标签：nal ebean efault proc 引用 3.0 factor cap 接口
目录
参考链接1：Spring中Bean的生命周期是怎样的？
参考链接2：Spring Bean 生命周期
最近买了几本书，看了其中讲springboot的一本书，看到了讲spring bean的生命周期这一节，书上只是提了个大概，感觉不是自己想要的结果，还是自己动手吧；虽然写得不好，但是记一记还是对自己有好处的；
在网上找了几张图，感觉有一张比较清楚：
接下来说一下几种方式吧，该项目使用springboot构建的；以下代码均在改项目中完成
新建一个bean类,注意该bean类上并没有使用注解
public class CustomBean {
private final static Logger logger = LoggerFactory.getLogger(CustomBean.class);
public void init(){
logger.info("CustomBean-init");
}
public void destroy(){
logger.info("CustomBean-destroy");
}
}自定义bean的初始化和销毁方法需要在配置文件中添加以下代码：
@Configuration
public class LifeCycleConfig {
/**
* 自定义bean的initMethod和destroyMethod
* @return
*/
@Bean(initMethod = "init",destroyMethod = "destroy")
CustomBean customBean(){
return new CustomBean();
}
}
使用@PostConstruct和@PreDestroy两个注解，其中 @PostConstruct是在构方函数执行完之后指向性，@PreDestroy是在bean销毁前执行；
该bean类上使用了Component注解,当然，你还可以使用另外的那三个注解中的某一个；
@Component
public class AnnotationBean {
private static final Logger logger= LoggerFactory.getLogger(AnnotationBean.class);
@PostConstruct
public void init(){
logger.info("AnnotationBean-init");
}
@PreDestroy
public void destroy(){
logger.info("AnnotationBean-destroy");
}
}还可以继承InitializingBean, DisposableBean接口
@Component
public class LifeCycleBean implements InitializingBean,DisposableBean {
private static final Logger logger= LoggerFactory.getLogger(LifeCycleBean.class);
@Override
public void destroy() throws Exception {
logger.info("LifeCycleBean-destroy");
}
@Override
public void afterPropertiesSet() throws Exception {
logger.info("LifeCycleBean-afterPropertiesSet");
}
}在上边的图中可看见，有三个在最前面的三个Aware接口类，这些接口的功能就不用去说了
@Component
public class LifeCycleBeanAware implements BeanNameAware,BeanFactoryAware,ApplicationContextAware {
private static final Logger logger= LoggerFactory.getLogger(LifeCycleBeanAware.class);
@Override
public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
logger.info("bean工厂");
}
@Override
public void setBeanName(String s) {
logger.info("bean的默认的名字："+s);
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
logger.info("bean上下文");
}
}这个类不是接口类，这个类中有两个方法postProcessBeforeInitialization和postProcessAfterInitialization
@Component
public class LifeCycleProcessor implements BeanPostProcessor {
private static final Logger logger= LoggerFactory.getLogger(LifeCycleProcessor.class);
private static final String DEFAULT_BEAN_NAME="annotationBean";
/**
*在bean初始化之前执行
* @param bean
* @param beanName
* @return
* @throws BeansException
*/
@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
if(DEFAULT_BEAN_NAME.equals(beanName)){
logger.info("bean初始化之前执行："+beanName);
}
return bean;
}
/**
*bean初始化之后执行
* @param bean
* @param beanName
* @return
* @throws BeansException
*/
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
if(DEFAULT_BEAN_NAME.equals(beanName)){
logger.info("bean初始化之后执行："+beanName);
}
return bean;
}
}启动后的结果：
2018-09-08 16:25:55.238 INFO 2584 --- [ main] com.gyc.bean.LifeCycleProcessor : bean初始化之前执行：annotationBean
2018-09-08 16:25:55.238 INFO 2584 --- [ main] com.gyc.bean.AnnotationBean : AnnotationBean-init
2018-09-08 16:25:55.238 INFO 2584 --- [ main] com.gyc.bean.LifeCycleProcessor : bean初始化之后执行：annotationBean
2018-09-08 16:25:55.241 INFO 2584 --- [ main] com.gyc.bean.LifeCycleBean : LifeCycleBean-afterPropertiesSet
2018-09-08 16:25:55.246 INFO 2584 --- [ main] com.gyc.bean.LifeCycleBeanAware : bean的默认的名字：lifeCycleBeanAware
2018-09-08 16:25:55.246 INFO 2584 --- [ main] com.gyc.bean.LifeCycleBeanAware : bean工厂
2018-09-08 16:25:55.246 INFO 2584 --- [ main] com.gyc.bean.LifeCycleBeanAware : bean上下文
2018-09-08 16:25:55.279 INFO 2584 --- [ main] com.gyc.bean.CustomBean : CustomBean-init
2018-09-08 16:25:55.506 INFO 2584 --- [ main] o.s.j.e.a.AnnotationMBeanExporter : Registering beans for JMX exposure on startup
2018-09-08 16:25:55.539 INFO 2584 --- [ main] com.gyc.GycApplication : Started GycApplication in 1.922 seconds (JVM running for 3.01)
2018-09-08 16:25:55.544 INFO 2584 --- [ Thread-6] s.c.a.AnnotationConfigApplicationContext : Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@7b227d8d: startup date [Sat Sep 08 16:25:54 CST 2018]; root of context hierarchy
2018-09-08 16:25:55.548 INFO 2584 --- [ Thread-6] o.s.j.e.a.AnnotationMBeanExporter : Unregistering JMX-exposed beans on shutdown
2018-09-08 16:25:55.549 INFO 2584 --- [ Thread-6] com.gyc.bean.CustomBean : CustomBean-destroy
2018-09-08 16:25:55.549 INFO 2584 --- [ Thread-6] com.gyc.bean.LifeCycleBean : LifeCycleBean-destroy
2018-09-08 16:25:55.549 INFO 2584 --- [ Thread-6] com.gyc.bean.AnnotationBean : AnnotationBean-destroy梳理了bean的生命周期，大概明白了spring对bean的一个处理流程；
对最上边的图进行详细描述：
标签：nal ebean efault proc 引用 3.0 factor cap 接口
原文地址：https://www.cnblogs.com/guoyuchuan/p/9610501.html
