@Qualifier 注解和 @Autowired 注解一起使用可以指定装配的Bean是哪一个来消除混乱
    使用@Qualifier 注解时，要在配置文件中添加以下代码

    1. 在 beans 中添加 xmlns:context 属性
    2. xmlns:context="http://www.springframework.org/schema/context"
    3. 在 beans 的 xsi:schemaLocation 属性中添加并用空格分隔
    4. http://www.springframework.org/schema/context
    5. http://www.springframework.org/schema/context/spring-context-3.0.xsd
    6. beans 内添加
    7. <context:annotation-config/>

    案例代码：
    Person.java

    1. package com.baklib.custom;
    3. public class Person {
    5.     private String name;
    6.     private Integer age;
    8.     public Integer getAge() {
    9.         return age;
    10.     }
    12.     public void setAge(Integer age) {
    13.         this.age = age;
    14.     }
    16.     public String getName() {
    17.         return name;
    18.     }
    20.     public void setName(String name) {
    21.         this.name = name;
    22.     }
    23. }

    Action.java

    1. package com.baklib.custom;
    3. import org.springframework.beans.factory.annotation.Autowired;
    4. import org.springframework.beans.factory.annotation.Qualifier;
    6. public class Action {
    8.     @Autowired
    9.     @Qualifier("person1")
    10.     private Person person;
    12.     public void sayHello() {
    13.         System.out.println("Hello, "+person.getName()+" is " + person.getAge());
    14.     }
    16. }

    MainApp.java

    1. package com.baklib.custom;
    3. import org.springframework.context.ApplicationContext;
    4. import org.springframework.context.support.ClassPathXmlApplicationContext;
    6. public class MainApp {
    8.     public static void main(String[] args) {
    9.         ApplicationContext context = new ClassPathXmlApplicationContext("Beans.xml");
    11.         Action action = (Action) context.getBean("action");
    12.         action.sayHello();
    13.     }
    15. }

    配置文件 Beans.xml

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <beans xmlns="http://www.springframework.org/schema/beans"
    3.        xmlns:context="http://www.springframework.org/schema/context"
    4.        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    5.        xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.0.xsd">
    7.     <context:annotation-config/>
    9.     <bean id="action" class="com.baklib.custom.Action"></bean>
    11.     <bean id="person1" class="com.baklib.custom.Person">
    12.         <property name="name" value="张三" />
    13.         <property name="age" value="22" />
    14.     </bean>
    16.     <bean id="person" class="com.baklib.custom.Person">
    17.         <property name="name" value="李四" />
    18.         <property name="age" value="20" />
    19.     </bean>
    21. </beans>

    编写完以上代码，就可以运行这个程序，运行结束后，可以在控制台看到下面的信息

    1. Hello, 张三 is 22