Book Image

Spring Data

By : Petri Kainulainen
Book Image

Spring Data

By: Petri Kainulainen

Overview of this book

Spring Framework has always had a good support for different data access technologies. However, developers had to use technology-specific APIs, which often led to a situation where a lot of boilerplate code had to be written in order to implement even the simplest operations. Spring Data changed all this. Spring Data makes it easier to implement Spring-powered applications that use cloud-based storage services, NoSQL databases, map-reduce frameworks or relational databases. "Spring Data" is a practical guide that is full of step-by-step instructions and examples which ensure that you can start using the Java Persistence API and Redis in your applications without extra hassle. This book provides a brief introduction to the underlying data storage technologies, gives step-by-step instructions that will help you utilize the discussed technologies in your applications, and provides a solid foundation for expanding your knowledge beyond the concepts described in this book. You will learn an easier way to manage your entities and to create database queries with Spring Data JPA. This book also demonstrates how you can add custom functions to your repositories. You will also learn how to use the Redis key-value store as data storage and to use its other features for enhancing your applications. "Spring Data" includes all the practical instructions and examples that provide you with all the information you need to create JPA repositories with Spring Data JPA and to utilize the performance of Redis in your applications by using Spring Data Redis.
Table of Contents (13 chapters)

Loading the application context configuration

The old way to load the application context configuration of our application is to use the web application deployment descriptor file, which is more commonly known as web.xml. However, because we are using the Spring Framework 3.1 in a Servlet 3.0 environment, we can create a web application configuration class by implementing the WebApplicationInitializer interface. This ensures that Spring Framework automatically detects our configuration class when a servlet container is started.

We will use our web application configuration class to:

  1. Load our application context configuration class.

  2. Configure the dispatcher servlet.

  3. Create the context loader listener and add it to our servlet context.

The source code of our configuration class is given as follows:

public class DataJPAExampleInitializer implements WebApplicationInitializer {
    public void onStartup(ServletContext servletContext) throws ServletException {