init-method 和 destroy-method
@PostConstruct 和 @PreDestroy
In Spring, InitializingBean and DisposableBean are two marker interfaces, a useful way for Spring to perform certain actions upon bean initialization and destruction.
- For bean implemented InitializingBean, it will run
afterPropertiesSet()after all bean properties have been set. - For bean implemented DisposableBean, it will run
destroy()after Spring container is released the bean.
In Spring, you can use init-method and destroy-method as attribute in bean configuration file for bean to perform certain actions upon initialization and destruction.
Note
The @PostConstruct and @PreDestroy annotation are not belong to Spring, it’s located in the J2ee library – common-annotations.jar.具体的使用
对于第一个：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 | import org.springframework.beans.factory.DisposableBean; import org.springframework.beans.factory.InitializingBean; public class CustomerService implements InitializingBean, DisposableBean { String message; public String getMessage() { return message; } public void setMessage(String message) { this .message = message; } public void afterPropertiesSet() throws Exception { System.out.println( "Init method after properties are set : " + message); } public void destroy() throws Exception { System.out.println( "Spring Container is destroy! Customer clean up" ); } } |
下面的例子展示了 init-method and destroy-method.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 | public class CustomerService { String message; public String getMessage() { return message; } public void setMessage(String message) { this .message = message; } public void initIt() throws Exception { System.out.println( "Init method after properties are set : " + message); } public void cleanUp() throws Exception { System.out.println( "Spring Container is destroy! Customer clean up" ); } } |
| 1 2 3 4 5 6 7 8 9 10 11 12 | < 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-2.5.xsd"> < bean id="customerService" class="com.mkyong.customer.services.CustomerService" init-method="initIt" destroy-method="cleanUp"> < property name="message" value="i'm property message" /> </ bean > </ beans > |
第三种的使用：
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 | 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; } @PostConstruct public void initIt() throws Exception { System.out.println( "Init method after properties are set : " + message); } @PreDestroy public void cleanUp() throws Exception { System.out.println( "Spring Container is destroy! Customer clean up" ); } } |
By default, Spring will not aware of the @PostConstruct and @PreDestroy annotation. To enable it, you have to either register ‘CommonAnnotationBeanPostProcessor‘ or specify the ‘<context:annotation-config />‘ in bean configuration file,
1. CommonAnnotationBeanPostProcessor
| 1 2 3 4 5 6 7 8 9 10 11 12 | < 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-2.5.xsd"> < bean class="org.springframework.context.annotation.CommonAnnotationBeanPostProcessor" /> < bean id="customerService" class="com.mkyong.customer.services.CustomerService"> < property name="message" value="i'm property message" /> </ bean > </ beans > |
2. <context:annotation-config />
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | < 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-2.5.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd"> < context:annotation-config /> < bean id="customerService" class="com.mkyong.customer.services.CustomerService"> < property name="message" value="i'm property message" /> </ bean > </ beans > |
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本文转自被遗忘的博客园博客，原文链接：http://www.cnblogs.com/rollenholt/archive/2012/12/27/2835289.html，如需转载请自行联系原作者