Dependency injection pattern with Java-based configuration

As of Spring 3.0, it provides a Java-based Spring configuration to wire the Spring beans. Take a look at the following Java configuration class (AppConfig.java) to define the Spring bean and their dependencies. The Java-based configuration for dependency injection is a better choice, because it is more powerful and type-safe.

Creating a Java configuration class - AppConfig.java

Let's create an AppConfig.java configuration class for our example:

    package com.packt.patterninspring.chapter4.bankapp.config; 
    import org.springframework.context.annotation.Configuration; 
    @Configuration 
    public class AppConfig { 
         //.. 
    } 

The preceding AppConfig class is annotated with the @Configuration annotation, which indicates that it is a configuration class of the application that contains the details on bean definitions. This file will be loaded by the Spring application context to create beans for your application.

Let's...