编写第一个spring程序

浅浅的花香味﹌ 2022-12-31 13:19 250阅读 0赞

## 1.创建一个maven工程，在DAO层创建接口和对应的实现类 ##

package com.zhu.dao;
    
    public interface UserDao {
        
    
        void getUser();
    }

package com.zhu.dao;
    
    public class UserDaoImpl implements UserDao{
        
    
        @Override
        public void getUser() {
        
            System.out.println("默认获取用户的数据");
        }
    }

package com.zhu.dao;
    
    public class UserDaoImpl2 implements  UserDao{
        
        @Override
        public void getUser() {
        
            System.out.println("默认获取用户的数据2");
        }
    }

package com.zhu.dao;
    
    public class UserDaoImpl3 implements  UserDao{
        
        @Override
        public void getUser() {
        
            System.out.println("默认获取用户的数据3");
        }
    }

package com.zhu.dao;
    
    public class UserDaoImpl4 implements  UserDao{
        
        @Override
        public void getUser() {
        
            System.out.println("默认获取用户的数据4");
        }
    }

## 2.在pom.xml文件中导入依赖包 ##

<dependencies>
            <dependency>
                <groupId>org.springframework</groupId>
                <artifactId>spring-webmvc</artifactId>
                <version>5.2.0.RELEASE</version>
            </dependency>
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>4.12</version>
                <scope>test</scope>
            </dependency>
        </dependencies>

## 3.在Service层创建接口和实现类 ##

package com.zhu.service;
    
    public interface UserService {
        
        void getUser();
    }

package com.zhu.service;
    
    import com.zhu.dao.UserDao;
    import com.zhu.dao.UserDaoImpl;
    import com.zhu.dao.UserDaoImpl2;
    import com.zhu.dao.UserDaoImpl3;
    
    public class UserServiceImpl implements UserService{
        
    
        private UserDao userDao;
    
        public void setUserDao(UserDao userDao) {
        
            this.userDao = userDao;
        }
        @Override
        public void getUser() {
        
    userDao.getUser();
        }
    }

## 4.创建bean配置文件，并且将实现类配置在bean文件中 ##

<?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-3.0.xsd">
    
        <bean id="UserDaoImpl1" class="com.zhu.dao.UserDaoImpl"></bean>
        <bean id="UserDaoImpl2" class="com.zhu.dao.UserDaoImpl2"></bean>
        <bean id="UserDaoImpl3" class="com.zhu.dao.UserDaoImpl3"></bean>
        <bean id="UserDaoImpl4" class="com.zhu.dao.UserDaoImpl4"></bean>
    
        <bean id="UserServiceImpl" class="com.zhu.service.UserServiceImpl">
            <property name="userDao" ref="UserDaoImpl1"></property>
        </bean>
    </beans>

## 5.创建一个测试类执行程序 ##

import com.zhu.dao.UserDao;
    import com.zhu.dao.UserDaoImpl;
    import com.zhu.dao.UserDaoImpl2;
    import com.zhu.dao.UserDaoImpl4;
    import com.zhu.service.UserService;
    import com.zhu.service.UserServiceImpl;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.support.ClassPathXmlApplicationContext;
    
    public class MyTest {
        
    
        public static void main(String[] args){
        
    
    //        UserServiceImpl userService =new UserServiceImpl();
    //        userService.setUserDao(new UserDaoImpl());
    //        userService.getUser();
    
            ApplicationContext context = new ClassPathXmlApplicationContext("beans.xml");
            UserServiceImpl userService = (UserServiceImpl) context.getBean("UserServiceImpl");
            userService.getUser();
        }
    }