在Spring中，既可以实现InitializingBean和DisposableBean接口或在bean配置文件中指定 init-method 和 destroy-method 在初始化和销毁回调函数。在这篇文章中，我们将介绍如何使用 @PostConstruct 和 @PreDestroy 注解来做同样的事情。

@PostConstruct 和 @PreDestroy

package com.yiibai.customer.services;import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;public class CustomerService
{String message;public String getMessage() {return message;}public void setMessage(String message) {this.message = message;}@PostConstructpublic void initIt() throws Exception {System.out.println("Init method after properties are set : " + message);}@PreDestroypublic void cleanUp() throws Exception {System.out.println("Spring Container is destroy! Customer clean up");}}

1. CommonAnnotationBeanPostProcessor

<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans-2.5.xsd"><bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" /><bean id="customerService" class="com.yiibai.customer.services.CustomerService"><property name="message" value="i'm property message" /></bean></beans>

2. <context:annotation-config />

<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/beanshttp://www.springframework.org/schema/beans/spring-beans-2.5.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context-2.5.xsd"><context:annotation-config /><bean id="customerService" class="com.yiibai.customer.services.CustomerService"><property name="message" value="i'm property message" /></bean></beans>

执行结果

package com.yiibai.common;import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;import com.yiibai.customer.services.CustomerService;public class App
{public static void main( String[] args ){ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"Spring-Customer.xml"});CustomerService cust = (CustomerService)context.getBean("customerService");System.out.println(cust);context.close();}
}

输出结果

Init method after properties are set : im property message
com.yiibai.customer.services.CustomerService@47393f
...
INFO: Destroying singletons in org.springframework.beans.factory.
support.DefaultListableBeanFactory@77158a:
defining beans [customerService]; root of factory hierarchy
Spring Container is destroy! Customer clean up