@Component
public class FirstInitialization {

    @PostConstruct
    public void init(){
        System.out.println("我是第一個(gè)加載！");
    }

}

@Component
@DependsOn("firstInitialization")
public class SecondInitialization {

    @PostConstruct
    public void init(){
        System.out.println("我是第二個(gè)加載！");
    }

}

@Component
@DependsOn("secondInitialization")
public class ThirdInitialization {

    @PostConstruct
    public void init(){
        System.out.println("我是第三個(gè)加載！");
    }

}

@Component
@DependsOn("thirdInitialization")
public class ForthInitialization {

    @PostConstruct
    public void init(){
        System.out.println("我是第四個(gè)加載！");
    }

}

public class MyApplicationContextInitializer implements ApplicationContextInitializer {
    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {

        //將自定義的BeanFactoryPostProcessor實(shí)現(xiàn)類保存到ApplicationContext中
        applicationContext.addBeanFactoryPostProcessor(new MyBeanFactoryPostProcessor());
    }
}

/**
 * BeanFactoryPostProcessor的子類
 * 允許開發(fā)人員在Bean定義注冊(cè)之前和之后對(duì)BeanDefinition進(jìn)行自定義處理，例如添加，修改或刪除Bean定義等。
 */
public class MyBeanFactoryPostProcessor implements BeanDefinitionRegistryPostProcessor {

    // 初始化需要排序的類，這里要保證插入順序只能用LinkedHashMap
    private static final Map<String, Class> ORDER_BEAN_MAP = new LinkedHashMap<>() {
        {
            put("firstInitialization", FirstInitialization.class);
            put("secondInitialization", SecondInitialization.class);
            put("thirdInitialization", ThirdInitialization.class);
            put("forthInitialization", ForthInitialization.class);
        }
    };

    @Override
    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
        Optional.ofNullable(ORDER_BEAN_MAP.keySet()).orElse(new HashSet<>()).stream()
                .forEach(beanName -> {
                    // 初始化一個(gè) Bean 定義
                    AbstractBeanDefinition beanDefinition = BeanDefinitionBuilder
                            .genericBeanDefinition().getBeanDefinition();

                    // 按順序注冊(cè)每個(gè)Bean
                    beanDefinition.setBeanClass(ORDER_BEAN_MAP.get(beanName));
                    registry.registerBeanDefinition(beanName, beanDefinition);
                });
    }
}