Spring之InitializingBean接口和DisposableBean接口的使用
作者：波波烤鸭
这篇文章主要介绍了Spring之InitializingBean接口和DisposableBean接口的使用方式,具有很好的参考价值,希望对大家有所帮助,如有错误或未考虑完全的地方,望不吝赐教
1.InitializingBean
该接口的作用是：
允许一个bean在它的所有必须属性被BeanFactory设置后，来执行初始化的工作，该接口中只有一个方法，afterPropertiesSet
public interface InitializingBean {
/**
* Invoked by the containing {@code BeanFactory} after it has set all bean properties
* and satisfied {@link BeanFactoryAware}, {@code ApplicationContextAware} etc.
* <p>This method allows the bean instance to perform validation of its overall
* configuration and final initialization when all bean properties have been set.
* @throws Exception in the event of misconfiguration (such as failure to set an
* essential property) or if initialization fails for any other reason
*/
void afterPropertiesSet() throws Exception;
}
2.DisposableBean
该接口的作用是：允许在容器销毁该bean的时候获得一次回调。
DisposableBean接口也只规定了一个方法：destroy
public interface DisposableBean {
/**
* Invoked by the containing {@code BeanFactory} on destruction of a bean.
* @throws Exception in case of shutdown errors. Exceptions will get logged
* but not rethrown to allow other beans to release their resources as well.
*/
void destroy() throws Exception;
}
3.案例演示
/**
* 实现InitializingBean和DisposableBean接口
* @author dengp
*
*/
public class User implements InitializingBean,DisposableBean{
private int id;
private String name;
private String beanName;
public User(){
System.out.println("User 被实例化");
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
System.out.println("设置："+name);
this.name = name;
}
public String getBeanName() {
return beanName;
}
public void setBeanName(String beanName) {
this.beanName = beanName;
}
@Override
public String toString() {
return "User [id=" + id + ", name=" + name + ", beanName=" + beanName + "]";
}
@Override
public void destroy() throws Exception {
// TODO Auto-generated method stub
System.out.println("destory ....");
}
@Override
public void afterPropertiesSet() throws Exception {
System.out.println("afterPropertiesSet....");
}
}
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" xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd"> <bean class="com.dpb.pojo.User" id="user" > <property name="name" value="波波烤鸭"></property> </bean> </beans>
测试代码
@Test
public void test1() {
ClassPathXmlApplicationContext ac = new ClassPathXmlApplicationContext("applicationContext.xml");
User user = ac.getBean(User.class);
System.out.println(user);
ac.registerShutdownHook();
}
输出结果：
User 被实例化
设置：波波烤鸭
afterPropertiesSet....
User [id=0, name=波波烤鸭, beanName=null]
destory ....
通过输出能够显示spring初始化bean的时候，如果bean实现了InitializingBean接口，会自动调用afterPropertiesSet方法，在bean被销毁的时候如果实现了DisposableBean接口会自动回调destroy方法后然后再销毁
总结
以上为个人经验，希望能给大家一个参考，也希望大家多多支持脚本之家。