Spring创建Bean完成后执行指定代码的几种实现方式

@Component
public class DoByApplicationListener implements ApplicationListener<ContextRefreshedEvent> {
    public DoByApplicationListener() {
        System.out.println("DoByApplicationListener constructor");
    }
    @Override
    public void onApplicationEvent(ContextRefreshedEvent event) {
        if (event.getApplicationContext().getParent() == null) {
            System.out.println("DoByApplicationListener do something");
        }
    }
}

@Component
public class DoByInitializingBean implements InitializingBean {
    public DoByInitializingBean() {
        System.out.println("DoByInitializingBean constructor");
    }
    @Override
    public void afterPropertiesSet() throws Exception {
        System.out.println("InitByInitializingBean do something");
    }
}

@Component
public class DoByPostConstructAnnotation {
    public DoByPostConstructAnnotation() {
        System.out.println("DoByPostConstructAnnotation constructor");
    }
    @PostConstruct
    public void init(){
        System.out.println("InitByPostConstructAnnotation do something");
    }
}