March 2014
Intermediate to advanced
936 pages
29h 2m
English
Content preview from Professional Java for Web Applications
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Chapter 5Maintaining State Using Sessions
- Why sessions are necessary
- Working with cookies and URL parameters
- How to store data in a session
- Making sessions useful
- How to cluster an application that uses sessions
WROX.COM CODE DOWNLOADS FOR THIS CHAPTER
You can find the wrox.com code downloads for this chapter at www.wrox.com/go/projavaforwebapps on the Download Code tab. The code for this chapter is divided into the following major examples:
- Shopping-Cart Project
- Session-Activity Project
- Customer-Support-v3 Project
NEW MAVEN DEPENDENCIES FOR THIS CHAPTER
There are no new Maven dependencies for this chapter. Continue to use the Maven dependencies introduced in all previous chapters.
UNDERSTANDING WHY SESSIONS ARE NECESSARY
So far you’ve learned about web applications, web containers, Servlets, JSPs, and how Servlets and JSPs work together. You have also learned about the life cycle of a request, and it should be clear at this point that the tools you have been introduced to so far do not enable you to associate multiple requests coming from the same client and share data between those requests. You might think that you can use the IP address as a unique identifier and all requests from an IP address within some timeframe must belong to the same client. Unfortunately, due to Network Address Translation (NAT) this is not reliable. Thousands of students at a college campus can literally all use the same IP address, hidden behind a NAT router. For this reason ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.