在Bean的生命周期中，自定义初始化和销毁方法，除了使用@Bean注解的initMethod和destroyMethod属性之外，Spring还提供了两个接口方法，分别是InitializingBean和DisposableBean。
InitializingBean
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;
}
InitializingBean的作用时机在于，对象创建并将所有的属性设置完成后，进行初始化，其初始化方法就是afterPropertiesSet方法。
DisposableBean
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;
}
DisposableBean 的作用时机就是当容器关闭的时候，调用destroy方法执行销毁。
自定义Bean，实现InitializingBean和DisposableBean
@Component
public class Teacher implements InitializingBean, DisposableBean {
public Teacher() {
System.out.println("Teacher 构造器");
}
@Override
public void destroy() throws Exception {
System.out.println("Teacher 销毁");
}
@Override
public void afterPropertiesSet() throws Exception {
System.out.println("Teacher 初始化");
}
}
@Configuration
@ComponentScan("com.caiyq.spring.annotation.bean")
public class MainConfig {
}
测试
@Test
public void testBean() {
AnnotationConfigApplicationContext applicationContext =
new AnnotationConfigApplicationContext(MainConfig.class);
System.out.println("容器创建完成");
//关闭容器
applicationContext.close();
}
Teacher 构造器
Teacher 初始化
容器创建完成
Teacher 销毁
在afterPropertiesSet和destroy方法中，可实现具体的业务逻辑。
