket factory and set 5000 milliseconds as a timeout
 // value for socket connection.
 WebSocketFactory factory = new WebSocketFactory().setConnectionTimeout(5000);

 // Create a WebSocket. The timeout value set above is used.
 WebSocket ws = factory.createWebSocket("ws://localhost/endpoint");

The other way is to give a timeout value to a createSocket method. 

 // Create a WebSocket factory. The timeout value remains 0.
 WebSocketFactory factory = new WebSocketFactory();

 // Create a WebSocket with a socket connection timeout value.
 WebSocket ws = factory.createWebSocket("ws://localhost/endpoint", 5000);

The timeout value is passed to connect(SocketAddress, int) method of Socket.

Register Listener

After creating a WebSocket instance, you should call addListener(WebSocketListener) method to register a WebSocketListener that receives WebSocket events. WebSocketAdapter is an empty implementation of WebSocketListener interface. 

 // Register a listener to receive WebSocket events.
 ws.addListener(new WebSocketAdapter() {
     @Override
     public void onTextMessage(WebSocket websocket, String message) throws Exception {
         // Received a text message.
         ......
     }
 });

The table below is the list of callback methods defined in WebSocketListener interface.

WebSocketListener methods
Method Description
handleCallbackError Called when an onXxx() method threw a Throwable.
onBinaryFrame Called when a binary frame was received.
onBinaryMessage Called when a binary message was received.
onCloseFrame Called when a close frame was received.
onConnected Called after the opening handshake succeeded.
onConnectError Called when connectAsynchronously() failed.
onContinuationFrame Called when a continuation frame was received.
onDisconnected Called after a WebSocket connection was closed.
onError Called when an error occurred.
onFrame Called when a frame was received.
onFrameError Called when a frame failed to be read.
onFrameSent Called when a frame was sent.
onFrameUnsent Called when a frame was not sent.
onMessageDecompressionError Called when a message failed to be decompressed.
onMessageError Called when a message failed to be constructed.
onPingFrame Called when a ping frame was received.
onPongFrame Called when a pong frame was received.
onSendError Called when an error occurred on sending a frame.
onSendingFrame Called before a frame is sent.
onSendingHandshake Called before an opening handshake is sent.
onStateChanged Called when the state of WebSocket changed.
onTextFrame Called when a text frame was received.
onTextMessage Called when a text message was received.
onTextMessageError Called when a text message failed to be constructed.
onThreadCreated Called after a thread was created.
onThreadStarted Called at the beginning of a thread's run() method.
onThreadStopping Called at the end of a thread's run() method.
onUnexpectedError Called when an uncaught throwable was detected.

Configure WebSocket

Before starting a WebSocket opening handshake with the server, you can configure the WebSocket instance by using the following methods.

Methods for Configuration
METHOD DESCRIPTION
addProtocol Adds an element to Sec-WebSocket-Protocol
addExtension Adds an element to Sec-WebSocket-Extensions
addHeader Adds an arbitrary HTTP header.
setUserInfo Adds Authorization header for Basic Authentication.
getSocket Gets the underlying Socket instance to configure it. Note that this may return null since version 2.9. Consider using getConnectedSocket() as necessary.
getConnectedSocket Establishes and gets the underlying Socket instance to configure it. Available since version 2.9.
setExtended Disables validity checks on RSV1/RSV2/RSV3 and opcode.
setFrameQueueSize Set the size of the frame queue for congestion control.
setMaxPayloadSize Set the maximum payload size.
setMissingCloseFrameAllowed Set whether to allow the server to close the connection without sending a close frame.

Connect To Server

By calling connect() method, connection to the server is established and a WebSocket opening handshake is performed synchronously. If an error occurred during the handshake, a WebSocketException would be thrown. Instead, when the handshake succeeds, the connect() implementation creates threads and starts them to read and write WebSocket frames asynchronously. 

 try
 {
     // Connect to the server and perform an opening handshake.
     // This method blocks until the opening handshake is finished.
     ws.connect();
 }
 catch (OpeningHandshakeException e)
 {
     // A violation against the WebSocket protocol was detected
     // during the opening handshake.
 }
 catch (HostnameUnverifiedException e)
 {
     // The certificate of the peer does not match the expected hostname.
 }
 catch (WebSocketException e)
 {
     // Failed to establish a WebSocket connection.
 }

In some cases, connect() method throws OpeningHandshakeException which is a subclass of WebSocketException (since version 1.19). OpeningHandshakeException provides additional methods such as getStatusLine(), getHeaders() and getBody() to access the response from a server. The following snippet is an example to print information that the exception holds. 

 catch (OpeningHandshakeException e)
 {
     // Status line.
     StatusLine sl = e.getStatusLine();
     System.out.println("=== Status Line ===");
     System.out.format("HTTP Version  = %s\n", sl.getHttpVersion());
     System.out.format("Status Code   = %d\n", sl.getStatusCode());
     System.out.format("Reason Phrase = %s\n", sl.getReasonPhrase());

     // HTTP headers.
     Map<String, List<String>> headers = e.getHeaders();
     System.out.println("=== HTTP Headers ===");
     for (Map.Entry<String, List<String>> entry : headers.entrySet())
     {
         // Header name.
         String name = entry.getKey();

         // Values of the header.
         List<String> values = entry.getValue();

         if (values == null || values.size() == 0)
         {
             // Print the name only.
             System.out.println(name);
             continue;
         }

         for (String value : values)
         {
             // Print the name and the value.
             System.out.format("%s: %s\n", name, value);
         }
     }
 }

Also, connect() method throws HostnameUnverifiedException which is a subclass of WebSocketException (since version 2.1) when the certificate of the peer does not match the expected hostname.

Connect To Server Asynchronously

The simplest way to call connect() method asynchronously is to use connectAsynchronously() method. The implementation of the method creates a thread and calls connect() method in the thread. When the connect() call failed, onConnectError() of WebSocketListener would be called. Note that onConnectError() is called only when connectAsynchronously() was used and the connect() call executed in the background thread failed. Neither direct synchronous connect() nor connect(ExecutorService) (described below) will trigger the callback method. 

 // Connect to the server asynchronously.
 ws.connectAsynchronously();

Another way to call connect() method asynchronously is to use connect(ExecutorService) method. The method performs a WebSocket opening handshake asynchronously using the given ExecutorService. 

 // Prepare an ExecutorService.
 ExecutorService es = Executors.newSingleThreadExecutor();

 // Connect to the server asynchronously.
 Future<WebSocket> future = ws.connect(es);

 try
 {
     // Wait for the opening handshake to complete.
     future.get();
 }
 catch (ExecutionException e)
 {
     if (e.getCause() instanceof WebSocketException)
     {
         ......
     }
 }

The implementation of connect(ExecutorService) method creates a Callable<WebSocket> instance by calling connectable() method and passes the instance to submit(Callable) method of the given ExecutorService. What the implementation of call() method of the Callable instance does is just to call the synchronous connect().

Send Frames

WebSocket frames can be sent by sendFrame(WebSocketFrame) method. Other sendXxx methods such as sendText(String) are aliases of sendFrame method. All of the sendXxx methods work asynchronously. However, under some conditions, sendXxx methods may block. See Congestion Control for details.

Below are some examples of sendXxx methods. Note that in normal cases, you don't have to call sendClose() method and sendPong() (or their variants) explicitly because they are called automatically when appropriate. 

 // Send a text frame.
 ws.sendText("Hello.");

 // Send a binary frame.
 byte[] binary = ......;
 ws.sendBinary(binary);

 // Send a ping frame.
 ws.sendPing("Are you there?");

If you want to send fragmented frames, you have to know the details of the specification (5.4. Fragmentation). Below is an example to send a text message ("How are you?") which consists of 3 fragmented frames. 

 // The first frame must be either a text frame or a binary frame.
 // And its FIN bit must be cleared.
 WebSocketFrame firstFrame = WebSocketFrame
     .createTextFrame("How ")
     .setFin(false);

 // Subsequent frames must be continuation frames. The FIN bit of
 // all continuation frames except the last one must be cleared.
 // Note that the FIN bit of frames returned from
 // WebSocketFrame.createContinuationFrame methods is cleared, so
 // the example below does not clear the FIN bit explicitly.
 WebSocketFrame secondFrame = WebSocketFrame
     .createContinuationFrame("are ");

 // The last frame must be a continuation frame with the FIN bit set.
 // Note that the FIN bit of frames returned from
 // WebSocketFrame.createContinuationFrame methods is cleared, so
 // the FIN bit of the last frame must be set explicitly.
 WebSocketFrame lastFrame = WebSocketFrame
     .createContinuationFrame("you?")
     .setFin(true);

 // Send a text message which consists of 3 frames.
 ws.sendFrame(firstFrame)
   .sendFrame(secondFrame)
   .sendFrame(lastFrame);

Alternatively, the same as above can be done like this. 

 // Send a text message which consists of 3 frames.
 ws.sendText("How ", false)
   .sendContinuation("are ")
   .sendContinuation("you?", true);

Send Ping/Pong Frames Periodically

You can send ping frames periodically by calling setPingInterval method with an interval in milliseconds between ping frames. This method can be called both before and after connect() method. Passing zero stops the periodical sending. 

 // Send a ping per 60 seconds.
 ws.setPingInterval(60 * 1000);

 // Stop the periodical sending.
 ws.setPingInterval(0);

Likewise, you can send pong frames periodically by calling setPongInterval method. "A Pong frame MAY be sent unsolicited." (RFC 6455, 5.5.3. Pong)

You can customize payload of ping/pong frames that are sent automatically by using setPingPayloadGenerator(PayloadGenerator) and setPongPayloadGenerator(PayloadGenerator) methods. Both methods take an instance of PayloadGenerator interface. The following is an example to use the string representation of the current date as payload of ping frames. 

 ws.setPingPayloadGenerator(new PayloadGenerator () {
     @Override
     public byte[] generate() {
         // The string representation of the current date.
         return new Date().toString().getBytes();
     }
 });

Note that the maximum payload length of control frames (e.g. ping frames) is 125. Therefore, the length of a byte array returned from generate() method must not exceed 125.

You can change the names of the Timers that send ping/pong frames periodically by using setPingSenderName(String) and setPongSenderName(String) methods. 

 // Change the Timers' names.
 ws.setPingSenderName("PING_SENDER");
 ws.setPongSenderName("PONG_SENDER");

Auto Flush

By default, a frame is automatically flushed to the server immediately after sendFrame method is executed. This automatic flush can be disabled by calling setAutoFlush (false). 

 // Disable auto-flush.
 ws.setAutoFlush(false);

To flush frames manually, call flush() method. Note that this method works asynchronously. 

 // Flush frames to the server manually.
 ws.flush();

Congestion Control

sendXxx methods queue a WebSocketFrame instance to the internal queue. By default, no upper limit is imposed on the queue size, so sendXxx methods do not block. However, this behavior may cause a problem if your WebSocket client application sends too many WebSocket frames in a short time for the WebSocket server to process. In such a case, you may want sendXxx methods to block when many frames are queued.

You can set an upper limit on the internal queue by calling setFrameQueueSize(int) method. As a result, if the number of frames in the queue has reached the upper limit when a sendXxx method is called, the method blocks until the queue gets spaces. The code snippet below is an example to set 5 as the upper limit of the internal frame queue. 

 // Set 5 as the frame queue size.
 ws.setFrameQueueSize(5);

Note that under some conditions, even if the queue is full, sendXxx methods do not block. For example, in the case where the thread to send frames (WritingThread) is going to stop or has already stopped. In addition, method calls to send a control frame (e.g. sendClose() and sendPing()) do not block.

Maximum Payload Size

You can set an upper limit on the payload size of WebSocket frames by calling setMaxPayloadSize(int) method with a positive value. Text, binary and continuation frames whose payload size is bigger than the maximum payload size you have set will be split into multiple frames. 

 // Set 1024 as the maximum payload size.
 ws.setMaxPayloadSize(1024);

Control frames (close, ping and pong frames) are never split as per the specification.

If permessage-deflate extension is enabled and if the payload size of a WebSocket frame after compression does not exceed the maximum payload size, the WebSocket frame is not split even if the payload size before compression execeeds the maximum payload size.

Compression

The permessage-deflate extension (RFC 7692) has been supported since the version 1.17. To enable the extension, call addExtension method with "permessage-deflate". 

 // Enable "permessage-deflate" extension (RFC 7692).
 ws.addExtension(WebSocketExtension.PERMESSAGE_DEFLATE);

Missing Close Frame

Some server implementations close a WebSocket connection without sending a close frame to a client in some cases. Strictly speaking, this is a violation against the specification (RFC 6455). However, this library has allowed the behavior by default since the version 1.29. Even if the end of the input stream of a WebSocket connection were reached without a close frame being received, it would trigger neither onError() method nor onFrameError() method of WebSocketListener. If you want to make a WebSocket instance report an error in the case, pass false to setMissingCloseFrameAllowed(boolean) method. 

 // Make this library report an error when the end of the input stream
 // of the WebSocket connection is reached before a close frame is read.
 ws.setMissingCloseFrameAllowed(false);

Direct Text Message

When a text message was received, onTextMessage(WebSocket, String) is called. The implementation internally converts the byte array of the text message into a String object before calling the listener method. If you want to receive the byte array directly without the string conversion, call setDirectTextMessage(boolean) with true, and onTextMessage(WebSocket, byte[]) will be called instead. 

 // Receive text messages without string conversion.
 ws.setDirectTextMessage(true);

Disconnect WebSocket

Before a WebSocket is closed, a closing handshake is performed. A closing handshake is started (1) when the server sends a close frame to the client or (2) when the client sends a close frame to the server. You can start a closing handshake by calling disconnect() method (or by sending a close frame manually). 

 // Close the WebSocket connection.
 ws.disconnect();

disconnect() method has some variants. If you want to change the close code and the reason phrase of the close frame that this client will send to the server, use a variant method such as disconnect(int, String). disconnect() method itself is an alias of disconnect(WebSocketCloseCode .NORMAL, null).

Reconnection

connect() method can be called at most only once regardless of whether the method succeeded or failed. If you want to re-connect to the WebSocket endpoint, you have to create a new WebSocket instance again by calling one of createSocket methods of a WebSocketFactory. You may find recreate() method useful if you want to create a new WebSocket instance that has the same settings as the original instance. Note that, however, settings you made on the raw socket of the original WebSocket instance are not copied. 

 // Create a new WebSocket instance and connect to the same endpoint.
 ws = ws.recreate().connect();

There is a variant of recreate() method that takes a timeout value for socket connection. If you want to use a timeout value that is different from the one used when the existing WebSocket instance was created, use recreate(int timeout) method.

Note that you should not trigger reconnection in onError() method because onError() may be called multiple times due to one error. Instead, onDisconnected() is the right place to trigger reconnection.

Also note that the reason I use an expression of "to trigger reconnection" instead of "to call recreate().connect()" is that I myself won't do it synchronously in WebSocketListener callback methods but will just schedule reconnection or will just go to the top of a kind of application loop that repeats to establish a WebSocket connection until it succeeds.

Error Handling

WebSocketListener has some onXxxError() methods such as onFrameError() and onSendError(). Among such methods, onError() is a special one. It is always called before any other onXxxError() is called. For example, in the implementation of run() method of ReadingThread, Throwable is caught and onError() and onUnexpectedError() are called in this order. The following is the implementation. 

 @Override
 public void run()
 {
     try
     {
         main();
     }
     catch (Throwable t)
     {
         // An uncaught throwable was detected in the reading thread.
         WebSocketException cause = new WebSocketException(
             WebSocketError.UNEXPECTED_ERROR_IN_READING_THREAD,
             "An uncaught throwable was detected in the reading thread", t);

         // Notify the listeners.
         ListenerManager manager = mWebSocket.getListenerManager();
         manager.callOnError(cause);
         manager.callOnUnexpectedError(cause);
     }
 }

So, you can handle all error cases in onError() method. However, note that onError() may be called multiple times for one error cause, so don't try to trigger reconnection in onError(). Instead, onDiconnected() is the right place to trigger reconnection.

All onXxxError() methods receive a WebSocketException instance as the second argument (the first argument is a WebSocket instance). The exception class provides getError() method which returns a WebSocketError enum entry. Entries in WebSocketError enum are possible causes of errors that may occur in the implementation of this library. The error causes are so granular that they can make it easy for you to find the root cause when an error occurs.

Throwables thrown by implementations of onXXX() callback methods are passed to handleCallbackError() of WebSocketListener. 

 @Override
 public void handleCallbackError(WebSocket websocket, Throwable cause) throws Exception {
     // Throwables thrown by onXxx() callback methods come here.
 }

Thread Callbacks

Some threads are created internally in the implementation of WebSocket. Known threads are as follows.

Internal Threads
THREAD TYPE DESCRIPTION
READING_THREAD A thread which reads WebSocket frames from the server.
WRITING_THREAD A thread which sends WebSocket frames to the server.
CONNECT_THREAD A thread which calls connect() asynchronously.
FINISH_THREAD A thread which does finalization of a WebSocket instance.

The following callback methods of WebSocketListener are called according to the life cycle of the threads.

Thread Callbacks
METHOD DESCRIPTION
onThreadCreated() Called after a thread was created.
onThreadStarted() Called at the beginning of the thread's run() method.
onThreadStopping() Called at the end of the thread's run() method.

For example, if you want to change the name of the reading thread, implement onThreadCreated() method like below. 

 @Override
 public void onThreadCreated(WebSocket websocket, ThreadType type, Thread thread)
 {
     if (type == ThreadType.READING_THREAD)
     {
         thread.setName("READING_THREAD");
     }
 }
See Also:

  • Field Details

    • DEFAULT_CLOSE_DELAY

      private static final long DEFAULT_CLOSE_DELAY
      See Also:

    • mWebSocketFactory

      private final WebSocketFactory mWebSocketFactory

    • mSocketConnector

      private final SocketConnector mSocketConnector

    • mStateManager

      private final StateManager mStateManager

    • mHandshakeBuilder

      private HandshakeBuilder mHandshakeBuilder

    • mListenerManager

      private final ListenerManager mListenerManager

    • mPingSender

      private final PingSender mPingSender

    • mPongSender

      private final PongSender mPongSender

    • mThreadsLock

      private final Object mThreadsLock

    • mInput

      private WebSocketInputStream mInput

    • mOutput

      private WebSocketOutputStream mOutput

    • mReadingThread

      private ReadingThread mReadingThread

    • mWritingThread

      private WritingThread mWritingThread

    • mServerHeaders

      private Map<String,List<String>> mServerHeaders

    • mAgreedExtensions

      private List<WebSocketExtension> mAgreedExtensions

    • mAgreedProtocol

      private String mAgreedProtocol

    • mExtended

      private boolean mExtended

    • mAutoFlush

      private boolean mAutoFlush

    • mMissingCloseFrameAllowed

      private boolean mMissingCloseFrameAllowed

    • mDirectTextMessage

      private boolean mDirectTextMessage

    • mFrameQueueSize

      private int mFrameQueueSize

    • mMaxPayloadSize

      private int mMaxPayloadSize

    • mOnConnectedCalled

      private boolean mOnConnectedCalled

    • mOnConnectedCalledLock

      private Object mOnConnectedCalledLock

    • mReadingThreadStarted

      private boolean mReadingThreadStarted

    • mWritingThreadStarted

      private boolean mWritingThreadStarted

    • mReadingThreadFinished

      private boolean mReadingThreadFinished

    • mWritingThreadFinished

      private boolean mWritingThreadFinished

    • mServerCloseFrame

      private WebSocketFrame mServerCloseFrame

    • mClientCloseFrame

      private WebSocketFrame mClientCloseFrame

    • mPerMessageCompressionExtension

      private PerMessageCompressionExtension mPerMessageCompressionExtension

  • Constructor Details

  • Method Details

    • recreate

      public WebSocket recreate() throws IOException
      Create a new WebSocket instance that has the same settings as this instance. Note that, however, settings you made on the raw socket are not copied.

      The WebSocketFactory instance that you used to create this WebSocket instance is used again.

      This method calls recreate(int) with the timeout value that was used when this instance was created. If you want to create a socket connection with a different timeout value, use recreate(int) method instead.

      Returns:
      A new WebSocket instance.
      Throws:
      IOException - WebSocketFactory.createSocket(URI) threw an exception.
      Since:
      1.6

    • recreate

      public WebSocket recreate(int timeout) throws IOException
      Create a new WebSocket instance that has the same settings as this instance. Note that, however, settings you made on the raw socket are not copied.

      The WebSocketFactory instance that you used to create this WebSocket instance is used again.

      Parameters:
      timeout - The timeout value in milliseconds for socket timeout. A timeout of zero is interpreted as an infinite timeout.
      Returns:
      A new WebSocket instance.
      Throws:
      IllegalArgumentException - The given timeout value is negative.
      IOException - WebSocketFactory.createSocket(URI) threw an exception.
      Since:
      1.10

    • finalize

      protected void finalize() throws Throwable
      Overrides:
      finalize in class Object
      Throws:
      Throwable

    • getState

      public WebSocketState getState()
      Get the current state of this WebSocket.

      The initial state is CREATED. When connect() is called, the state is changed to CONNECTING, and then to OPEN after a successful opening handshake. The state is changed to CLOSING when a closing handshake is started, and then to CLOSED when the closing handshake finished.

      See the description of WebSocketState for details.

      Returns:
      The current state.
      See Also:

    • isOpen

      public boolean isOpen()
      Check if the current state of this WebSocket is OPEN.
      Returns:
      true if the current state is OPEN.
      Since:
      1.1

    • isInState

      private boolean isInState(WebSocketState state)
      Check if the current state is equal to the specified state.

    • addProtocol

      public WebSocket addProtocol(String protocol)
      Add a value for Sec-WebSocket-Protocol.
      Parameters:
      protocol - A protocol name.
      Returns:
      this object.
      Throws:
      IllegalArgumentException - The protocol name is invalid. A protocol name must be a non-empty string with characters in the range U+0021 to U+007E not including separator characters.

    • removeProtocol

      public WebSocket removeProtocol(String protocol)
      Remove a protocol from Sec-WebSocket-Protocol.
      Parameters:
      protocol - A protocol name. null is silently ignored.
      Returns:
      this object.
      Since:
      1.14

    • clearProtocols

      public WebSocket clearProtocols()
      Remove all protocols from Sec-WebSocket-Protocol.
      Returns:
      this object.
      Since:
      1.14

    • addExtension

      public WebSocket addExtension(WebSocketExtension extension)
      Add a value for Sec-WebSocket-Extension.
      Parameters:
      extension - An extension. null is silently ignored.
      Returns:
      this object.

    • addExtension

      public WebSocket addExtension(String extension)
      Add a value for Sec-WebSocket-Extension. The input string should comply with the format described in 9.1. Negotiating Extensions in RFC 6455.
      Parameters:
      extension - A string that represents a WebSocket extension. If it does not comply with RFC 6455, no value is added to Sec-WebSocket-Extension.
      Returns:
      this object.
      Since:
      1.14

    • removeExtension

      public WebSocket removeExtension(WebSocketExtension extension)
      Remove an extension from Sec-WebSocket-Extension.
      Parameters:
      extension - An extension to remove. null is silently ignored.
      Returns:
      this object.
      Since:
      1.14

    • removeExtensions

      public WebSocket removeExtensions(String name)
      Remove extensions from Sec-WebSocket-Extension by an extension name.
      Parameters:
      name - An extension name. null is silently ignored.
      Returns:
      this object.
      Since:
      1.14

    • clearExtensions

      public WebSocket clearExtensions()
      Remove all extensions from Sec-WebSocket-Extension.
      Returns:
      this object.
      Since:
      1.14

    • addHeader

      public WebSocket addHeader(String name, String value)
      Add a pair of extra HTTP header.
      Parameters:
      name - An HTTP header name. When null or an empty string is given, no header is added.
      value - The value of the HTTP header.
      Returns:
      this object.

    • removeHeaders

      public WebSocket removeHeaders(String name)
      Remove pairs of extra HTTP headers.
      Parameters:
      name - An HTTP header name. null is silently ignored.
      Returns:
      this object.
      Since:
      1.14

    • clearHeaders

      public WebSocket clearHeaders()
      Clear all extra HTTP headers.
      Returns:
      this object.
      Since:
      1.14

    • setUserInfo

      public WebSocket setUserInfo(String userInfo)
      Set the credentials to connect to the WebSocket endpoint.
      Parameters:
      userInfo - The credentials for Basic Authentication. The format should be id:password.
      Returns:
      this object.

    • setUserInfo

      public WebSocket setUserInfo(String id, String password)
      Set the credentials to connect to the WebSocket endpoint.
      Parameters:
      id - The ID.
      password - The password.
      Returns:
      this object.

    • clearUserInfo

      public WebSocket clearUserInfo()
      Clear the credentials to connect to the WebSocket endpoint.
      Returns:
      this object.
      Since:
      1.14

    • isExtended

      public boolean isExtended()
      Check if extended use of WebSocket frames are allowed.

      When extended use is allowed, values of RSV1/RSV2/RSV3 bits and opcode of frames are not checked. On the other hand, if not allowed (default), non-zero values for RSV1/RSV2/RSV3 bits and unknown opcodes cause an error. In such a case, onFrameError method of listeners are called and the WebSocket is eventually closed.

      Returns:
      true if extended use of WebSocket frames are allowed.

    • setExtended

      public WebSocket setExtended(boolean extended)
      Allow or disallow extended use of WebSocket frames.
      Parameters:
      extended - true to allow extended use of WebSocket frames.
      Returns:
      this object.

    • isAutoFlush

      public boolean isAutoFlush()
      Check if flush is performed automatically after sendFrame(WebSocketFrame) is done. The default value is true.
      Returns:
      true if flush is performed automatically.
      Since:
      1.5

    • setAutoFlush

      public WebSocket setAutoFlush(boolean auto)
      Enable or disable auto-flush of sent frames.
      Parameters:
      auto - true to enable auto-flush. false to disable it.
      Returns:
      this object.
      Since:
      1.5

    • isMissingCloseFrameAllowed

      public boolean isMissingCloseFrameAllowed()
      Check if this instance allows the server to close the WebSocket connection without sending a close frame to this client. The default value is true.
      Returns:
      true if the configuration allows for the server to close the WebSocket connection without sending a close frame to this client. false if the configuration requires that an error be reported via onError() method and onFrameError() method of WebSocketListener.
      Since:
      1.29

    • setMissingCloseFrameAllowed

      public WebSocket setMissingCloseFrameAllowed(boolean allowed)
      Set whether to allow the server to close the WebSocket connection without sending a close frame to this client.
      Parameters:
      allowed - true to allow the server to close the WebSocket connection without sending a close frame to this client. false to make this instance report an error when the end of the input stream of the WebSocket connection is reached before a close frame is read.
      Returns:
      this object.
      Since:
      1.29

    • isDirectTextMessage

      public boolean isDirectTextMessage()
      Check if text messages are passed to listeners without string conversion.

      If this method returns true, when a text message is received, onTextMessage(WebSocket, byte[]) will be called instead of onTextMessage(WebSocket, String). The purpose of this behavior is to skip internal string conversion which is performed in the implementation of ReadingThread.

      Returns:
      true if text messages are passed to listeners without string conversion.
      Since:
      2.6

    • setDirectTextMessage

      public WebSocket setDirectTextMessage(boolean direct)
      Set whether to receive text messages directly as byte arrays without string conversion.

      If true is set to this property, when a text message is received, onTextMessage(WebSocket, byte[]) will be called instead of onTextMessage(WebSocket, String). The purpose of this behavior is to skip internal string conversion which is performed in the implementation of ReadingThread.

      Parameters:
      direct - true to receive text messages as byte arrays.
      Returns:
      this object.
      Since:
      2.6

    • flush

      public WebSocket flush()
      Flush frames to the server. Flush is performed asynchronously.
      Returns:
      this object.
      Since:
      1.5

    • getFrameQueueSize

      public int getFrameQueueSize()
      Get the size of the frame queue. The default value is 0 and it means there is no limit on the queue size.
      Returns:
      The size of the frame queue.
      Since:
      1.15

    • setFrameQueueSize

      public WebSocket setFrameQueueSize(int size) throws IllegalArgumentException
      Set the size of the frame queue. The default value is 0 and it means there is no limit on the queue size.

      sendXxx methods queue a WebSocketFrame instance to the internal queue. If the number of frames in the queue has reached the upper limit (which has been set by this method) when a sendXxx method is called, the method blocks until the queue gets spaces.

      Under some conditions, even if the queue is full, sendXxx methods do not block. For example, in the case where the thread to send frames (WritingThread) is going to stop or has already stopped. In addition, method calls to send a control frame (e.g. sendClose() and sendPing()) do not block.

      Parameters:
      size - The queue size. 0 means no limit. Negative numbers are not allowed.
      Returns:
      this object.
      Throws:
      IllegalArgumentException - size is negative.
      Since:
      1.15

    • getMaxPayloadSize

      public int getMaxPayloadSize()
      Get the maximum payload size. The default value is 0 which means that the maximum payload size is not set and as a result frames are not split.
      Returns:
      The maximum payload size. 0 means that the maximum payload size is not set.
      Since:
      1.27

    • setMaxPayloadSize

      public WebSocket setMaxPayloadSize(int size) throws IllegalArgumentException
      Set the maximum payload size.

      Text, binary and continuation frames whose payload size is bigger than the maximum payload size will be split into multiple frames. Note that control frames (close, ping and pong frames) are not split as per the specification even if their payload size exceeds the maximum payload size.

      Parameters:
      size - The maximum payload size. 0 to unset the maximum payload size.
      Returns:
      this object.
      Throws:
      IllegalArgumentException - size is negative.
      Since:
      1.27

    • getPingInterval

      public long getPingInterval()
      Get the interval of periodical ping frames.
      Returns:
      The interval in milliseconds.
      Since:
      1.2

    • setPingInterval

      public WebSocket setPingInterval(long interval)
      Set the interval of periodical ping frames.

      Setting a positive number starts sending ping frames periodically. Setting zero stops the periodical sending. This method can be called both before and after connect() method.

      Parameters:
      interval - The interval in milliseconds. A negative value is regarded as zero.
      Returns:
      this object.
      Since:
      1.2

    • getPongInterval

      public long getPongInterval()
      Get the interval of periodical pong frames.
      Returns:
      The interval in milliseconds.
      Since:
      1.2

    • setPongInterval

      public WebSocket setPongInterval(long interval)
      Set the interval of periodical pong frames.

      Setting a positive number starts sending pong frames periodically. Setting zero stops the periodical sending. This method can be called both before and after connect() method.

      An excerpt from RFC 6455, 5.5.3. Pong

      A Pong frame MAY be sent unsolicited. This serves as a unidirectional heartbeat. A response to an unsolicited Pong frame is not expected.

      Parameters:
      interval - The interval in milliseconds. A negative value is regarded as zero.
      Returns:
      this object.
      Since:
      1.2

    • getPingPayloadGenerator

      public PayloadGenerator getPingPayloadGenerator()
      Get the generator of payload of ping frames that are sent automatically.
      Returns:
      The generator of payload ping frames that are sent automatically.
      Since:
      1.20

    • setPingPayloadGenerator

      public WebSocket setPingPayloadGenerator(PayloadGenerator generator)
      Set the generator of payload of ping frames that are sent automatically.
      Parameters:
      generator - The generator of payload ping frames that are sent automatically.
      Since:
      1.20

    • getPongPayloadGenerator

      public PayloadGenerator getPongPayloadGenerator()
      Get the generator of payload of pong frames that are sent automatically.
      Returns:
      The generator of payload pong frames that are sent automatically.
      Since:
      1.20

    • setPongPayloadGenerator

      public WebSocket setPongPayloadGenerator(PayloadGenerator generator)
      Set the generator of payload of pong frames that are sent automatically.
      Parameters:
      generator - The generator of payload ppng frames that are sent automatically.
      Since:
      1.20

    • getPingSenderName

      public String getPingSenderName()
      Get the name of the Timer that sends ping frames periodically.
      Returns:
      The Timer's name.
      Since:
      2.5

    • setPingSenderName

      public WebSocket setPingSenderName(String name)
      Set the name of the Timer that sends ping frames periodically.
      Parameters:
      name - A name for the Timer.
      Returns:
      this object.
      Since:
      2.5

    • getPongSenderName

      public String getPongSenderName()
      Get the name of the Timer that sends pong frames periodically.
      Returns:
      The Timer's name.
      Since:
      2.5

    • setPongSenderName

      public WebSocket setPongSenderName(String name)
      Set the name of the Timer that sends pong frames periodically.
      Parameters:
      name - A name for the Timer.
      Returns:
      this object.
      Since:
      2.5

    • addListener

      public WebSocket addListener(WebSocketListener listener)
      Add a listener to receive events on this WebSocket.
      Parameters:
      listener - A listener to add.
      Returns:
      this object.

    • addListeners

      public WebSocket addListeners(List<WebSocketListener> listeners)
      Add listeners.
      Parameters:
      listeners - Listeners to add. null is silently ignored. null elements in the list are ignored, too.
      Returns:
      this object.
      Since:
      1.14

    • removeListener

      public WebSocket removeListener(WebSocketListener listener)
      Remove a listener from this WebSocket.
      Parameters:
      listener - A listener to remove. null won't cause an error.
      Returns:
      this object.
      Since:
      1.13

    • removeListeners

      public WebSocket removeListeners(List<WebSocketListener> listeners)
      Remove listeners.
      Parameters:
      listeners - Listeners to remove. null is silently ignored. null elements in the list are ignored, too.
      Returns:
      this object.
      Since:
      1.14

    • clearListeners

      public WebSocket clearListeners()
      Remove all the listeners from this WebSocket.
      Returns:
      this object.
      Since:
      1.13

    • getSocket

      public Socket getSocket()
      Get the raw socket which this WebSocket uses internally if it has been established, yet.

      Version 2.9 has changed the behavior of this method, and this method may return null if the underlying socket has not been established yet. Consider using getConnectedSocket() method as necessary.

      Returns:
      The underlying Socket instance. This may be null in case the underlying socket has not been established, yet.
      See Also:

    • getConnectedSocket

      public Socket getConnectedSocket() throws WebSocketException
      Get the raw socket which this WebSocket uses internally. This will establish a connection to the server if not already done.
      Returns:
      The underlying Socket instance.
      Throws:
      WebSocketException
      Since:
      2.9

    • getURI

      public URI getURI()
      Get the URI of the WebSocket endpoint. The scheme part is either "ws" or "wss". The authority part is always empty.
      Returns:
      The URI of the WebSocket endpoint.
      Since:
      1.1

    • connect

      public WebSocket connect() throws WebSocketException
      Connect to the server, send an opening handshake to the server, receive the response and then start threads to communicate with the server.

      As necessary, addProtocol(String), addExtension(WebSocketExtension) addHeader(String, String) should be called before you call this method. It is because the parameters set by these methods are used in the opening handshake.

      Also, as necessary, getSocket() should be used to set up socket parameters before you call this method. For example, you can set the socket timeout like the following. Note that, however, because the version 2.9 changed the behavior of getSocket() and the method may return null if the underlying socket has not been established yet, you may need to use getConnectedSocket() method instead. 

       WebSocket websocket = ......;
 websocket.getSocket().setSoTimeout(5000);

 // getConnectedSocket() instead of getSocket(), since version 2.9.
 websocket.getConnectedSocket().setSoTimeout(5000);

      If the WebSocket endpoint requires Basic Authentication, you can set credentials by setUserInfo(userInfo) or setUserInfo(id, password) before you call this method. Note that if the URI passed to WebSocketFactory .createSocket method contains the user-info part, you don't have to call setUserInfo method.

      Note that this method can be called at most only once regardless of whether this method succeeded or failed. If you want to re-connect to the WebSocket endpoint, you have to create a new WebSocket instance again by calling one of createSocket methods of a WebSocketFactory. You may find recreate() method useful if you want to create a new WebSocket instance that has the same settings as this instance. (But settings you made on the raw socket are not copied.)

      Returns:
      this object.
      Throws:
      WebSocketException -
      • The current state of the WebSocket is not CREATED
      • Connecting the server failed.
      • The opening handshake failed.

    • connect

      public Future<WebSocket> connect(ExecutorService executorService)
      Execute connect() asynchronously using the given ExecutorService. This method is just an alias of the following.
      executorService.submit(connectable())
      Parameters:
      executorService - An ExecutorService to execute a task created by connectable().
      Returns:
      The value returned from ExecutorService.submit(Callable).
      Throws:
      NullPointerException - If the given ExecutorService is null.
      RejectedExecutionException - If the given ExecutorService rejected the task created by connectable().
      Since:
      1.7
      See Also:

    • connectable

      public Callable<WebSocket> connectable()
      Get a new Callable<WebSocket> instance whose call() method calls connect() method of this WebSocket instance.
      Returns:
      A new Callable<WebSocket> instance for asynchronous connect().
      Since:
      1.7
      See Also:

    • connectAsynchronously

      public WebSocket connectAsynchronously()
      Execute connect() asynchronously by creating a new thread and calling connect() in the thread. If connect() failed, onConnectError() method of WebSocketListener is called.
      Returns:
      this object.
      Since:
      1.8

    • disconnect

      public WebSocket disconnect()
      Disconnect the WebSocket.

      This method is an alias of disconnect(WebSocketCloseCode.NORMAL, null).

      Returns:
      this object.

    • disconnect

      public WebSocket disconnect(int closeCode)
      Disconnect the WebSocket.

      This method is an alias of disconnect(closeCode, null).

      Parameters:
      closeCode - The close code embedded in a close frame which this WebSocket client will send to the server.
      Returns:
      this object.
      Since:
      1.5

    • disconnect

      public WebSocket disconnect(String reason)
      Disconnect the WebSocket.

      This method is an alias of disconnect(WebSocketCloseCode.NORMAL, reason).

      Parameters:
      reason - The reason embedded in a close frame which this WebSocket client will send to the server. Note that the length of the bytes which represents the given reason must not exceed 125. In other words, (reason.getBytes("UTF-8").length <= 125) must be true.
      Returns:
      this object.
      Since:
      1.5

    • disconnect

      public WebSocket disconnect(int closeCode, String reason)
      Disconnect the WebSocket.

      This method is an alias of disconnect(closeCode, reason, 10000L).

      Parameters:
      closeCode - The close code embedded in a close frame which this WebSocket client will send to the server.
      reason - The reason embedded in a close frame which this WebSocket client will send to the server. Note that the length of the bytes which represents the given reason must not exceed 125. In other words, (reason.getBytes("UTF-8").length <= 125) must be true.
      Returns:
      this object.
      Since:
      1.5
      See Also:

    • disconnect

      public WebSocket disconnect(int closeCode, String reason, long closeDelay)
      Disconnect the WebSocket.
      Parameters:
      closeCode - The close code embedded in a close frame which this WebSocket client will send to the server.
      reason - The reason embedded in a close frame which this WebSocket client will send to the server. Note that the length of the bytes which represents the given reason must not exceed 125. In other words, (reason.getBytes("UTF-8").length <= 125) must be true.
      closeDelay - Delay in milliseconds before calling Socket.close() forcibly. This safeguard is needed for the case where the server fails to send back a close frame. The default value is 10000 (= 10 seconds). When a negative value is given, the default value is used. If a very short time (e.g. 0) is given, it is likely to happen either (1) that this client will fail to send a close frame to the server (in this case, you will probably see an error message "Flushing frames to the server failed: Socket closed") or (2) that the WebSocket connection will be closed before this client receives a close frame from the server (in this case, the second argument of WebSocketListener.onDisconnected will be null).
      Returns:
      this object.
      Since:
      1.26
      See Also:

    • getAgreedExtensions

      public List<WebSocketExtension> getAgreedExtensions()
      Get the agreed extensions.

      This method works correctly only after connect() succeeds (= after the opening handshake succeeds).

      Returns:
      The agreed extensions.

    • getAgreedProtocol

      public String getAgreedProtocol()
      Get the agreed protocol.

      This method works correctly only after connect() succeeds (= after the opening handshake succeeds).

      Returns:
      The agreed protocol.

    • sendFrame

      public WebSocket sendFrame(WebSocketFrame frame)
      Send a WebSocket frame to the server.

      This method just queues the given frame. Actual transmission is performed asynchronously.

      When the current state of this WebSocket is not OPEN, this method does not accept the frame.

      Sending a close frame changes the state to CLOSING (if the current state is neither CLOSING nor CLOSED).

      Note that the validity of the give frame is not checked. For example, even if the payload length of a given frame is greater than 125 and the opcode indicates that the frame is a control frame, this method accepts the given frame.

      Parameters:
      frame - A WebSocket frame to be sent to the server. If null is given, nothing is done.
      Returns:
      this object.

    • splitIfNecessary

      private List<WebSocketFrame> splitIfNecessary(WebSocketFrame frame)

    • sendContinuation

      public WebSocket sendContinuation()
      Send a continuation frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createContinuationFrame()).

      Note that the FIN bit of a frame sent by this method is false. If you want to set the FIN bit, use sendContinuation(boolean fin) with fin=true.

      Returns:
      this object.

    • sendContinuation

      public WebSocket sendContinuation(boolean fin)
      Send a continuation frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createContinuationFrame().setFin(fin)).

      Parameters:
      fin - The FIN bit value.
      Returns:
      this object.

    • sendContinuation

      public WebSocket sendContinuation(String payload)
      Send a continuation frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createContinuationFrame(payload)).

      Note that the FIN bit of a frame sent by this method is false. If you want to set the FIN bit, use sendContinuation(String payload, boolean fin) with fin=true.

      Parameters:
      payload - The payload of a continuation frame.
      Returns:
      this object.

    • sendContinuation

      public WebSocket sendContinuation(String payload, boolean fin)
      Send a continuation frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createContinuationFrame(payload).setFin(fin)).

      Parameters:
      payload - The payload of a continuation frame.
      fin - The FIN bit value.
      Returns:
      this object.

    • sendContinuation

      public WebSocket sendContinuation(byte[] payload)
      Send a continuation frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createContinuationFrame(payload)).

      Note that the FIN bit of a frame sent by this method is false. If you want to set the FIN bit, use sendContinuation(byte[] payload, boolean fin) with fin=true.

      Parameters:
      payload - The payload of a continuation frame.
      Returns:
      this object.

    • sendContinuation

      public WebSocket sendContinuation(byte[] payload, boolean fin)
      Send a continuation frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createContinuationFrame(payload).setFin(fin)).

      Parameters:
      payload - The payload of a continuation frame.
      fin - The FIN bit value.
      Returns:
      this object.

    • sendText

      public WebSocket sendText(String message)
      Send a text message to the server.

      This method is an alias of sendFrame(WebSocketFrame.createTextFrame(message)).

      If you want to send a text frame that is to be followed by continuation frames, use setText(String payload, boolean fin) with fin=false.

      Parameters:
      message - A text message to be sent to the server.
      Returns:
      this object.

    • sendText

      public WebSocket sendText(String payload, boolean fin)
      Send a text frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createTextFrame(payload).setFin(fin)).

      Parameters:
      payload - The payload of a text frame.
      fin - The FIN bit value.
      Returns:
      this object.

    • sendBinary

      public WebSocket sendBinary(byte[] message)
      Send a binary message to the server.

      This method is an alias of sendFrame(WebSocketFrame.createBinaryFrame(message)).

      If you want to send a binary frame that is to be followed by continuation frames, use setBinary(byte[] payload, boolean fin) with fin=false.

      Parameters:
      message - A binary message to be sent to the server.
      Returns:
      this object.

    • sendBinary

      public WebSocket sendBinary(byte[] payload, boolean fin)
      Send a binary frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createBinaryFrame(payload).setFin(fin)).

      Parameters:
      payload - The payload of a binary frame.
      fin - The FIN bit value.
      Returns:
      this object.

    • sendClose

      public WebSocket sendClose()
      Send a close frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createCloseFrame()).

      Returns:
      this object.

    • sendClose

      public WebSocket sendClose(int closeCode)
      Send a close frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createCloseFrame(closeCode)).

      Parameters:
      closeCode - The close code.
      Returns:
      this object.
      See Also:

    • sendClose

      public WebSocket sendClose(int closeCode, String reason)
      Send a close frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createCloseFrame(closeCode, reason)).

      Parameters:
      closeCode - The close code.
      reason - The close reason. Note that a control frame's payload length must be 125 bytes or less (RFC 6455, 5.5. Control Frames).
      Returns:
      this object.
      See Also:

    • sendPing

      public WebSocket sendPing()
      Send a ping frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createPingFrame()).

      Returns:
      this object.

    • sendPing

      public WebSocket sendPing(byte[] payload)
      Send a ping frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createPingFrame(payload)).

      Parameters:
      payload - The payload for a ping frame. Note that a control frame's payload length must be 125 bytes or less (RFC 6455, 5.5. Control Frames).
      Returns:
      this object.

    • sendPing

      public WebSocket sendPing(String payload)
      Send a ping frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createPingFrame(payload)).

      Parameters:
      payload - The payload for a ping frame. Note that a control frame's payload length must be 125 bytes or less (RFC 6455, 5.5. Control Frames).
      Returns:
      this object.

    • sendPong

      public WebSocket sendPong()
      Send a pong frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createPongFrame()).

      Returns:
      this object.

    • sendPong

      public WebSocket sendPong(byte[] payload)
      Send a pong frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createPongFrame(payload)).

      Parameters:
      payload - The payload for a pong frame. Note that a control frame's payload length must be 125 bytes or less (RFC 6455, 5.5. Control Frames).
      Returns:
      this object.

    • sendPong

      public WebSocket sendPong(String payload)
      Send a pong frame to the server.

      This method is an alias of sendFrame(WebSocketFrame.createPongFrame(payload)).

      Parameters:
      payload - The payload for a pong frame. Note that a control frame's payload length must be 125 bytes or less (RFC 6455, 5.5. Control Frames).
      Returns:
      this object.

    • changeStateOnConnect

      private void changeStateOnConnect() throws WebSocketException
      Throws:
      WebSocketException

    • shakeHands

      private Map<String,List<String>> shakeHands(Socket socket) throws WebSocketException
      Perform the opening handshake.
      Throws:
      WebSocketException

    • openInputStream

      private WebSocketInputStream openInputStream(Socket socket) throws WebSocketException
      Open the input stream of the WebSocket connection. The stream is used by the reading thread.
      Throws:
      WebSocketException

    • openOutputStream

      private WebSocketOutputStream openOutputStream(Socket socket) throws WebSocketException
      Open the output stream of the WebSocket connection. The stream is used by the writing thread.
      Throws:
      WebSocketException

    • generateWebSocketKey

      private static String generateWebSocketKey()
      Generate a value for Sec-WebSocket-Key.

      The request MUST include a header field with the name Sec-WebSocket-Key. The value of this header field MUST be a nonce consisting of a randomly selected 16-byte value that has been base64-encoded (see Section 4 of RFC 4648). The nonce MUST be selected randomly for each connection.

      Returns:
      A randomly generated WebSocket key.

    • writeHandshake

      private void writeHandshake(WebSocketOutputStream output, String key) throws WebSocketException
      Send an opening handshake request to the WebSocket server.
      Throws:
      WebSocketException

    • readHandshake

      private Map<String,List<String>> readHandshake(WebSocketInputStream input, String key) throws WebSocketException
      Receive an opening handshake response from the WebSocket server.
      Throws:
      WebSocketException

    • startThreads

      private void startThreads()
      Start both the reading thread and the writing thread.

      The reading thread will call onReadingThreadStarted() as its first step. Likewise, the writing thread will call onWritingThreadStarted() as its first step. After both the threads have started, onThreadsStarted() is called.

    • stopThreads

      private void stopThreads(long closeDelay)
      Stop both the reading thread and the writing thread.

      The reading thread will call onReadingThreadFinished(WebSocketFrame) as its last step. Likewise, the writing thread will call onWritingThreadFinished(WebSocketFrame) as its last step. After both the threads have stopped, onThreadsFinished() is called.

    • getInput

      WebSocketInputStream getInput()
      Get the input stream of the WebSocket connection.

    • getOutput

      WebSocketOutputStream getOutput()
      Get the output stream of the WebSocket connection.

    • getStateManager

      StateManager getStateManager()
      Get the manager that manages the state of this WebSocket instance.

    • getListenerManager

      ListenerManager getListenerManager()
      Get the manager that manages registered listeners.

    • getHandshakeBuilder

      HandshakeBuilder getHandshakeBuilder()
      Get the handshake builder. HandshakeReader uses this method.

    • setAgreedExtensions

      void setAgreedExtensions(List<WebSocketExtension> extensions)
      Set the agreed extensions. HandshakeReader uses this method.

    • setAgreedProtocol

      void setAgreedProtocol(String protocol)
      Set the agreed protocol. HandshakeReader uses this method.

    • onReadingThreadStarted

      void onReadingThreadStarted()
      Called by the reading thread as its first step.

    • onWritingThreadStarted

      void onWritingThreadStarted()
      Called by the writing thread as its first step.

    • callOnConnectedIfNotYet

      private void callOnConnectedIfNotYet()
      Call WebSocketListener.onConnected(WebSocket, Map) method of the registered listeners if it has not been called yet. Either the reading thread or the writing thread calls this method.

    • onThreadsStarted

      private void onThreadsStarted()
      Called when both the reading thread and the writing thread have started. This method is called in the context of either the reading thread or the writing thread.

    • onReadingThreadFinished

      void onReadingThreadFinished(WebSocketFrame closeFrame)
      Called by the reading thread as its last step.

    • onWritingThreadFinished

      void onWritingThreadFinished(WebSocketFrame closeFrame)
      Called by the writing thread as its last step.

    • onThreadsFinished

      private void onThreadsFinished()
      Called when both the reading thread and the writing thread have finished. This method is called in the context of either the reading thread or the writing thread.

    • finish

      void finish()

    • finishAsynchronously

      private void finishAsynchronously()
      Call finish() from within a separate thread.

    • findAgreedPerMessageCompressionExtension

      private PerMessageCompressionExtension findAgreedPerMessageCompressionExtension()
      Find a per-message compression extension from among the agreed extensions.

    • getPerMessageCompressionExtension

      PerMessageCompressionExtension getPerMessageCompressionExtension()
      Get the PerMessageCompressionExtension in the agreed extensions. This method returns null if a per-message compression extension is not found in the agreed extensions.