Java Servlets

A Java servlets is Java code that is executed on the server. Usually servlets get their input from HTML forms which have been loaded onto the user's browser. Servlets generate HTML, so the result is always a web page, which can of course contain (as these are HTML elements) tables, pictures, sound, ...

Servlets are often used in connection with large databases, and contain the "business logic" of the application. In order to run servlets, the server must usually be configured as a Java Application Server. Application servers can be acquired from many different companies.

A standard example of a servlet is an application to show stock quotes. The user chooses a stock from a list in an HTML form, chooses extra options, and clicks "SUBMIT". The servlet on the server picks up these options, gets the stock quotes from a database, transforms the data into a graph which is converted to a GIF-image, and this GIF-image is then displayed with additional data in an HTML page which is send to the user.

Computer Chemistry Consultancy, June 2001