ISPRS Workshop on Service and Application of Spatial Data Infrastructure, XXXVi(4/W6), Oct. 14-16, Hangzhou, China 
the same connection for subsequent requests can therefore 
dramatically improve the system performance. A database 
connection pool is a straightforward solution. It creates 
connection objects in main memory initially, and the connection 
object will be reused when a database access is needed. So, the 
frequent create and destroy of database connection is avoided. 
Therefore, the system overall performance is improved. 
7. THE END 
Nowadays, by issuing geographic information through the 
Internet is a main way for people to get geographic information 
service. Application server, as a operation system on Internet, 
provides a modularized method for developers to establish, 
deploy, maintain web application by dividing user interface, 
business logic from back-end service. It also offers a convenient 
using environment for web users and a quick development, high 
flexibility and expandability platform for service provider. The 
model, which based on application server, in this article is an 
ideal model to realize geographic information service. 
REFERENCES 
Fan Guochuang, Zhong Hua, Huang Tao, Yulin Feng. 2003. A 
Survey on Web Application Servers. Journal of software, 
14(10), pp. 1728-1739. 
Qi Xiangming, Hou Di, Qi Yong, Junyi Shen, 2000. 
Architecture of Application Server for CORBA Components. 
Journal of Xi’an Jiaotong University, 34(4), pp. 37-41. 
Qi Yong, Jizhong Zhao, Hou Di, Junyi Shen, Bingyi Zeng, 
2001. Study of Application Server-Web Based Middle Ware 
System Integrated Framework. Journal of Computer Research 
& Development. 38(4), pp. 430-437. 
Wang Jizhou, Juner Fu, Chengming Li, Xianyan Zhu, 2003. 
Research on Constructing J2EE-based WebGIS Application 
Server. Computer Engineering and Application, 28, pp. 36-45. 
Wang Qianxiang, 2003. Theories and Implementation of 
Application Server. Publishing House of Electronics Industry. 
Beijing.