IOC操作Bean管理（xml自动装配）

package com.atguigu.spring.autowire;public class Dept {@Overridepublic String toString() {return "Dept{}";}
}

package com.atguigu.spring.autowire;public class Emp {private Dept dept;public void setDept(Dept dept){this.dept = dept;}@Overridepublic String toString() {return "Emp{" +"dept=" + dept +'}';}public void test(){System.out.println(dept);}
}

传统方法:

<?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 = "emp" class = "com.atguigu.spring.autowire.Emp"><property name="dept" ref="dept"></property></bean><bean id = "dept" class = "com.atguigu.spring.autowire.Dept"></bean></beans>

1.什么是自动装配

（1）根据指定装配规则（属性名称或者属性类型），Spring自动将匹配的属性值进行注入

2.演示自动装配过程

（1）根据属性名称自动注入，注入值bean的id值和类属性名称一样

<?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"><!--实现自动装配bean标签属性autowire,配置自动装配autowire属性常用两个值：byName根据属性名称注入，byType根据属性类型注入--><bean id = "emp" class = "com.atguigu.spring.autowire.Emp" autowire="byName"></bean><bean id = "dept" class = "com.atguigu.spring.autowire.Dept"></bean></beans>

（2）根据属性类型自动注入

注意：相同类型不能有多个，不然它不知道注入哪一个

<?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"><!--实现自动装配bean标签属性autowire,配置自动装配autowire属性常用两个值：byName根据属性名称注入，byType根据属性类型注入--><bean id = "emp" class = "com.atguigu.spring.autowire.Emp" autowire="byType"></bean><bean id = "dept" class = "com.atguigu.spring.autowire.Dept"></bean></beans>