In this chapter, we will program a web application. We will build on what we have achieved already and create a web version of the Mastermind game. This time, it will not only run alone, guessing and answering the number of positions and matched colors, but also communicate with the user asking for the answers to the guesses. This will be a real game. Web programming is extremely important for Java programmers. Most of the programs are web applications. The universal client available on the Internet is the web browser. The thin-client, web browser-based architecture is widely accepted in enterprises as well. There are only some exceptions when the architecture has something else but the web client. If you want to become a professional Java developer, you must be familiar with web programming. And it is also fun!

There are a lot of technical topics that we will visit during the development. First of all, we will discuss networking...