Servlets vs CGI

Servlets vs CGI

Choosing Servlets over CGI has many advantages, but the main ones are:

1. Platform indepencence. As servlets are written in Java only, they can run on any servlet enabled web-server, whatever the platform - Windows, Unix, Linux, etc. For instance, if an online application is developed on a Windows machine with Java web server, it can easily be executed on an Apache web server without further alteration of the code. 

2. Performance. Servlets run a lot faster than CGI scripts. This is due to the fact that once the initialization of a servlet has finished during the first user request, it remains in the server's memory as a single instance. If a new request comes in, it simply starts a new thread. Traditional CGI scripts start a new process every time a request has been received.

3. Extensibility. As Servlets are written in Java, which is a well-designed, robust and objectoriented language, they can be easily transformed into new objects, thus providing ideal solutions in a fast-paced business environment.

4. Security. Servlets adopt Java's well-known security features, such as exception handling, memory management, etc. A servlet can only be executed by a contained within a restrictive environment, called a sandbox, reducing the risk imposed of harmful code.

However, CGI does have its advantages, that have to be taken into consideration. They can be written in more than one language, but practice shows that they are mainly written in perl. They also run in their own OS shell, so they can't cause any concurrency conflicts.