Spring的几种初始化和销毁方法

一 指定初始化和销毁方法

通过@Bean指定init-method和destroy-method；

 @Bean(initMethod="init",destroyMethod="detory")
     public Car car(){
         return new Car();
     }

二 通过让Bean实现InitializingBean（定义初始化逻辑）

 @Component
 public class Cat implements InitializingBean,DisposableBean {

     public Cat(){
         System.out.println("cat constructor...");
     }
 ​
     @Override
     public void destroy() throws Exception {
         // TODO Auto-generated method stub
         System.out.println("cat...destroy...");
     }
 ​
     @Override
     public void afterPropertiesSet() throws Exception {
         // TODO Auto-generated method stub
         System.out.println("cat...afterPropertiesSet...");
     }
 ​
 }

三 可以使用JSR250

 @PostConstruct：在bean创建完成并且属性赋值完成；来执行初始化方法

 @PreDestroy：在容器销毁bean之前通知我们进行清理工作

 @Component
 public class Dog implements ApplicationContextAware {

     //@Autowired
     private ApplicationContext applicationContext;

     public Dog(){
         System.out.println("dog constructor...");
     }

     //对象创建并赋值之后调用
     @PostConstruct
     public void init(){
         System.out.println("Dog....@PostConstruct...");
     }

     //容器移除对象之前
     @PreDestroy
     public void detory(){
         System.out.println("Dog....@PreDestroy...");
     }
 ​
     @Override
     public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
         // TODO Auto-generated method stub
         this.applicationContext = applicationContext;
     }
 ​
 }

四 可以使用BeanPostProcessor

 /**
  * 后置处理器：初始化前后进行处理工作
  * 将后置处理器加入到容器中
  * 在bean初始化前后进行一些处理工作；
  * postProcessBeforeInitialization:在初始化之前工作
  * postProcessAfterInitialization:在初始化之后工作
  */
 @Component
 public class MyBeanPostProcessor implements BeanPostProcessor,Ordered {
 ​
     @Override
     public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
         // TODO Auto-generated method stub
         System.out.println("postProcessBeforeInitialization..."+beanName+"=>"+bean);
         return bean;
     }
 ​
     @Override
     public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
         // TODO Auto-generated method stub
         System.out.println("postProcessAfterInitialization..."+beanName+"=>"+bean);
         return bean;
     }
 ​
     @Override
     public int getOrder() {
         return 2;
     }
 ​
 }