Common Web Application Technologies

Introduction Modern web applications are rarely built with a single technology. A typical application combines a web server, a programming language, a framework, a database, data formats, and backend services to deliver its functionality. For anyone learning web application security, it’s important to understand these technologies at a basic level—not only to recognize them, but to understand where they sit in the architecture, how data moves through the system, and where weaknesses can be introduced. This article covers: Java Platform ASP.NET PHP Ruby on Rails SQL XML Web Services & SOAP Web Application Architecture: The Big Picture You can think of a web application as a pipeline: User (Browser) ↓ Web Server / App Server ↓ Application Code ↓ Database / Backend Services ↓ Response back to Browser A useful security question to keep in mind: Once user input enters the application, where does it go, how is it processed, and is it handled safely? 1) The Java Platform (Enterprise Web Applications) Java is widely used for large-scale enterprise applications. Java-based web apps can run on operating systems such as Windows, Linux, and Solaris and can use different application servers, frameworks, and third-party components. Simplified Flow Browser ↓ HTTP Request ↓ Java Web Container ↓ Java Application ↓ Database / Other Services ↓ HTTP Response Common Java Terms (Quick Explanations) Enterprise Java Bean (EJB) An Enterprise Java Bean is a relatively heavyweight Java component that encapsulates the logic of a particular business function. It can also handle enterprise requirements such as transaction management. Plain Old Java Object (POJO) POJO stands for Plain Old Java Object —a regular Java object rather than a specialized component like an EJB. POJOs are typically simpler and more lightweight, which is why they are common in modern Java applications. Java Servlet A Java Servlet is a Java component that receives HTTP requests and returns HTTP responses. In many Java web