原文鏈接：http://www.orlion.ga/189/

一、scope

bean的scope屬性中常用的有兩種：singleton（單例，默認）和prototype(原型，每次創(chuàng)建新對象)

例:beans.xml

<bean?id="userService"?class="ml.orlion.service.UserService"?scope="prototype"><property?name="userDao"?ref="userDao"/> </bean>

在java文件中:

BeanFactory?appContext?=?new?ClassPathXmlApplicationContext("beans.xml"); UserService?userService?=?(UserService)appContext.getBean("userService"); UserService?userServic2?=?(UserService)appContext.getBean("userService"); System.out.println(userService?==?userServic2);//?輸出false

二、集合注入

UserDAOImpl.java:

package?ml.orlion.dao.impl;import?java.util.List; import?java.util.Map; import?java.util.Set; import?ml.orlion.dao.UserDAO; import?ml.orlion.model.User;public?class?UserDAOImpl?implements?UserDAO{private?Set<String>?sets;private?List<String>?lists;private?Map<String?,?String>?maps;public?void?saveUser(User?user){System.out.println("save?usering");}public?Set<String>?getSets()?{return?sets;}public?void?setSets(Set<String>?sets)?{this.sets?=?sets;}public?List<String>?getLists()?{return?lists;}public?void?setLists(List<String>?lists)?{this.lists?=?lists;}public?Map<String,?String>?getMaps()?{return?maps;}public?void?setMaps(Map<String,?String>?maps)?{this.maps?=?maps;}public?String?toString(){return?sets.size()?+"|"+?lists.size()?+"|"+?maps.size();} }

beans.xml中配置:

<bean?id="userDao"?class="ml.orlion.dao.impl.UserDAOImpl"><property?name="sets"><set><value>1</value></set></property><property?name="lists"><list><value>1</value><value>2</value></list></property><property?name="maps"><map><entry?key="1"?value="1"></entry><entry?key="2"?value="2"></entry><entry?key="3"?value="3"></entry></map></property></bean>

然后測試一下:

BeanFactory?appContext?=?new?ClassPathXmlApplicationContext("beans.xml"); UserDAO?userDao?=?(UserDAO)?appContext.getBean("userDao"); System.out.println(userDao);//?輸出?1|2|3

三、自動裝配AutoWire

autowire屬性有六種值:autodatact、byName、byType、constructor、default、no

byName:按照名字自動去匹配

byType:按照類型自動匹配

?

UserDAOImpl.java:

package?ml.orlion.dao.impl;import?ml.orlion.dao.UserDAO; import?ml.orlion.model.User;public?class?UserDAOImpl?implements?UserDAO{//?添加id以區(qū)分private?int?daoId;public?int?getDaoId()?{return?daoId;}public?void?setDaoId(int?daoId)?{this.daoId?=?daoId;}public?void?saveUser(User?user){System.out.println("save?usering");}public?String?toString(){return?"daoId"?+?daoId;} }

beans.xml:

<bean?id="userDao"?class="ml.orlion.dao.impl.UserDAOImpl"><property?name="daoId"?value="1"></property></bean><bean?id="userDao2"?class="ml.orlion.dao.impl.UserDAOImpl"><property?name="daoId"?value="2"></property></bean><bean?id="userService"?class="ml.orlion.service.UserService"?scope="prototype"?autowire="byName"></bean>

測試一下：

BeanFactory?appContext?=?new?ClassPathXmlApplicationContext("beans.xml"); UserService?userService?=?(UserService)?appContext.getBean("userService"); System.out.println(userService.getUserDao());

這時候會輸出daoId=1

?

注:如果所有的bean都用同一種，可以使用beans的屬性:defalut-autowire

?

四、生命周期

1、lazy-init

????lazy-init="true"則bean在Ioc容器初始化的時候不進行初始化

注:可以beans標簽上設置default-lazy-init="true"

?

2、init-method(bean初始化的時候執(zhí)行)、destroy-method(bean銷毀的時候執(zhí)行)

UserService.java

package?ml.orlion.service;import?ml.orlion.dao.UserDAO; import?ml.orlion.dao.impl.UserDAOImpl; import?ml.orlion.model.User;public?class?UserService?{private?UserDAO?userDAO?=?new?UserDAOImpl();public?void?init(){System.out.println("init");}public?void?destroy(){System.out.println("destroy");}public?UserDAO?getUserDao()?{return?userDAO;}public?void?setUserDao(UserDAO?userDAO)?{this.userDAO?=?userDAO;}public?void?saveUser(User?user){this.userDAO.saveUser(user);} }

beans.xml:

<bean?id="userDao"?class="ml.orlion.dao.impl.UserDAOImpl"><property?name="daoId"?value="1"/></bean><bean?id="userService"?class="ml.orlion.service.UserService"?destroy-method="destroy"?init-method="init"><property?name="userDao"?ref="userDao"/></bean>

測試：

ClassPathXmlApplicationContext?appContext?=?new?ClassPathXmlApplicationContext("beans.xml"); UserService?userService?=?(UserService)?appContext.getBean("userService"); appContext.destroy();//?需要主動調用該方法才會銷毀bean

注:scope="prototype"時，調用destroy不會銷毀bean。Ioc容器不會管理bean的生命周期

轉載于:https://www.cnblogs.com/orlion/p/5350854.html

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