Definition - What does Java Servlet mean?
Java Servlets are server-side Java program modules that process and answer client requests and implement the servlet interface. It helps in enhancing Web server functionality with minimal overhead, maintenance and support.
A servlet acts as an intermediary between the client and the server. As servlet modules run on the server, they can receive and respond to requests made by the client. Request and response objects of the servlet offer a convenient way to handle HTTP requests and send text data back to the client.
Since a servlet is integrated with the Java language, it also possesses all the Java features such as high portability, platform independence, security and Java database connectivity.
Techopedia explains Java Servlet
There are two Java Servlet types: Basic and HTTP.
HTTP servlets are used as follows:
- When an HTML form is submitted, the servlet processes and stores the data.
- When a client supplies a database query, the results are provided to the client by the servlet.
- In most cases, the server uses the common gateway interface (CGI).
However, Java Servlets have many advantages over CGI, including:
- A servlet runs in the same process, eliminating the need to create a new process for every request.
- The CGI program must be reloaded for each CGI request. A servlet, however, does not require reloading and remains in the memory between requests.
- A servlet answers multiple requests simultaneously by using one instance, saving memory and easily managing persistent data.
- The servlet engine runs in a sandbox or restricted environment, protecting the server from potentially harmful servlets.