WWW, a popular internet tool, is a distributed hypermedia system. It is created to share the information in the academic research. With its development, WWW is applied to business affairs and needed to realize many other funtions, such as the direct deal on the web, the personnel salary management, stock management and so on. It is very hard to realize them only using WWW technique. What's more, WWW managed the datas by means of directories and files. So it often can not find the needed information very effectively. However, database system is just designed to manage and inquire the data and very suitable to be applied to the business application. Although it has developed from Mainframe to Client/Server, database system still faces with a series of problems. WWW appeals to the database developer. The WWW browser is very easy to learn and use. The developer will not consider the hardware platform of client if the client computer is connected to internet. Moreover, WWW can display many types of data, which is more suitable to the requirement of database systems. So it is a certain trend to combine the database systems with WWW. There are few examples of connecting database systems and WWW successfully in China. The research in the field is also just underway in China. The dissertation is divided into two parts. In the first part I divide the technique of connecting the database systems with WWW into four methods, study every method, and summarize their advantages and drawbacks. At last I summarize the principle of choosing the methods. In second part I propose a new method, using Java Applet to connect WWW with database. Generally Java Applet can use JDBC API to access the databases. Because JDBC API is uniform, database independent and used to access many types of databases. But because of its own limitations, Java Applet can not call some kind of driver to access the relative databases. Moreover, the database vendors have not all provided JDBC the drivers. So the dissertation do the further research, proposing another method which can access the databases that Java Applet using the JDBC can not access. That is to use a three-tie architecture, in which a standalone Java server is used as a gateway server. It communicates as a server with the Java Applet at one end in user-defined protocols, while accessing the database server at the other end in the native client/server protocols. Between the Java Applet and Gateway Server, we can use a software tool called Horb. Horb provides a high level abstraction with all socket interfaces encapsulated within the Horb. A developer only needs to deal with application level objects. Thus through the combination of the above two methods, we realize a complete mechanism of using Java Applet to access the databases.
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