Instantiating the Spring Container by Using AnnotationConfigApplicationContext

This versatile ApplicationContext implementation is capable of accepting not only @Configuration classes as input but also plain @Component classes and classes annotated.

Spring’s AnnotationConfigApplicationContext introduced in Spring 3.0.


When @Configuration classes are provided as input, the @Configuration class itself is registered as a bean definition and all declared @Bean methods within the class are also registered as bean definitions.

When @Component and JSR-330 classes are provided, they are registered as bean definitions, and it is assumed that DI metadata such as @Autowired or @Inject are used within those classes where necessary.

Simple Construction
In much the same way that Spring XML files are used as input when instantiating a ClassPathXmlApplicationContext, you can use @Configuration classes as input when instantiating an AnnotationConfigApplicationContext. This allows for completely XML-free usage of the Spring container, as the following example shows:

public static void main(String[] args) {
    ApplicationContext ctx = new AnnotationConfigApplicationContext(AppConfig.class);
    MyService myService = ctx.getBean(MyService.class);
    myService.doStuff();
}

As mentioned earlier, AnnotationConfigApplicationContext is not limited to working only with @Configuration classes. Any @Component or JSR-330 annotated class may be supplied as input to the constructor, as the following example shows:

public static void main(String[] args) {
    ApplicationContext ctx = new AnnotationConfigApplicationContext(MyServiceImpl.class, Dependency1.class, Dependency2.class);
    MyService myService = ctx.getBean(MyService.class);
    myService.doStuff();
}

The preceding example assumes that MyServiceImpl, Dependency1, and Dependency2 use Spring dependency injection annotations such as @Autowired.

Building the Container Programmatically by Using register(Class<?>…​)
You can instantiate an AnnotationConfigApplicationContext by using a no-arg constructor and then configure it by using the register() method. This approach is particularly useful when programmatically building an AnnotationConfigApplicationContext. The following example shows how to do so:

public static void main(String[] args) {
    AnnotationConfigApplicationContext ctx = new AnnotationConfigApplicationContext();
    ctx.register(AppConfig.class, OtherConfig.class);
    ctx.register(AdditionalConfig.class);
    ctx.refresh();
    MyService myService = ctx.getBean(MyService.class);
    myService.doStuff();
}