Metody udržování stavových informací v protokolu HTTP

Interactive Web applications affect almost everyone of us. Communication in these applications is generally provided by HTTP protocol. This protocol is stateless, which means, that it doesn't recognize the relationship between individual transactions. In modern Web applications, however, maintaining the status is crucial to ensure functionality. This thesis deals with various methods of state transmission and storage which solve the fact, that HTTP is stateless. The first part describes a theoretical basis of the HTTP protocol, concerns history of the protocol and explains related concepts. Next chapter deals with proxy and cache servers that serve as mediators in the communication and outlines potential problems that can occur while transferring state information. The following section is devoted to the methods for the maintenance and transmission of state information. In this chapter I describe various methods, then I compare them and discuss potential difficulties. In the next chapter I present the possibilities of the implementation of those methods in different development environments. Given that the matter of security nowadays has the focus, I also look at several problems also from the angle of security and safety. Theoretical conclusions of this thesis are reflected in the enclosed web application, which practically demonstrates the discussed issues and proves that the author of this thesis not only understands those issues, but he is also able to apply them practically.