人体蜈蚣1 2 3百度云:Spring内核研究-管理bean的声明周期一（InitializingBean和init-method）

Spring内核研究-管理bean的声明周期一（InitializingBean和init-method）

InitializingBean

package research.spring.beanfactory.ch4;import org.springframework.beans.factory.InitializingBean;public class LifeCycleBean implements InitializingBean{public void afterPropertiesSet() throws Exception {System.out.println("LifeCycleBean initializing...");}}

xml version="1.0" encoding="UTF-8"?>DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN""http://www.springframework.org/dtd/spring-beans.dtd">bean>beans>

package research.spring.beanfactory.ch4;import org.springframework.beans.factory.xml.XmlBeanFactory;import org.springframework.core.io.ClassPathResource;public class LifeCycleTest {public static void main(String[] args) {XmlBeanFactory factory=new XmlBeanFactory(new ClassPathResource(
"research/spring/beanfactory/ch4/context.xml"));factory.getBean("lifeBean");}}

 SHAPE  \* MERGEFORMAT

装配bean的合作者

查看bean是否实现InitializingBean接口

调用afterPropertiesSet方法

init-method

package research.spring.beanfactory.ch4;public class LifeCycleBean{public void init(){System.out.println("LifeCycleBean.init...");}}

xml version="1.0" encoding="UTF-8"?>DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN//EN""http://www.springframework.org/dtd/spring-beans.dtd"> init-method="init">bean>beans>

       final protected void init() throws Exception{

           System.out.println("init method...");

           if(true) throw new Exception("init exception");

//……//在一个bean的合作者设备完成后，执行一个bean的初始化方法。protected void invokeInitMethods(String beanName, Object bean, RootBeanDefinition mergedBeanDefinition)
 throws Throwable {//判断bean是否实现了InitializingBean接口if (bean instanceof InitializingBean) {if (logger.isDebugEnabled()) {logger.debug("Invoking afterPropertiesSet() on bean with name ‘" + beanName + "‘");}//调用afterPropertiesSet方法((InitializingBean) bean).afterPropertiesSet();}//判断bean是否定义了init-methodif(mergedBeanDefinition!=null&&mergedBeanDefinition.getInitMethodName() != null) {//调用invokeCustomInitMethod方法来执行init-method定义的方法invokeCustomInitMethod(beanName, bean, mergedBeanDefinition.getInitMethodName());}}//执行一个bean定义的init-method方法protected void invokeCustomInitMethod(String beanName, Object bean, String initMethodName)throws Throwable {if (logger.isDebugEnabled()) {logger.debug("Invoking custom init method ‘" + initMethodName +"‘ on bean with name ‘" + beanName + "‘");}//使用方法名，反射Method对象Method initMethod = BeanUtils.findMethod(bean.getClass(), initMethodName, null);if (initMethod == null) {throw new NoSuchMethodException(
"Couldn‘t find an init method named ‘" + initMethodName + "‘ on bean with name ‘" + beanName + "‘");}//判断方法是否是publicif (!Modifier.isPublic(initMethod.getModifiers())) {//设置accessible为true，可以访问private方法。                     initMethod.setAccessible(true);}try {//反射执行这个方法initMethod.invoke(bean, (Object[]) null);}catch (InvocationTargetException ex) {throw ex.getTargetException();}}//………..