WebSocket (NetPhantom® 8.0 Java API Specification)

java.lang.Object
- com.netphantom.common.websocket.WebSocket

Direct Known Subclasses:

WebSocketClient, WebSocketServer
```
public abstract class WebSocket
extends Object
```
Base WebSocket implementation supporting RFC 6455 (The WebSocket Protocol, December 2011) with backward compatibility for the old Hixie-76 framing.
Original implementation based on "HyBi Working Group, draft-ietf-hybi-thewebsocketprotocol-07, April 22, 2011, by I. Fette, Google Inc." — updated to RFC 6455 in March 2026.

See https://tools.ietf.org/html/rfc6455 for more information.

The WebSocket protocol enables two-way communication between a user agent running untrusted code running in a controlled environment to a remote host that has opted-in to communications from that code. The security model used for this is the Origin-based security model commonly used by Web browsers. The protocol consists of an initial handshake followed by basic message framing, layered over TCP. The goal of this technology is to provide a mechanism for browser-based applications that need two-way communication with servers that does not rely on opening multiple HTTP connections (e.g. using XMLHttpRequest or <iframe>s and long polling).

Author:

Christopher Mindus

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class WebSocket.State
The states enumeration for client web sockets.

Nested Classes
Modifier and Type	Class and Description
`static class`	`WebSocket.State` The states enumeration for client web sockets.

Field Summary

Fields
Modifier and Type	Field and Description
`protected static String`	`ACCEPT_GUID` The GUID for the WebSocket handshake accept computation (RFC 6455 Section 4.2.2).
`static int`	`CLOSE_GOING_AWAY` RFC 6455 close status code: Going Away (1001).
`static int`	`CLOSE_NORMAL` RFC 6455 close status code: Normal Closure (1000).
`static int`	`CLOSE_PROTOCOL_ERROR` RFC 6455 close status code: Protocol Error (1002).
`protected static String`	`CRLF` CR/LF string.
`protected BufferedInputStream`	`input` The input stream.
`protected boolean`	`isSecure` If this is secured with SSL or not (WS or WSS).
`protected BufferedOutputStream`	`output` The output stream.
`protected int`	`protocolVersion` Protocol version (13 for RFC 6455, 0 for old Hixie-76).
`protected String`	`ssubProtocol` The server-accepted sub-protocol, null for none.
`protected WebSocket.State`	`state` State of connection.

Constructor Summary

Constructors
Constructor and Description
`WebSocket(InputStream input, OutputStream output, boolean isSecure)` Establishes the WebSocket connection using streams only (no raw Socket reference).
`WebSocket(Socket socket, boolean isSecure)` Establishes the WebSocket connection using an already connected socket.
`WebSocket(Socket socket, InputStream input, OutputStream output, boolean isSecure)` Establishes the WebSocket connection using an already connected socket.

Method Summary

All Methods Static Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`boolean`	`close()` Closes the connection gracefully.
`void`	`closeSocket()` Closes the socket connection without informing the other WebSocket party.
`void`	`closeSocketHard()` Closes the socket connection in a very hard way.
`byte[]`	`getBinaryMessage()` Gets a binary message.
`boolean`	`getOldTextProtocol()` Gets the flag for "old" protocol for UTF-8 text, i.e.
`int`	`getProtocolVersion()` Gets the protocol version.
`String`	`getServerSubProtocol()` Gets the server-accepted sub-protocol, null for none.
`WebSocket.State`	`getState()` Gets the current state of the connection.
`String`	`getTextMessage()` Gets a text message.
`boolean`	`hasBinaryMessage()` Checks if the message received is a binary message.
`boolean`	`hasTextMessage()` Checks if the message received is a text message.
`protected abstract boolean`	`isServerSide()` Returns true if this is the server side of the WebSocket connection.
`static boolean`	`isVerbose()` Checks if verbose output is enabled.
`protected static void`	`log(String msg)` Logs a message if verbose mode is enabled.
`protected static void`	`log(String msg, Throwable t)` Logs a message with an exception if verbose mode is enabled.
`int`	`readMessage()` Reads a message.
`void`	`sendBinaryData(byte[] data)` Sends binary data.
`void`	`sendBinaryData(byte[] data, int offset, int length)` Sends binary data.
`void`	`sendCloseFrame(int statusCode, String reason)` Sends a close frame with a status code and optional reason (RFC 6455 Section 5.5.1).
`void`	`sendText(String message)` Sends a text message.
`boolean`	`setOldTextProtocol(boolean on)` Sets the "old" protocol for UTF-8 text, i.e.
`void`	`setProtocolVersion(int version)` Sets the protocol version.
`static void`	`setVerbose(boolean on)` Sets the verbose flag.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - CRLF
```
protected static final String CRLF
```
    CR/LF string.
    
    See Also:
    
    Constant Field Values
  - ACCEPT_GUID
```
protected static final String ACCEPT_GUID
```
    The GUID for the WebSocket handshake accept computation (RFC 6455 Section 4.2.2).
    
    See Also:
    
    Constant Field Values
  - CLOSE_NORMAL
```
public static final int CLOSE_NORMAL
```
    RFC 6455 close status code: Normal Closure (1000).
    
    See Also:
    
    Constant Field Values
  - CLOSE_GOING_AWAY
```
public static final int CLOSE_GOING_AWAY
```
    RFC 6455 close status code: Going Away (1001).
    
    See Also:
    
    Constant Field Values
  - CLOSE_PROTOCOL_ERROR
```
public static final int CLOSE_PROTOCOL_ERROR
```
    RFC 6455 close status code: Protocol Error (1002).
    
    See Also:
    
    Constant Field Values
  - isSecure
```
protected final boolean isSecure
```
    If this is secured with SSL or not (WS or WSS).
  - input
```
protected final BufferedInputStream input
```
    The input stream.
  - output
```
protected final BufferedOutputStream output
```
    The output stream.
  - ssubProtocol
```
protected String ssubProtocol
```
    The server-accepted sub-protocol, null for none.
  - state
```
protected volatile WebSocket.State state
```
    State of connection. Volatile for cross-thread visibility.
  - protocolVersion
```
protected int protocolVersion
```
    Protocol version (13 for RFC 6455, 0 for old Hixie-76).
- Constructor Detail
  - WebSocket
```
public WebSocket(Socket socket,
                 boolean isSecure)
          throws IOException
```
    Establishes the WebSocket connection using an already connected socket. This socket can be SSL or plain. The socket can also have undergone some kind of proxy such as Socks or HTTP before ending up here.
    
    Parameters:
    
    socket - The established socket.
    
    isSecure - If the connection is secure.
    
    Throws:
    
    IOException - For failures.
  - WebSocket
```
public WebSocket(Socket socket,
                 InputStream input,
                 OutputStream output,
                 boolean isSecure)
          throws IOException
```
    Establishes the WebSocket connection using an already connected socket. This socket can be SSL or plain. The socket can also have undergone some kind of proxy such as Socks or HTTP before ending up here.
    
    Parameters:
    
    socket - The established socket.
    
    input - The input stream.
    
    output - The output stream.
    
    isSecure - If the connection is secure.
    
    Throws:
    
    IOException - For failures.
  - WebSocket
```
public WebSocket(InputStream input,
                 OutputStream output,
                 boolean isSecure)
          throws IOException
```
    Establishes the WebSocket connection using streams only (no raw Socket reference). This constructor is used when the underlying socket is wrapped in an ISocket adapter and the raw java.net.Socket is not directly accessible.
    Note: close operations will only close the streams, not the underlying socket. The caller (e.g. HttpRequestParser) is responsible for socket lifecycle.
    
    Parameters:
    
    input - The input stream.
    
    output - The output stream.
    
    isSecure - If the connection is secure.
    
    Throws:
    
    IOException - For failures.
- Method Detail
  - setVerbose
```
public static void setVerbose(boolean on)
```
    Sets the verbose flag.
    
    Parameters:
    
    on - The state of the verbose output.
  - isVerbose
```
public static boolean isVerbose()
```
    Checks if verbose output is enabled.
  - log
```
protected static void log(String msg)
```
    Logs a message if verbose mode is enabled.
    
    Parameters:
    
    msg - The message to log.
  - log
```
protected static void log(String msg,
                          Throwable t)
```
    Logs a message with an exception if verbose mode is enabled.
    
    Parameters:
    
    msg - The message to log.
    
    t - The exception to log.
  - isServerSide
```
protected abstract boolean isServerSide()
```
    Returns true if this is the server side of the WebSocket connection. Used to determine masking behavior: client-to-server frames are masked, server-to-client frames are not.
  - setOldTextProtocol
```
public final boolean setOldTextProtocol(boolean on)
```
    Sets the "old" protocol for UTF-8 text, i.e. frame is delimited by bytes 0x00 and 0xFF.
    
    Parameters:
    
    on - Flag to turn on or off the mode.
    
    Returns:
    
    The previous mode.
  - getOldTextProtocol
```
public final boolean getOldTextProtocol()
```
    Gets the flag for "old" protocol for UTF-8 text, i.e. frame is delimited by bytes 0x00 and 0xFF.
    
    Returns:
    
    The "old" protocol flag for UTF-8 text.
  - getProtocolVersion
```
public final int getProtocolVersion()
```
    Gets the protocol version. This call must be done after the performHandshake method. Returns 13 for RFC 6455, or 0 for old Hixie-76.
  - setProtocolVersion
```
public final void setProtocolVersion(int version)
```
    Sets the protocol version. This call must be done prior to the performHandshake method.
    
    Parameters:
    
    version - The version (13 for RFC 6455).
  - getState
```
public final WebSocket.State getState()
```
    Gets the current state of the connection.
  - getServerSubProtocol
```
public final String getServerSubProtocol()
```
    Gets the server-accepted sub-protocol, null for none.
  - readMessage
```
public final int readMessage()
                      throws IOException
```
    Reads a message. The return code is -1 if state should be checked, e.g. if connection is closed or closing, 0 if there is a text message present, 1 if there is a binary message present.
    
    Returns:
    
    -1 = check state, 0 = text message present, 1 = binary message present.
    
    Throws:
    
    IOException - for frame and protocol errors.
  - hasTextMessage
```
public final boolean hasTextMessage()
```
    Checks if the message received is a text message. If no message is received, false is always returned.
  - hasBinaryMessage
```
public final boolean hasBinaryMessage()
```
    Checks if the message received is a binary message. If no message is received, false is always returned.
  - getTextMessage
```
public String getTextMessage()
```
    Gets a text message.
    
    Returns:
    
    null if no message is available.
  - getBinaryMessage
```
public byte[] getBinaryMessage()
```
    Gets a binary message.
    
    Returns:
    
    null if no message is available.
  - sendText
```
public final void sendText(String message)
                    throws IOException
```
    Sends a text message.
    
    Parameters:
    
    message - A text message.
    
    Throws:
    
    IOException - for frame and protocol errors.
    
    IllegalArgumentException - for illegal arguments.
  - sendBinaryData
```
public final void sendBinaryData(byte[] data)
                          throws IOException
```
    Sends binary data.
    
    Parameters:
    
    data - the binary data to send.
    
    Throws:
    
    IOException - for frame and protocol errors.
    
    IllegalArgumentException - for illegal arguments.
  - sendBinaryData
```
public final void sendBinaryData(byte[] data,
                                 int offset,
                                 int length)
                          throws IOException
```
    Sends binary data.
    
    Parameters:
    
    data - the binary data to send.
    
    offset - the starting offset in the data.
    
    length - the length of data to send.
    
    Throws:
    
    IOException - for frame and protocol errors.
    
    IllegalArgumentException - for illegal arguments.
  - sendCloseFrame
```
public final void sendCloseFrame(int statusCode,
                                 String reason)
                          throws IOException
```
    Sends a close frame with a status code and optional reason (RFC 6455 Section 5.5.1).
    
    Parameters:
    
    statusCode - The close status code (e.g. CLOSE_NORMAL).
    
    reason - Optional human-readable reason, may be null.
    
    Throws:
    
    IOException - For I/O errors.
  - close
```
public final boolean close()
                    throws IOException
```
    Closes the connection gracefully.
    
    Returns:
    
    false if the connection cannot be closed: check the state, it must be connected and not CLOSING. Returns true for success and also if the connection is already closed.
    
    Throws:
    
    IOException - for frame and protocol errors.
  - closeSocket
```
public final void closeSocket()
```
    Closes the socket connection without informing the other WebSocket party. This method should be avoided.
  - closeSocketHard
```
public final void closeSocketHard()
```
    Closes the socket connection in a very hard way. This method should be avoided. All communication are inhibited directly and then the socket close directly.

Class WebSocket

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

CRLF

ACCEPT_GUID

CLOSE_NORMAL

CLOSE_GOING_AWAY

CLOSE_PROTOCOL_ERROR

isSecure

input

output

ssubProtocol

state

protocolVersion

Constructor Detail

WebSocket

WebSocket

WebSocket

Method Detail

setVerbose

isVerbose

log

log

isServerSide

setOldTextProtocol

getOldTextProtocol

getProtocolVersion

setProtocolVersion

getState

getServerSubProtocol

readMessage

hasTextMessage

hasBinaryMessage

getTextMessage

getBinaryMessage

sendText

sendBinaryData

sendBinaryData

sendCloseFrame

close

closeSocket

closeSocketHard