上一博客主要学习了下bean的配置、注入、自定义属性编辑器,今天来熟悉bean的生命周期。在开发中生命周期是一个很常见的名词,基本每种编程语言都能找到与它关联的。关于bean的生命周期我在网上也找了好多,基本都差不多。这里我主要是想通过代码来验证,毕竟学的知识都是一样的,都是学的Java,最重要的是动手练习,这样印象更深。下面是它生命周期的描述,我们通过demo来进行验证。下图是它执行的顺序。
一、创建LiftCycle类实现BeanFactoryAware,BeanNameAware,InitializingBean,DisposableBean,ApplicationContextAware5个接口方法
package Cuiyw.Spring.Service; import org.springframework.beans.BeansException; import org.springframework.beans.factory.BeanFactory; import org.springframework.beans.factory.BeanFactoryAware; import org.springframework.beans.factory.BeanNameAware; import org.springframework.beans.factory.DisposableBean; import org.springframework.beans.factory.InitializingBean; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; public class LifeCycle implements BeanFactoryAware,BeanNameAware,InitializingBean,DisposableBean,ApplicationContextAware{ private String name; public String getName() { System.out.println("getName name="+name); return name; } public void setName(String name) { System.out.println("setName name="+name); this.name = name; } public void afterPropertiesSet() throws Exception { // TODO Auto-generated method stub System.out.println("InitializingBean.afterPropertiesSet()"); } public void setBeanName(String arg0) { // TODO Auto-generated method stub System.out.println("BeanNameAware.setBeanName"); } public void setBeanFactory(BeanFactory arg0) throws BeansException { // TODO Auto-generated method stub System.out.println("BeanFactoryAware.setBeanFactory"); } public void destroy() throws Exception { // TODO Auto-generated method stub System.out.println("DisposableBean.destroy"); } public void myInit() { System.out.println("【init-method】调用<bean>的init-method属性指定的初始化方法"); } public void myDestory() { System.out.println("【destroy-method】调用<bean>的destroy-method属性指定的初始化方法"); } public void setApplicationContext(ApplicationContext arg0) throws BeansException { // TODO Auto-generated method stub System.out.println("ApplicationContextAware.setApplicationContext"); } }
二、注册InstantiationAwareBeanPostProcessor接口
package Cuiyw.Spring.Service; import java.beans.PropertyDescriptor; import org.springframework.beans.BeansException; import org.springframework.beans.PropertyValues; import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessor; public class MyInstantiationAwareBeanPostProcessor implements InstantiationAwareBeanPostProcessor{ public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("InstantiationAwareBeanPostProcessor.postProcessAfterInitialization"); return bean; } public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("InstantiationAwareBeanPostProcessor.postProcessBeforeInitialization"); return bean; } public boolean postProcessAfterInstantiation(Object bean, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("InstantiationAwareBeanPostProcessor.postProcessAfterInstantiation"); return true; } public Object postProcessBeforeInstantiation(Class<?> beanClass, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("InstantiationAwareBeanPostProcessor.postProcessBeforeInstantiation"); return null; } public PropertyValues postProcessPropertyValues(PropertyValues pvs, PropertyDescriptor[] pds, Object bean, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("InstantiationAwareBeanPostProcessor.postProcessPropertyValues"); return pvs; } }
三、注册BeanPostProcessor接口
其实InstantiationAwareBeanPostProcessor继承BeanPostProcessor,所以在上面我也实现了BeanPostProcessor接口的方法
package Cuiyw.Spring.Service; import org.springframework.beans.BeansException; import org.springframework.beans.factory.config.BeanPostProcessor; public class MyBeanPostProcessor implements BeanPostProcessor { public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("BeanPostProcessor.postProcessAfterInitialization "); return bean; } public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException { // TODO Auto-generated method stub System.out.println("BeanPostProcessor.postProcessBeforeInitialization"); return bean; } }
四、注册BeanFactoryPostProcessor接口
package Cuiyw.Spring.Service; import org.springframework.beans.BeansException; import org.springframework.beans.factory.config.BeanFactoryPostProcessor; import org.springframework.beans.factory.config.ConfigurableListableBeanFactory; public class MyBeanFactoryPostProcessor implements BeanFactoryPostProcessor { public void postProcessBeanFactory(ConfigurableListableBeanFactory arg0) throws BeansException { // TODO Auto-generated method stub System.out.println("BeanFactoryPostProcessor.postProcessBeanFactory"); } }
五、在上下文中配置
这里还是在上一个博客demo的基础上进行修改,为了有其他干扰,我先把service去掉了。
<?xml version="1.0" encoding="UTF-8"?> <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.xsd"> <bean id="beanPostProcessor" class="Cuiyw.Spring.Service.MyBeanPostProcessor"></bean> <bean id="instantiationAwareBeanPostProcessor" class="Cuiyw.Spring.Service.MyInstantiationAwareBeanPostProcessor"></bean> <bean id="beanFactoryPostProcessor" class="Cuiyw.Spring.Service.MyBeanFactoryPostProcessor"></bean> <bean id="lifeCycle" class="Cuiyw.Spring.Service.LifeCycle" init-method="myInit" destroy-method="myDestory"> <property name="name" value="cuiyw1"></property> </bean> </beans>
六、在main中使用bean
package Cuiyw.SpringAop; import org.springframework.beans.factory.BeanFactory; import org.springframework.context.ApplicationContext; import org.springframework.context.support.ClassPathXmlApplicationContext; import Cuiyw.Spring.IService.IService; import Cuiyw.Spring.Service.LifeCycle; public class App { public static void main( String[] args ) { ApplicationContext context=new ClassPathXmlApplicationContext(new String[]{"ApplicationContext.xml"}); BeanFactory factory=context; LifeCycle lifeCycle=factory.getBean("lifeCycle",LifeCycle.class); lifeCycle.setName("cuiyw2"); System.out.println("lifeCycle.name="+lifeCycle.getName()); ((ClassPathXmlApplicationContext)factory).registerShutdownHook(); /*service=(IService)factory.getBean("ServiceA"); service.service("Cuiyw ServiceA"); service=(IService)factory.getBean("ServiceImpl"); service.service("Cuiyw ServiceImpl"); */ } }
七、输入打印结果
可以发现输出的顺序和上面图的顺序基本一致。