摘要：The paper researched and realized the initiative message transmission mechanism of WEBGIS server based on the N layer architecture of Internet. According to WEBGIS application long business operation as well as server information visualized in client side in real-time features, this article uses the Socket communication and the client side with JAVA Applet to realize that the WEB server can send message initiative to the client. It comes up and realizes a concrete plan of initiative transmission mechanism in WEBGIS. We run the realization plan based on Winsock through the project practice of Guangzhou cable TV network security monitoring and alarm system. The system operation has been verified in system running. The combination of this mechanism with conventional WEBGIS can greatly improve the performance and the usability of WEBGIS.
