Book Image

Jakarta EE Cookbook - Second Edition

By : Elder Moraes
Book Image

Jakarta EE Cookbook - Second Edition

By: Elder Moraes

Overview of this book

Jakarta EE is widely used around the world for developing enterprise applications for a variety of domains. With this book, Java professionals will be able to enhance their skills to deliver powerful enterprise solutions using practical recipes. This second edition of the Jakarta EE Cookbook takes you through the improvements introduced in its latest version and helps you get hands-on with its significant APIs and features used for server-side development. You'll use Jakarta EE for creating RESTful web services and web applications with the JAX-RS, JSON-P, and JSON-B APIs and learn how you can improve the security of your enterprise solutions. Not only will you learn how to use the most important servers on the market, but you'll also learn to make the best of what they have to offer for your project. From an architectural point of view, this Jakarta book covers microservices, cloud computing, and containers. It allows you to explore all the tools for building reactive applications using Jakarta EE and core Java features such as lambdas. Finally, you'll discover how professionals can improve their projects by engaging with and contributing to the community. By the end of this book, you'll have become proficient in developing and deploying enterprise applications using Jakarta EE.
Table of Contents (14 chapters)

Preparing your application to use a connection pool

One of the first things we should learn in our lives, after feeding, is how to use a connection pool – especially when we are talking about databases. That's the case here.

Why? Because a connection opened with a database is costly in terms of the resources used for it. If we look closely at the process of opening a new connection, we see that it uses a lot of CPU resources, for example.

Maybe it won't make much of a difference if you have two users using a database with a couple of registers in a few tables. But it can start causing trouble if you have dozens of users, or if the database is large and gives you sleepless nights when you have hundreds of users using a huge database.

Actually, I myself saw in the early days of J2EE 1.3 (the year was 2002) a performance issue being solved by a connection pool in...