Package com.facilita.fc.web

Class WebSocketMessageQueue

java.lang.Object

com.facilita.fc.web.WebSocketMessageQueue

public class WebSocketMessageQueue
extends java.lang.Object

Provides a mechanism for waiting for WebSocketMessage's to arrive from the server.

As soon as a WebSocket is opened, the server can start sending messages to the client. It is often necessary to wait for a particular message to arrive from the server before the script can continue. This class provides an easy way to wait for a message to arrive.

The following example demonstrates waiting for a message to arrive from the server.

 Url url = new Url("ws://somecompany.com/");
 WebSocket webSocket = getWebBrowser().createWebSocket(url, 1);
 webSocket.open();
  
 // Create a message queue
 WebSocketMessageQueue messageQueue = new WebSocketMessageQueue(webSocket);
  
 // Wait for the "ready" message to arrive from the server, waiting up to 30 seconds between messages.
 WebSocketMessage message = messageQueue.waitForMessageContaining("ready", 30000);
 

Constructor Summary

Constructors

Constructor	Description
WebSocketMessageQueue(WebSocket webSocket)	Creates a new WebSocketMessageQueue instance to wait for messages on a particular WebSocket.

Method Summary

Modifier and Type	Method	Description
WebSocketMessage	getNextMessage(long timeout)	Get the next WebSocketMessage in the queue.
WebSocketMessage	waitForMessageContaining(java.lang.String text, long perMessageTimeout)	Wait for a WebSocketMessage containing a specific piece of text to arrive from the server.

Methods inherited from class java.lang.Object

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

Constructor Detail

WebSocketMessageQueue

public WebSocketMessageQueue(WebSocket webSocket)

Creates a new WebSocketMessageQueue instance to wait for messages on a particular WebSocket.

Parameters:

webSocket - The WebSocket that this queue will receive messages from.

Method Detail

getNextMessage

public WebSocketMessage getNextMessage(long timeout)
                                throws java.lang.InterruptedException,
                                       com.facilita.exception.TimeoutException

Get the next WebSocketMessage in the queue. If the queue is empty, wait for up to timeout milliseconds for a message to arrive.

Parameters:

timeout - The maximum number of milliseconds to wait for a message to arrive from the server.

Returns:

The next WebSocketMessage in the queue.

Throws:

java.lang.InterruptedException - if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.

com.facilita.exception.TimeoutException - No message arrived from the server before the timeout period elapsed.

waitForMessageContaining

public WebSocketMessage waitForMessageContaining(java.lang.String text,
                                                 long perMessageTimeout)
                                          throws com.facilita.exception.TimeoutException,
                                                 java.lang.InterruptedException,
                                                 java.lang.Exception

Wait for a WebSocketMessage containing a specific piece of text to arrive from the server.

Parameters:

text - The text to look for in each WebSocketMessage.

perMessageTimeout - The maximum number of milliseconds to wait for each message to arrive from the server.

Returns:

The first message to arrive from the server WebSocketMessage that contains text.

Throws:

com.facilita.exception.TimeoutException - No message arrived from the server before the perMessageTimeout period elapsed.

java.lang.InterruptedException - if any thread has interrupted the current thread. The interrupted status of the current thread is cleared when this exception is thrown.

java.lang.Exception - An error occurred