The life cycle of spring beans

First, Initialize and destroy

1, the project structure is as follows:

2. New Replyservice class

 package   hjp.spring.beanlifecycle;  public  class   Replyservice { void   Addreply () {System.out.println (" Add Replay ");  public  void   Myinit () {System.out.println ( "Init method" );  public  void   Mydestroy () {System.out.println ( "Destroy Method" ); }}

3. Create a new Beans.xml document, Init-method specify the execution method at initialization, Destroy-method specify the method to execute when the bean is destroyed

Note: The Destruction method requires: (1), must be a singleton (2), must close the container

<?XML version= "1.0" encoding= "UTF-8"?><Beansxmlns= "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/bean S/spring-beans.xsd ">    <BeanID= "Replyserviceid"class= "Hjp.spring.beanlifecycle.ReplyService"Init-method= "Myinit"Destroy-method= "Mydestroy"></Bean></Beans>

4. New Test class

 Packagehjp.spring.beanlifecycle;Importorg.junit.Test;ImportOrg.springframework.context.ApplicationContext;ImportOrg.springframework.context.support.ClassPathXmlApplicationContext; Public classTestApp {@Test Public voiddemo1 () {Classpathxmlapplicationcontext ApplicationContext=NewClasspathxmlapplicationcontext ("Hjp/spring/beanlifecycle/beans.xml"); Replyservice Replyservice= Applicationcontext.getbean ("Replyserviceid", Replyservice.class);        Replyservice.addreply ();    Applicationcontext.close (); }}

Second, post-processing beans

1. The spring post-processing bean provides a mechanism to modify the instance object

2. Post-processing bean usage

(1), write implementation class, implement Interface Beanpostprocessor

 Packagehjp.spring.beanlifecycle;Importorg.springframework.beans.BeansException;ImportOrg.springframework.beans.factory.config.BeanPostProcessor; Public classMybeanpostprocessorImplementsBeanpostprocessor {/*** The Postprocessafterinitialization initialization method (that is, the Myinit method in the example) executes the * Postprocessbeforeinitialization initialization method (that is, in the example Myin It method) after executing the * Bean refers to the instance object created by spring, which is equivalent to the attribute class instantiation object of the configuration node bean in beans * beanname refers to spring to create the instance name, which is the attribute ID of the configuration node bean in beans; Beanname The bean by filtering * If no action is made, the bean must be returned or the null pointer error*/@Override PublicObject Postprocessbeforeinitialization (Object bean, String beanname)throwsbeansexception {//TODO auto-generated Method StubSystem.out.println ("Pre-initialization"); returnBean; } @Override PublicObject Postprocessafterinitialization (Object bean, String beanname)throwsbeansexception {//TODO auto-generated Method StubSYSTEM.OUT.PRINTLN ("After initialization"); returnBean; }}

(2), the implementation class is configured to the Spring container, the spring container when the bean is created, is automatically used after processing the bean

<?XML version= "1.0" encoding= "UTF-8"?><Beansxmlns= "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/bean S/spring-beans.xsd ">    <!--To create a target class -    <BeanID= "Replyserviceid"class= "Hjp.spring.beanlifecycle.ReplyService"Init-method= "Myinit"Destroy-method= "Mydestroy"></Bean>    <!--Configure post-processing beans, just configure class,spring to automatically use -    <Beanclass= "Hjp.spring.beanlifecycle.MyBeanPostProcessor"></Bean></Beans>

The life cycle of spring beans