Book Image

Enterprise Application Development with Ext JS and Spring

By : Gerald Gierer
Book Image

Enterprise Application Development with Ext JS and Spring

By: Gerald Gierer

Overview of this book

Spring and Ext JS are cutting edge frameworks that allow us to build high performance web applications for modern devices, that are now consuming data at a faster rate than ever before. It is the appropriate time for you to understand how to best leverage these technologies when architecting, designing, and developing large scale web development projects. This practical guide condenses an approach to web development that was gained from real world projects, and outlines a simple, practical approach to developing high performance, and enterprise grade web applications. Starting with configuring Java, NetBeans, and MySQL to prepare your development environment, you will then learn how to connect your NetBeans IDE to the MySQL database server. We will then explore the Task Time Tracker (3T) project database structure and populate these tables with test data. Following on from this, we will examine core JPA concepts after reverse engineering the domain layer with NetBeans. Leveraging the Data Access Object design pattern, you will learn how to build the Java DAO implementation layer assisted by generics in base classes, followed by a Data Transfer Object enabled service layer to encapsulate the business logic of your 3T application. The final chapters that focus on Java explore how to implement the request handling layer using Spring annotated controllers, and deploy the 3T application to the GlassFish server. We will then configure the Ext JS 4 development environment and introduce key Ext JS 4 concepts, including MVC and practical design conventions. Covering a variety of important Ext JS 4 strategies and concepts, you will be fully-equipped to implement a variety of different user interfaces using the Ext JS MVC design pattern. Your journey ends by exploring the production build and deployment process using Maven, Sencha Cmd and GlassFish.
Table of Contents (22 chapters)
Enterprise Application Development with Ext JS and Spring
Credits
About the Author
Acknowledgments
About the Reviewers
www.PacktPub.com
Preface
Introducing Spring Data JPA
Index

Refactoring Java equals() and hashCode()


Our domain layer entity classes have autogenerated equals and hashCode methods defined. The Company class, for example, defines these methods as shown:

It is best practice to always provide correctly implemented equals and hashCode methods that use the entity ID to calculate the value that is returned. These methods are used by JPA to determine the equality between entities. Our autogenerated equals method will work correctly with JPA as the ID entity is used in the comparison for each method. However, the //TODO: Warning message on line 83 (see the previous screenshot) indicates an issue that can be avoided if we regenerate the equals method with the NetBeans IDE.

Delete the equals method and right-click on the Company.java file in the editor using the mouse to display the context menu. Select the Insert Code… option:

From the pop-up menu, select the equals()… option and ensure that the idCompany : Integer field is selected in the Generate equals(...