第二节:依赖注入
IOC(控制反转:InverseofControl ) ,又称作 依赖注入,是一种重要的面向对象编程的法则来削减计算机程序 的耦合问题,也是轻量级的 Spring 框架的核心。
1,属性注入;
2,构造函数注入;(通过类型;通过索引;联合使用)
3,工厂方法注入;(非静态工厂,静态工厂)
4,泛型依赖注入;(Spring4 整合 Hibernate4 的时候顺带讲)
<?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="people" class="com.fx.entity.People"></bean> <!-- 属性注入 --> <bean id="people2" class="com.fx.entity.People"> <property name="id" value="1"></property> <property name="name" value="张三"></property> <property name="age" value="11"></property> </bean> <!-- 构造方法注入 --> <bean id="people3" class="com.fx.entity.People"> <constructor-arg type="int" value="2"></constructor-arg> <constructor-arg type="String" value="李四"></constructor-arg> <constructor-arg type="int" value="22"></constructor-arg> </bean> <bean id="people4" class="com.fx.entity.People"> <constructor-arg index="0" value="3"></constructor-arg> <constructor-arg index="1" value="王五"></constructor-arg> <constructor-arg index="2" value="55"></constructor-arg> </bean> <bean id="people5" class="com.fx.entity.People"> <constructor-arg index="0" type="int" value="4"></constructor-arg> <constructor-arg index="1" type="String" value="招六"></constructor-arg> <constructor-arg index="2" type="int" value="66"></constructor-arg> </bean> <bean id="peopleFactory" class="com.fx.factory.PeopleFactory"></bean> <!-- 工厂方法注入 --> <bean id="people7" factory-bean="peopleFactory" factory-method="createPeople"></bean> <bean id="people8" class="com.fx.factory.PeopleFactory2" factory-method="createPeople"></bean> </beans>