通过Spring @PostConstruct 和 @PreDestroy 方法实现初始化和销毁bean之前进行的操作

落日映苍穹つ 2021-09-11 05:16 345阅读 0赞

关于在[spring][]  容器初始化 bean 和销毁前所做的操作定义方式有三种：

[第一种：通过@PostConstruct 和 @PreDestroy 方法 实现初始化和销毁bean之前进行的操作][PostConstruct _ _PreDestroy _ _bean]

第二种是：[通过 在xml中定义init-method 和  destory-method方法][_xml_init-method _ _destory-method]

第三种是：[ 通过bean实现InitializingBean和 DisposableBean接口][bean_InitializingBean_ DisposableBean]

下面演示通过  @PostConstruct 和 @PreDestory

1:定义相关的实现类：

package com.myapp.core.annotation.init;  
      
    import javax.annotation.PostConstruct;  
    import javax.annotation.PreDestroy;  
      
    public class PersonService {  
        
        private String  message;  
      
        public String getMessage() {  
            return message;  
        }  
      
        public void setMessage(String message) {  
            this.message = message;  
        }  
          
        @PostConstruct  
        public void  init(){  
            System.out.println("I'm  init  method  using  @PostConstrut...."+message);  
        }  
          
        @PreDestroy  
        public void  dostory(){  
            System.out.println("I'm  destory method  using  @PreDestroy....."+message);  
        }  
          
    }

2：定义相关的配置文件：

<?xml version="1.0" encoding="UTF-8"?>  
    <beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
    http://www.springframework.org/schema/beans/spring-beans-3.1.xsd  
    http://www.springframework.org/schema/context  
    http://www.springframework.org/schema/context/spring-context-3.1.xsd">  
      
      
      
    <context:annotation-config />  
      
    <bean id="personService" class="com.myapp.core.annotation.init.PersonService">  
      <property name="message" value="123"></property>  
    </bean>  
      
    </beans>

其中<context:annotation-config />告诉spring 容器采用注解配置：扫描注解配置；

[测试][Link 1]类：

package com.myapp.core.annotation.init;  
      
    import org.springframework.context.ApplicationContext;  
    import org.springframework.context.support.ClassPathXmlApplicationContext;  
      
    public class MainTest {  
          
        public static void main(String[] args) {  
              
            ApplicationContext  context = new ClassPathXmlApplicationContext("resource/annotation.xml");  
              
            PersonService   personService  =  (PersonService)context.getBean("personService");  
              
            personService.dostory();  
        }  
      
    }

测试结果：

I'm  init  method  using  @PostConstrut....123  
I'm  destory method  using  @PreDestroy.....123

其中也可以通过申明加载org.springframework.context.annotation.CommonAnnotationBeanPostProcessor

类来告诉Spring容器采用的 常用 注解配置的方式：

只需要修改配置文件为：

<?xml version="1.0" encoding="UTF-8"?>  
    <beans xmlns="http://www.springframework.org/schema/beans"  
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
    xmlns:context="http://www.springframework.org/schema/context"  
    xsi:schemaLocation="http://www.springframework.org/schema/beans  
    http://www.springframework.org/schema/beans/spring-beans-3.1.xsd  
    http://www.springframework.org/schema/context  
    http://www.springframework.org/schema/context/spring-context-3.1.xsd">  
      
      
      
      
      
      
    <bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />  
    <bean id="personService" class="com.myapp.core.annotation.init.PersonService">  
              <property name="message" value="123"></property>  
    </bean>  
      
      
      
    </beans>

同样可以得到以上测试的输出结果。

[spring]: http://lib.csdn.net/base/javaee
[PostConstruct _ _PreDestroy _ _bean]: http://write.blog.csdn.net/postedit/8681497
[_xml_init-method _ _destory-method]: http://blog.csdn.net/topwqp/article/details/8681467
[bean_InitializingBean_ DisposableBean]: http://blog.csdn.net/topwqp/article/details/8681573
[Link 1]: http://lib.csdn.net/base/softwaretest