Book Image

Spring Essentials

Book Image

Spring Essentials

Overview of this book

Spring is an open source Java application development framework to build and deploy systems and applications that run on the JVM. It is the industry standard and the most popular framework among Java developers with over two-thirds of developers using it. Spring Essentials makes learning Spring so much quicker and easier with the help of illustrations and practical examples. Starting from the core concepts of features such as inversion of Control Container and BeanFactory, we move on to a detailed look at aspect-oriented programming. We cover the breadth and depth of Spring MVC, the WebSocket technology, Spring Data, and Spring Security with various authentication and authorization mechanisms. Packed with real-world examples, you’ll get an insight into utilizing the power of Spring Expression Language in your applications for higher maintainability. You’ll also develop full-duplex real-time communication channels using WebSocket and integrate Spring with web technologies such as JSF, Struts 2, and Tapestry. At the tail end, you will build a modern SPA using EmberJS at the front end and a Spring MVC-based API at the back end.By the end of the book, you will be able to develop your own dull-fledged applications with Spring.
Table of Contents (14 chapters)
Spring Essentials
Credits
About the Authors
About the Reviewer
www.PacktPub.com
Preface
Index

Handling exceptions in the Spring Data layer


With traditional JDBC-based applications, exception handling is based on java.sql.SQLException, which is a checked exception. It forces the developer to write catch and finally blocks carefully for proper handling and to avoid resource leakages such as leaving a database connection open. Spring, with its smart exception hierarchy based on RuntimeException, spares the developer from this nightmare. Having DataAccessException as the root, Spring bundles a bit set of meaningful exceptions, translating the traditional JDBC exceptions. Spring also covers Hibernate, JPA, and JDO exceptions in a consistent manner.

Spring uses SQLErrorCodeExceptionTranslator, which inherits SQLExceptionTranslator for translating SQLException to DataAccessExceptions. We can extend this class to customize the default translations. We can replace the default translator with our custom implementation by injecting into the persistence resources (such as JdbcTemplate, to be...