The Comet-Based Implementation of Real-Time Drawing Board

Abstract

Comet technique can transfer web data from a client to another in real-time, with the comet server as the message freight station. Using this technology to transfer messages has real-time and efficient advantages. In this paper, a web version real-time share drawing system is designed and implemented, according to the comet server push technology. This system support to transmit drawing information between users, and support a large number of concurrent access. The development in the client side use the flex technology and the system adopts ajax to request and send data. In the server side, system use java to develop service program, and the system is deployed on the tomcat server. Index Terms - comet, flex, ajax, drawing board Summary Traditional drawing board is divided into two, one is based on the c / s architecture which needs to be installed before use, the other is based on media stream technology. However, the real-time sharing drawing board of the b / s structure is blank. With the extensive use of web application development, more and more users make such a demand that they hope to use a web-based real-time shared drawing board, making the drawing board combined with the existing web products tightly. When the user browse the webpage, they can use the drawing board at the same time , without having to install any software. As the comet technology is more and more mature, it is possible to realize such a system. Although the Ajax technology can make internet applications faster and more friendly, the real-time shared drawing board in the b/s architecture need to transmit the changed information in the background to the client without the customer-side non-stop to refresh and send request. The comet server push technology can be a good solution to this problem. Comet technology, the server does not passively wait for user requests, but initiatively send the message to the client, and the client need not too often to send the request to the server to obtain information. So that the server can take the initiative to pass information to customers, and this technology has immediate, efficient, good performance and able to support a large number of users advantages.