springboot启动过程中常用的回调示例详解

public class MyApplicationContextInitializer implements ApplicationContextInitializer<ConfigurableApplicationContext> {
    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        System.out.println("MyApplicationContextInitializer启动。。。。。。。。。。");
    }
}

@SpringBootApplication
public class Application {

    public static void main(String[] args) {
        SpringApplication springApplication = new SpringApplication(Application.class);
        springApplication.addInitializers(new MyApplicationContextInitializer());
        springApplication.run(args);
        //SpringApplication.run(Application.class, args);
    }
}

@Component
public class MyApplicationListener implements ApplicationListener<ContextRefreshedEvent> {
    @Override
    public void onApplicationEvent(ContextRefreshedEvent contextRefreshedEvent) {
        System.out.println("MyApplicationListener。。。。。。。。。。");
    }
}

ublic class MyApplicationRunner implements ApplicationRunner {
    @Override
    public void run(ApplicationArguments args) throws Exception {
        System.out.println("MyApplicationRunner。。。。。。。。。。");
    }
}
源码：
/**
 *用于指示 bean 包含在SpringApplication时应该运行的SpringApplication
 *多个ApplicationRunner bean 可以在同一个应用程序上下文中定义，并且可以使用Ordered接口或@Order注释进行排序。
 */
public interface ApplicationRunner {
	/**
	 * 传入的应用程序参数
	 */
	void run(ApplicationArguments args) throws Exception;
}

@Component
public class MyCommandLineRunner implements CommandLineRunner {

    @Override
    public void run(String... args) throws Exception {
        System.out.println("MyCommandLineRunner。。。。。。。。。。");
    }

}