大致说一下spring bean的生命周期

面试1、实例化 Bean2、给 Bean 属性赋值3、初始化 Bean4、使用 Bean5、销毁 Beanpackagecom.example.demo.bean;importjakarta.annotation.PostConstruct;importjakarta.annotation.PreDestroy;importorg.springframework.beans.factory.annotation.Value;importorg.springframework.stereotype.Component;ComponentpublicclassUser{privateStringusername;publicUser(){System.out.println(第一步实例化 Bean构造方法执行);}Value(zhangsan)publicvoidsetUsername(Stringusername){System.out.println(第二步给 Bean 属性赋值);this.usernameusername;}PostConstructpublicvoidinitBean(){System.out.println(第三步初始化 Bean);}PreDestroypublicvoiddestroyBean(){System.out.println(第五步销毁 Bean);}OverridepublicStringtoString(){returnUser{usernameusername};}}packagecom.example.demo;importcom.example.demo.bean.User;importorg.springframework.boot.SpringApplication;importorg.springframework.boot.autoconfigure.SpringBootApplication;importorg.springframework.context.ConfigurableApplicationContext;SpringBootApplicationpublicclassDemoApplication{publicstaticvoidmain(String[]args){ConfigurableApplicationContextcontextSpringApplication.run(DemoApplication.class,args);Userusercontext.getBean(User.class);System.out.println(第四步使用 Beanuser);context.close();}}