Spring 注入外部bean

「爱情、让人受尽委屈。」 2022-12-17 10:56 130阅读 0赞

# ![20201023144833595.png][] #

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# 一、新建类 #

### 1.dao层 ###

UserDao.java

public interface UserDao {
        public void update();
    }

UserDaoImpl.java

public class UserDaoImpl implements UserDao{
        @Override
        public void update() {
            System.out.println("dao update............");
        }
    }

### 2.service层 ###

UserService.java

public class UserService {
        //创建UserDao类型属性,生成set方法
        private UserDao userDao;
    
        public void setUserDao(UserDao userDao) {
            this.userDao = userDao;
        }
    
        public void add(){
            System.out.println("service add.............");
            userDao.update();
        }
    }

# 二、编写配置文件 #

在配置文件中配置对象创建并进行注入

bean6.xml

<?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="userService" class="com.health.IOC.F_注入外部bean.service.UserService">
            
            <property name="userDao" ref="userDao"/>
        </bean>
        <bean id="userDao" class="com.health.IOC.F_注入外部bean.dao.UserDaoImpl"></bean>
    </beans>

# 三、测试 #

test6.java

public class test6 {
        public static void main(String[] args) {
            //1.加载spring配置文件
            ApplicationContext context =
                    new ClassPathXmlApplicationContext("com/health/IOC/F_注入外部bean/bean6.xml");
            //2.获取配置创建的对象
            UserService userService = context.getBean("userService", UserService.class);
            userService.add();
        }
    }

输出结果：

![20201023144802903.png][]

[20201023144833595.png]: /images/20221122/bfe7cc3d0aae4a458ac4f7a28f77451b.png
[20201023144802903.png]: /images/20221122/dacb6eb2895a481c95bd45911b966518.png