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 第二种是：通过 在xml中定义init-method 和 destory-method方法 第三种是： 通过bean实现InitializingBean和 DisposableBean接口
下面演示通过 @PostConstruct 和 @PreDestory
第一种：
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:component-scan base-package="com.myapp.core.jsr330"/> --> <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">
<!-- <context:component-scan base-package="com.myapp.core.jsr330"/> -->
<!-- <context:annotation-config /> -->
<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。
----------------------------------------------------------
第二种：
1：在xml中配置 init-method和 destory-method方法
只是定义spring 容器在初始化bean 和容器销毁之前的所做的操作基于xml的配置只是一种方式：
直接上xml中配置文件:
<bean id="personService" class="com.myapp.core.beanscope.PersonService" scope="singleton" init-method="init" destroy-method="cleanUp"> </bean>
定义PersonService类：
package com.myapp.core.beanscope;
public class PersonService {
private String message;
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
public void init(){
System.out.println("init");
}
// how validate the destory method is a question
public void cleanUp(){
System.out.println("cleanUp");
}
}
相应的测试类：
package com.myapp.core.beanscope;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainTest {
public static void main(String[] args) {
AbstractApplicationContext context =new ClassPathXmlApplicationContext("SpringBeans.xml");
PersonService person = (PersonService)context.getBean("personService");
person.setMessage("hello spring");
PersonService person_new = (PersonService)context.getBean("personService");
System.out.println(person.getMessage());
System.out.println(person_new.getMessage());
context.registerShutdownHook();
}
}
测试结果：
init hello spring hello spring cleanUp
可以看出 init 方法和 clean up方法都已经执行了。
context.registerShutdownHook(); 是一个钩子方法，当jvm关闭退出的时候会调用这个钩子方法，在设计模式之 模板模式中 通过在抽象类中定义这样的钩子方法由实现类进行实现，这里的实现类是AbstractApplicationContext，这是spring 容器优雅关闭的方法。
----------------------------------------------------------
第三种：
1：定义相应类实现InitializingBean ,DisposableBean 接口
package com.myapp.core.annotation.init;
import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.InitializingBean;
public class PersonService implements InitializingBean,DisposableBean{
private String message;
public String getMessage() {
return message;
}
public void setMessage(String message) {
this.message = message;
}
@Override
public void destroy() throws Exception {
// TODO Auto-generated method stub
System.out.println("I‘m init method using implements InitializingBean interface...."+message);
}
@Override
public void afterPropertiesSet() throws Exception {
// TODO Auto-generated method stub
System.out.println("I‘m init method using implements DisposableBean interface...."+message);
}
}
2：定义相应的配置文件:
<?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:component-scan base-package="com.myapp.core.jsr330"/> -->
<!-- <context:annotation-config /> -->
<!-- <bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" />
<bean id="personService" class="com.myapp.core.annotation.init.PersonService">
<property name="message" value="123"></property>
</bean>
-->
<bean id="personService" class="com.myapp.core.annotation.init.PersonService">
<property name="message" value="123"></property>
</bean>
</beans>
3：测试类：
package com.myapp.core.annotation.init;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class MainTest {
public static void main(String[] args) {
AbstractApplicationContext context = new ClassPathXmlApplicationContext("resource/annotation.xml");
PersonService personService = (PersonService)context.getBean("personService");
context.registerShutdownHook();
}
}
4：输出测试结果：
I‘m init method using implements DisposableBean interface....123 三月 16, 2013 5:06:34 下午 org.springframework.context.support.AbstractApplicationContext doClose INFO: Closing org[email protected]205756: startup date [Sat Mar 16 17:06:30 CST 2013]; root of context hierarchy I‘m init method using implements InitializingBean interface....123
时间： 2024-08-06 07:56:31