CkWebSocket Java Reference Documentation

CkWebSocket

Current Version: 9.5.0.97

Provides an API for implementing the client side of the WebSocket protocol.

Object Creation

CkWebSocket obj = new CkWebSocket();

Properties

CloseAutoRespond
boolean get_CloseAutoRespond();
void put_CloseAutoRespond(boolean newVal);
Introduced in version 9.5.0.70

If true, then a Close control frame is automatically sent in response to receiving a Close control frame (assuming that we did not initiate the Close in the first place). When the Close frame has both been received and sent, the underlying connection is automatically closed (as per the WebSocket protocol RFC specifications). Thus, if this property is true, then two things automatically happen when a Close frame is received: (1) a Close frame is sent in response, and (2) the connection is closed.

The default value of this property is true.

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CloseReason
void get_CloseReason(CkString str);
String closeReason();
Introduced in version 9.5.0.70

The reason string received with the Close frame, if any.

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CloseReceived
boolean get_CloseReceived();
Introduced in version 9.5.0.70

If true, then a Close frame was already received on this websocket connection. If CloseAutoRespond is false, then an application can check this property value to determine if a Close frame should be sent in response.

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CloseStatusCode
int get_CloseStatusCode();
Introduced in version 9.5.0.70

The status code received with the Close frame. If no status code was provided, or no Close frame has yet been received, then this property will be 0.

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DebugLogFilePath
void get_DebugLogFilePath(CkString str);
String debugLogFilePath();
void put_DebugLogFilePath(String newVal);

If set to a file path, causes each Chilkat method or property call to automatically append it's LastErrorText to the specified log file. The information is appended such that if a hang or crash occurs, it is possible to see the context in which the problem occurred, as well as a history of all Chilkat calls up to the point of the problem. The VerboseLogging property can be set to provide more detailed information.

This property is typically used for debugging the rare cases where a Chilkat method call hangs or generates an exception that halts program execution (i.e. crashes). A hang or crash should generally never happen. The typical causes of a hang are:

  1. a timeout related property was set to 0 to explicitly indicate that an infinite timeout is desired,
  2. the hang is actually a hang within an event callback (i.e. it is a hang within the application code), or
  3. there is an internal problem (bug) in the Chilkat code that causes the hang.

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FinalFrame
boolean get_FinalFrame();
Introduced in version 9.5.0.70

true if the last data frame received by calling ReadFrame was a final frame. Otherwise false.

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FrameDataLen
int get_FrameDataLen();
Introduced in version 9.5.0.70

The number of bytes accumulated from one or more calls to ReadFrame. Accumulated incoming frame data can be retrieved by calling GetFrameData, GetFrameDataSb, or GetFrameDataBd.

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FrameOpcode
void get_FrameOpcode(CkString str);
String frameOpcode();
Introduced in version 9.5.0.70

Indicates the type of frame received in the last call to ReadFrame. Possible values are "Continuation", "Text", "Binary", "Close", "Ping", or "Pong". Initially this property is set to the empty string because nothing has yet been received.

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FrameOpcodeInt
int get_FrameOpcodeInt();
Introduced in version 9.5.0.70

The integer value of the opcode (type of frame) received in the last call to ReadFrame. Possible values are:

0 - Continuation
1 - Text
2 - Binary
8 - Close
9 - Ping
10 - Pong

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HeartbeatMs
int get_HeartbeatMs();
void put_HeartbeatMs(int newVal);
Introduced in version 9.5.0.97

The time interval, in milliseconds, between AbortCheck event callbacks. The heartbeat provides a means for an application to monitor a method call that has event callbacks, and to abort it while in progress.

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IdleTimeoutMs
int get_IdleTimeoutMs();
void put_IdleTimeoutMs(int newVal);

The maximum amount of time to wait for additional incoming data when receiving, or the max time to wait to send additional data. The default value is 30000 (30 seconds). This is not an overall max timeout. Rather, it is the maximum time to wait when receiving or sending has halted.

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IsConnected
boolean get_IsConnected();
Introduced in version 9.5.0.70

Returns true if the websocket is connected. Otherwise returns false.

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LastErrorHtml
void get_LastErrorHtml(CkString str);
String lastErrorHtml();

Provides information in HTML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorText
void get_LastErrorText(CkString str);
String lastErrorText();

Provides information in plain-text format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastErrorXml
void get_LastErrorXml(CkString str);
String lastErrorXml();

Provides information in XML format about the last method/property called. If a method call returns a value indicating failure, or behaves unexpectedly, examine this property to get more information.

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LastMethodSuccess
boolean get_LastMethodSuccess();
void put_LastMethodSuccess(boolean newVal);

Indicate whether the last method call succeeded or failed. A value of true indicates success, a value of false indicates failure. This property is automatically set for method calls. It is not modified by property accesses. The property is automatically set to indicate success for the following types of method calls:

  • Any method that returns a string.
  • Any method returning a Chilkat object, binary bytes, or a date/time.
  • Any method returning a standard boolean status value where success = true and failure = false.
  • Any method returning an integer where failure is defined by a return value less than zero.

Note: Methods that do not fit the above requirements will always set this property equal to true. For example, a method that returns no value (such as a "void" in C++) will technically always succeed.

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NeedSendPong
boolean get_NeedSendPong();
Introduced in version 9.5.0.70

If true, then a Ping frame was received, but no Pong frame has yet been sent in response. The application should send a Pong frame by calling SendPong as soon as possible.

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PingAutoRespond
boolean get_PingAutoRespond();
void put_PingAutoRespond(boolean newVal);
Introduced in version 9.5.0.70

If true, then a Pong frame is automatically sent when a Ping frame is received. If set to false, then the application may check the NeedSendPong property to determine if a Pong response is needed, and if so, may call the SendPong method to send a Pong.

Note: If this property is true, then the ReadFrame method will auto-consume incoming Ping frames. In other words, ReadFrame will continue with reading the next incoming frame (thus Ping frames will never be returned to the application). This relieves the application from having to worry about receiving and handling spurious Ping frames.

The default value is true.

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PongAutoConsume
boolean get_PongAutoConsume();
void put_PongAutoConsume(boolean newVal);
Introduced in version 9.5.0.70

If true, then incoming Pong frames are automatically consumed, and a call to ReadFrame will continue reading until it receives a non-Pong frame. The PongConsumed property can be checked to see if the last ReadFrame method call auto-consumed a Pong frame.

The default value is true.

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PongConsumed
boolean get_PongConsumed();
Introduced in version 9.5.0.70

Is true if the last call to ReadFrame auto-consumed a Pong frame. This property is reset to false each time a ReadFrame method is called, and will get set to true if (1) the PongAutoConsume property is true and (2) a Pong frame was consumed within the ReadFrame method.

The purpose of PongAutoConsume and PongConsumed is to eliminate the concern for unanticipated Pong frames in the stream. In the websocket protocol, both sides (client and server) may send Pong frames at any time. In addition, if a Ping frame is sent, the corresponding Pong response frame can arrive at some unanticipated point later in the conversation. It's also possible, if several Ping frames are sent, that a Pong response frame is only sent for the most recent Ping frame. The default behavior of Chilkat's WebSocket API is to auto-consume incoming Pong frames and set this property to true. This allows the application to call a ReadFrame method for whatever application data frame it may be expecting, without needing to be concerned if the next incoming frame is a Pong frame.

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ReadFrameFailReason
int get_ReadFrameFailReason();
Introduced in version 9.5.0.70

If the ReadFrame method returns false, this property holds the fail reason. It can have one of the following values:

0 - No failure.
1 - Read Timeout.
2 - Aborted by Application Callback.
3 - Fatal Socket Error (Lost Connection).
4 - Received invalid WebSocket frame bytes.
99 - A catch-all for any unknown failure.  (Should not ever occur.  If it does, contact Chilkat.)

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UncommonOptions
void get_UncommonOptions(CkString str);
String uncommonOptions();
Introduced in version 9.5.0.80

This is a catch-all property to be used for uncommon needs. This property defaults to the empty string and should typically remain empty. Can be set to a list of the following comma separated keywords:

  • "ProtectFromVpn" - Introduced in v9.5.0.80. On Android systems, will bypass any VPN that may be installed or active.

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VerboseLogging
boolean get_VerboseLogging();
void put_VerboseLogging(boolean newVal);

If set to true, then the contents of LastErrorText (or LastErrorXml, or LastErrorHtml) may contain more verbose information. The default value is false. Verbose logging should only be used for debugging. The potentially large quantity of logged information may adversely affect peformance.

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Version
void get_Version(CkString str);
String version();

Version of the component/library, such as "9.5.0.94"

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Methods

AddClientHeaders
boolean AddClientHeaders();
Introduced in version 9.5.0.70

Adds the required WebSocket client-side open handshake headers. The headers specifically added to the previously specified REST object (in the call to UseConnection) are:

Upgrade: websocket
Connection: Upgrade
Sec-WebSocket-Key: ...
Sec-WebSocket-Version: 13

Returns true for success, false for failure.

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CloseConnection
boolean CloseConnection();
Introduced in version 9.5.0.70

Forcibly closes the underlying connection. This is a non-clean way to close the connection, but may be used if needed. The clean way to close a websocket is to send a Close frame, and then receive the Close response.

Returns true for success, false for failure.

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GetFrameData
boolean GetFrameData(CkString outStr);
String getFrameData();
Introduced in version 9.5.0.70

Returns the accumulated received frame data as a string. Calling GetFrameData clears the internal receive buffer.

Returns true for success, false for failure.

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GetFrameDataBd
boolean GetFrameDataBd(CkBinData binData);
Introduced in version 9.5.0.70

Returns the accumulated received frame data in a BinData object. The received data is appended to the binData.

Calling this method clears the internal receive buffer.

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GetFrameDataSb
boolean GetFrameDataSb(CkStringBuilder sb);
Introduced in version 9.5.0.70

Returns the accumulated received frame data in a StringBuilder object. The received data is appended to the sb.

Calling this method clears the internal receive buffer.

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LoadTaskCaller
boolean LoadTaskCaller(CkTask task);
Introduced in version 9.5.0.80

Loads the caller of the task's async method.

Returns true for success, false for failure.

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PollDataAvailable
boolean PollDataAvailable();
Introduced in version 9.5.0.70

Check to see if data is available for reading on the websocket. Returns true if data is waiting and false if no data is waiting to be read.

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ReadFrame
boolean ReadFrame();
Introduced in version 9.5.0.70

Reads a single frame from the connected websocket. If a frame was successfuly received, then the following properties are set: FrameOpcode, FrameDataLen, FinalFrame, and the received frame data can be retrieved by calling GetFrameData, GetFrameDataSb, or GetFrameDataBd.

Returns true for success, false for failure.

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ReadFrameAsync (Android™) (Java)
CkTask ReadFrameAsync();
Introduced in version 9.5.0.70

Creates an asynchronous task to call the ReadFrame method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SendClose
boolean SendClose(boolean includeStatus, int statusCode, String reason);
Introduced in version 9.5.0.70

Sends a Close control frame. If includeStatus is true, then the statusCode is sent in the application data part of the Close frame. A Close reason may be provided only if includeStatus is true. If this Close was sent to satisfy an already-received Close frame, then the underlying connection will also automatically be closed.

Note: If a status code and reason are provided, the utf-8 representation of the reason string must be 123 bytes or less. Chilkat will automatically truncate the reason to 123 bytes if necessary. Also, the status code must be an integer in the range 0 to 16383.

The WebSocket protocol specifies some pre-defined status codes at WebSocket Status Codes. For a normal closure, a status code value of 1000 should be used. The reason can be any string, as long as it is 123 bytes or less.

Returns true for success, false for failure.

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SendCloseAsync (Android™) (Java)
CkTask SendCloseAsync(boolean includeStatus, int statusCode, String reason);
Introduced in version 9.5.0.70

Creates an asynchronous task to call the SendClose method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SendFrame
boolean SendFrame(String stringToSend, boolean finalFrame);
Introduced in version 9.5.0.70

Sends a single data frame containing a string. If this is the final frame in a message, then finalFrame should be set to true. Otherwise set finalFrame equal to false.

Returns true for success, false for failure.

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SendFrameAsync (Android™) (Java)
CkTask SendFrameAsync(String stringToSend, boolean finalFrame);
Introduced in version 9.5.0.70

Creates an asynchronous task to call the SendFrame method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SendFrameBd
boolean SendFrameBd(CkBinData bdToSend, boolean finalFrame);
Introduced in version 9.5.0.70

Sends a single data frame containing binary data (the contents of bdToSend). If this is the final frame in a message, then finalFrame should be set to true. Otherwise set finalFrame equal to false.

Returns true for success, false for failure.

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SendFrameBdAsync (Android™) (Java)
CkTask SendFrameBdAsync(CkBinData bdToSend, boolean finalFrame);
Introduced in version 9.5.0.70

Creates an asynchronous task to call the SendFrameBd method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SendFrameSb
boolean SendFrameSb(CkStringBuilder sbToSend, boolean finalFrame);
Introduced in version 9.5.0.70

Sends a single data frame containing a string (the contents of sbToSend). If this is the final frame in a message, then finalFrame should be set to true. Otherwise set finalFrame equal to false.

Returns true for success, false for failure.

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SendFrameSbAsync (Android™) (Java)
CkTask SendFrameSbAsync(CkStringBuilder sbToSend, boolean finalFrame);
Introduced in version 9.5.0.70

Creates an asynchronous task to call the SendFrameSb method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SendPing
boolean SendPing(String pingData);
Introduced in version 9.5.0.70

Sends a Ping control frame, optionally including text data. If pingData is non-empty, the utf-8 representation of the string must be 125 bytes or less. Chilkat will automatically truncate the pingData to 125 bytes if necessary.

Returns true for success, false for failure.

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SendPingAsync (Android™) (Java)
CkTask SendPingAsync(String pingData);
Introduced in version 9.5.0.70

Creates an asynchronous task to call the SendPing method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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SendPong
boolean SendPong();
Introduced in version 9.5.0.70

Sends a Pong control frame. If this Pong frame is sent to satisfy an unresponded-to Ping frame, then the previously received Ping data is automatically sent in this Pong frame.

Returns true for success, false for failure.

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SendPongAsync (Android™) (Java)
CkTask SendPongAsync();
Introduced in version 9.5.0.70

Creates an asynchronous task to call the SendPong method with the arguments provided. (Async methods are available starting in Chilkat v9.5.0.52.)

Note: Async method event callbacks happen in the background thread. Accessing and updating UI elements existing in the main thread may require special considerations.

Returns nil on failure

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UseConnection
boolean UseConnection(CkRest connection);
Introduced in version 9.5.0.70

Initializes the connection for a WebSocket session. All WebSocket sessions begin with a call to UseConnection. A Chilkat REST object is used for the connection because the WebSocket handshake begins with an HTTP GET request. The Chilkat REST API provides the ability to add custom headers, authentication, etc. to the opening GET handshake. It also provides the ability to establish connections over TLS or SSH and to benefit from the rich set of features already present relating to HTTP proxies, SOCKS proxies, bandwidth throttling, IPv6, socket options, etc.

Returns true for success, false for failure.

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ValidateServerHandshake
boolean ValidateServerHandshake();
Introduced in version 9.5.0.70

Called after sending the opening handshake from the Rest object. Validates the server's response to the opening handshake message. If validation is successful, the application may begin sending and receiving data and control frames.

Returns true for success, false for failure.

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Events

Chilkat supports event callbacks in Java (including Android) starting in version 9.5.0.52. To implement an event callback, your application would define and implement a class that derives from CkBaseProgress. Your application can implement methods to override some or all of the default/empty method implementations of the CkBaseProgress base class.

For example:

// Install an event callback handler to get progress events.
MyBaseProgress websocketProgress = new MyBaseProgress();
http.put_EventCallbackObject(websocketProgress);

MyBaseProgress example:

import com.chilkatsoft.CkBaseProgress;
import com.chilkatsoft.CkTask;

public class MyBaseProgress extends CkBaseProgress 
{	
  public boolean AbortCheck()
  {
    System.out.println("AbortCheck");
    // Return true to abort, false to allow the method to continue.
    return false;
  }
  	
  // pctDone is a value from 0 to 100
  // (it is actually value from 0 to the PercentDoneScale property setting)
  public boolean PercentDone(int pctDone)
  {
    System.out.println(pctDone);
    // Return true to abort, false to allow the method to continue.
    // Note: A PercentDone event is the equivalent of an AbortCheck.  
    // When PercentDone events are frequently firing, AbortCheck events are suppressed.
    // AbortCheck events will fire when the time between PercentDone events is longer 
    // than the HeartbeatMs property setting.
    return false;
  }
  
  public void ProgressInfo(String name, String value)
  {
    System.out.println(name + ": " + value);
  }
  
  public void TaskCompleted(CkTask task)
  {
     System.out.println("task completed!");
  }
  
}
AbortCheck
public boolean AbortCheck();

Provides the opportunity for a method call to be aborted. The AbortCheck event is fired periodically based on the value of the HeartbeatMs property. If HeartbeatMs is 0, then no AbortCheck events will fire. As an example, to fire 5 AbortCheck events per second, set the HeartbeatMs property equal to 200. Return true to abort; return false to continue (not abort)

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PercentDone
public boolean PercentDone(int pctDone);

Provides the percentage completed for any method that involves network communications or time-consuming processing (assuming it is a method where a percentage completion can be measured). This event is only fired when it is possible to know a percentage completion, and when it makes sense to express the operation as a percentage completed. The pctDone argument will have a value from 1 to 100. For operations (Chilkat method calls) that complete very quickly, the number of PercentDone callbacks will vary, but the final callback should have a value of 100. For long running operations, no more than one callback per percentage point will occur (for example: 1, 2, 3, ... 98, 99, 100).

The PercentDone callback counts as an AbortCheck event. For method calls that complete quickly such that PercentDone events fire, it may be that AbortCheck events don't fire because the opportunity to abort is already provided in the PercentDone callback. For time consuming operations, where the amount of time between PercentDone callbacks are long, AbortCheck callbacks may be used to allow for the operation to be aborted in a more responsive manner.

Return true to abort; return false to continue (not abort)

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ProgressInfo
public void ProgressInfo(String name, String value);

A general name/value event that provides information about what is happening during a method call. To find out what information is available, write code to handle this event and log the name/value pairs. Most are self-explanatory.

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TaskCompleted
public void TaskCompleted(CkTask task);

Called in the background thread when an asynchronous task completes.

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