In the Feb 98 issue of JDJ , I presented you with a 3-tier database application that used Java servlets. I will focus on the concepts and techniques of applets communicating with servlets. The article will build on the 3-tier application presented in the previous article. However, if you are a newcomer and missed the previous article, don't worry because I'll give a review of the application. The application allows a public speaker to keep track of students who attends her seminars.
Students interact with the application by entering their contact information into an HTML form.
Once the form is submitted then the Java servlet uses JDBC to store the student information in a database. Afterwards, an updated student list is generated by the servlet and returned as an HTML page to the user. Figure 1 illustrates the three-tier design. The first tier is a web browser, which serves as our universal client. The HTML approach was taken because it lowered the requirements of the client's web browser version.