Spring注解驱动开发--生命周期

一、@Bean指定初始化和销毁方法

• 在@Bean注解里指定init-method和destory-method

      @Bean(initMethod = "init", destroyMethod = "destory")
  

二、InitializingBean和DisposableBean

• 让Bean实现InitializingBean（定义初始化逻辑）和DisposableBean（定义销毁逻辑）接口

  package org.hao.bean;
  
  import org.springframework.beans.factory.DisposableBean;
  import org.springframework.beans.factory.InitializingBean;
  import org.springframework.stereotype.Component;
  
  @Component
  public class Cat implements InitializingBean, DisposableBean {
        
        
      public Cat() {
        
        
          System.out.println("cat...constructor");
      }
  
      public void destroy() throws Exception {
        
        
          System.out.println("cat destory...");
      }
  
      public void afterPropertiesSet() throws Exception {
        
        
          System.out.println("cat afterPropertiesSet...");
      }
  }
  

三、@PostConstruct和@PreDestroy

• @PostConstruct：在Bean创建完成并且属性赋值完成之后来执行初始化方法
• @PreDestroy：在容器销毁Bean之前通知我们进行清理工作

  package org.hao.bean;
  
  import org.springframework.stereotype.Component;
  
  import javax.annotation.PostConstruct;
  import javax.annotation.PreDestroy;
  
  @Component
  public class Dog {
        
        
      public Dog() {
        
        
          System.out.println("dog constructor...");
      }
  
      //对象创建并赋值后调用
      @PostConstruct
      public void init(){
        
        
          System.out.println("Dog...PostConstruct");
      }
  
      //容器移除对象之前调用
      @PreDestroy
      public void destroy(){
        
        
          System.out.println("Dog...PreDestory");
      }
  }
  

四、BeanPostProcessor后置处理器

• 在Bean初始化前后进行处理

  package org.hao.bean;
  
  import org.springframework.beans.BeansException;
  import org.springframework.beans.factory.config.BeanPostProcessor;
  import org.springframework.stereotype.Component;
  
  @Component
  public class MyBeanPostProcessor implements BeanPostProcessor {
        
        
      public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {
        
        
          System.out.println("postProcessAfterInitialization" + beanName + "=>" + bean);
          return bean;
      }
  
      public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {
        
        
          System.out.println("postProcessBeforeInitialization" + beanName + "=>" + bean);
          return bean;
      }
  }