Spring在配置文件中的属性注入applicationContext.xml：
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns="http://www.springframework.org/schema/beans"
xmlns:p="http://www.springframework.org/schema/p"
xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd ">
<!-- 1.set方式注入:property标签引入属性和值 -->
<bean name="user1" class="cn.example.bean.User" >
<!--值类型注入: 为User对象中名为name的属性注入tom作为值 -->
<property name="name" value="tom" ></property>
<property name="age" value="18" ></property>
<!-- 引用类型注入: 为car属性注入下方配置的car对象 -->
<property name="car" ref="car" ></property>
</bean>
<!-- ============================================================ -->
<bean name="car" class="cn.example.bean.Car" >
<property name="name" value="天才" ></property>
<property name="color" value="黄色" ></property>
</bean>
<!-- ============================================================ -->
<!-- 2.构造函数注入：constructor-arg标签 -->
<bean name="user2" class="cn.example.bean.User" >
<!-- name: 构造函数的参数名 index:参数索引 type:参数类型-->
<constructor-arg name="name" index="0" type="java.lang.Integer" value="999" ></constructor-arg>
<constructor-arg name="car" ref="car" index="1" ></constructor-arg>
</bean>
<!-- ============================================================= -->
<!--3. p名称空间注入, 实际执行的是set方法
需要导入P名称空间 xmlns:p="http://www.springframework.org/schema/p"
值类型: p:属性名="值"；对象类型: p:属性名-ref="bean名称"-->
<bean name="user3" class="cn.example.bean.User" p:name="jack" p:age="20" p:car-ref="car"></bean>
<!-- ============================================================= -->
<!--4.spel注入:spring Expression Language sping表达式语言-->
<bean name="user4" class="cn.example.bean.User" >
<property name="name" value="#{user1.name}" ></property>
<property name="age" value="#{user3.age}" ></property>
<property name="car" ref="car" ></property>
</bean>
<!-- ============================================================= -->
<!--5. 复杂类型注入 -->
<bean name="cb" class="cn.example.c_injection.CollectionBean" >
<!-- 如果数组中只准备注入一个值(对象),直接使用value|ref即可
<property name="arr" value="tom" ></property> -->
<!-- array注入,多个元素注入 -->
<property name="arr">
<array>
<value>tom</value>
<value>jerry</value>
<ref bean="user4" />
</array>
</property>
<!-- 如果List中只准备注入一个值(对象),直接使用value|ref即可 -->
<!-- <property name="list" value="jack" ></property> -->
<property name="list" >
<list>
<value>jack</value>
<value>rose</value>
<ref bean="user3" />
</list>
</property>
<!-- map类型注入 -->
<property name="map" >
<map>
<entry key="url" value="jdbc:mysql:///crm" ></entry>
<entry key="user" value-ref="user4" ></entry>
<entry key-ref="user3" value-ref="user2" ></entry>
</map>
</property>
<!-- prperties 类型注入 -->
<property name="prop" >
<props>
<prop key="driverClass">com.jdbc.mysql.Driver</prop>
<prop key="userName">root</prop>
<prop key="password">1234</prop>
</props>
</property>
</bean>
</beans>
测试代码：
public void fun1(){
ApplicationContext ac = new ClassPathXmlApplicationContext("cn/itcast/c_injection/applicationContext.xml");
User u = (User) ac.getBean("user1");
//User u = (User) ac.getBean("user2");
//User u = (User) ac.getBean("user3");
//User u = (User) ac.getBean("user4");
//CollectionBean cb = (CollectionBean) ac.getBean("cb");
System.out.println(u);
}