為什么80%的碼農(nóng)都做不了架構師？>>> ??

Bean生命周期和后置處理器
IOC容器的bean生命周期
1.構造器或工廠方法建立bean實例
2.bean屬性賦值，引用其他bean
3.bean實例傳遞給bean后置處理器的BeforeInitialzation()
4.調用bean初始化方法init-method()
5.bean實例傳遞給bean后置處理器的AfterInitialzation()
6.使用bean實例
7.關閉ioc容器，調用bean銷毀方法destory-method()

bean設置了init-method and destroy-method屬性

Bean后置處理器
implements BeanPostProcessor實現(xiàn)2個方法
postProcessBeforeInitialization()
postProcessAfterInitialization()
調用初始化方法前后對bean進行額外處理
對所有bean逐一處理
IOC自動識別后置處理器

<?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="car"?class="cycle.Car"?init-method="init"?destroy-method="destory"><property?name="brand"?value="audi"/></bean><!--?后置處理器，實現(xiàn)BeanPostProcessor接口的2個方法postProcessBeforeInitialization在init-method之前調用postProcessAfterInitialization在int-method之后調用返回實際的bean，可以修改不需要配置id，IOC容器自動識別--><bean?class="cycle.MyBean"></bean> </beans> package?cycle;import?org.springframework.beans.BeansException; import?org.springframework.beans.factory.config.BeanPostProcessor;/***?后置處理器，缺省處理所有的bean*/ public?class?MyBean?implements?BeanPostProcessor{@Overridepublic?Object?postProcessBeforeInitialization(Object?bean,?String?beanName)?throws?BeansException?{System.out.println("postProcessBeforeInitialization?:?"?+?beanName?);if?("car".equals(beanName))?{}return?bean;}@Overridepublic?Object?postProcessAfterInitialization(Object?o,?String?s)?throws?BeansException?{System.out.println("postProcessAfterInitialization?:?"?+?s?);Car?car?=?new?Car();car.setBrand("benz");return?car;} } package?cycle;public?class?Car?{private?String?brand;public?Car()?{System.out.println("this?is?car?constructor.");}public?void?setBrand(String?brand)?{System.out.println("setting?brand?...");this.brand?=?brand;}public?void?init()?{System.out.println("init?...");}public?void?destory()?{System.out.println("destory...");}@Overridepublic?String?toString()?{return?"Car{"?+"brand='"?+?brand?+?'\''?+'}';} } package?cycle;import?org.springframework.context.ApplicationContext; import?org.springframework.context.support.ClassPathXmlApplicationContext;public?class?Main?{public?static?void?main(String[]?args)?{ClassPathXmlApplicationContext?ctx?=?new?ClassPathXmlApplicationContext("cycle//cycle.xml");Car?car?=?(Car)?ctx.getBean("car");System.out.println(car);//close?IOC?containerctx.close();} }

轉載于:https://my.oschina.net/jimyao/blog/631716

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