Pre-requisite – Introduction to Servlet
Servlets are the Java programs that run on the Java-enabled web server or application server. They are used to handle the request obtained from the webserver, process the request, produce the response, then send the response back to the webserver. Below are some alternatives to servlets:
1. Common Gateway Interface (CGI)
It is the most typical server-side solution. CGI application is an independent program that receives requests from the online server and sends it back to the webserver. The use of CGI scripts was to process forms. it’s the technology that permits web browsers to submit forms and connect with programs over an internet server. The common gateway interface provides an even way for data to be passed from the user’s request to the appliance program and back to the user.
Example: When you fill-up the shape and submit the shape applying, click the submit button and it goes, what are the results from this level is CGI.
A common problem in this when a new process is created every time the web server receives a CGI request so it results in a delay of response time.
2. Proprietary API
Many proprietary web servers have built-in support for server-side programming. These also are called non-free software, or closed-source software, is computer software that the software’s publisher or another person retains property right usual copyright of the ASCII text file, but sometimes patent rights. It’s a software library interface “specific to at least one device or, more likely to a variety of devices within a specific manufacturer’s product range”. The motivation for employing a proprietary API is often vendor lock-in or because standard APIs don’t support the device’s functionality.
Examples: Netscape’s NSAPI, Microsoft’s ISAPI, and O’Reilly’s WSAPI.
Drawback: Most of these are developed in C/C++ and hence can contain memory leaks and core dumps that can crash the webserver.
3. Active Server Pages (ASP)
Microsoft’s ASP is another technology that supports server-side programming. Only Microsoft’s Internet Information Server (IIS) supports this technology which isn’t free. They work with simple HTML pages, the client (a web surfer) requests an internet page from a server. The server just sends the file to the client, and therefore the page is shown on the client’s browser. ASP is now obsolete and replaced with ASP.NET. ASP.NET may be a compiled language and relies on the .NET Framework, while ASP is strictly an interpreted language.
4. Serverside JavaScript
It is another alternative to servlets. The sole known servers that support it are Netscape’s Enterprise and FastTrack servers. This ties you to a specific vendor. Server-side JavaScript can be a JavaScript code that runs over a server local resources and it is similar to Java or C#, but the syntax is predicated on JavaScript.
Example: An ideal of this is often Node.JS. The advantage of server-side scripting is that the ability to highly customize the response supported the user’s requirements, access rights, or queries into data stores.
