Book Image

Enterprise Application Development with Ext JS and Spring

By : Gierer
Book Image

Enterprise Application Development with Ext JS and Spring

By: 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 (16 chapters)
14
A. Introducing Spring Data JPA
15
Index

Defining the DAO interfaces


An interface in the Java programming language defines a set of method signatures and constant declarations. Interfaces expose behaviors (or what can be done) and define a contract that implementing classes promise to provide (how it is done). Our DAO layer will contain one interface and one implementing class per domain object.

Note

The use of interfaces is an often misunderstood pattern in enterprise programming. The argument goes along the line, "Why add another set of Java objects to your codebase when they are not required". Interfaces do add to the number of lines of code that you write, but their beauty will be appreciated as soon as you are asked to refactor an aging project that was written with interfaces from the start. I have migrated an SQL-based persistence layer to a JPA persistence layer. The new DAO implementation replaced the old without any significant change in the service layer, thanks to the use of interfaces. Development was done in parallel...