从Spring 3起，JavaConfig功能已经包含在Spring核心模块，它允许开发者将bean定义从在Spring配置XML文件转移到Java类中。

1.Bean

@Configuration
public class AppConfig {
    
    @Bean(name="helloBean")
    public HelloWorld helloWorld() {
        return new HelloWorldImpl();
    }
    
}

2.Dao

public interface HelloWorld {
    
    void printHelloWorld(String msg);
 
}

3.Service

public class HelloWorldImpl implements HelloWorld {

    @Override
    public void printHelloWorld(String msg) {

        System.out.println("Hello : " + msg);
    }

}

4.执行结果

public class App {
    public static void main(String[] args) {
        
            ApplicationContext context = new AnnotationConfigApplicationContext(AppConfig.class);
        HelloWorld obj = (HelloWorld) context.getBean("helloBean");
        
        obj.printHelloWorld("Spring Java Config");

    }
}

5.@Import示例

@Configuration
@Import({ CustomerConfig.class, SchedulerConfig.class })
public class AppConfig {

}