框架反转

本是古典何须时尚 2023-06-20 10:52 3阅读 0赞

## 框架反转 ##

框架简单反转

package dao;
    public interface UserDao {
        
        public void getUser();
    }
    
    package dao;
    public class UserDaoImpl implements UserDao {
        
        @Override
        public void getUser() {
        
            System.out.println("获取用户数据");
        }
    }
    
    package dao;
    public class UserDaoMysqlImpl implements UserDao {
        
    
       // private UserDao userDao=new UserDaoImpl()
        @Override
        public void getUser() {
        
            System.out.println("mqsql获取用户数据");
        }
    }
    
    package dao;
    public class UserDaoOrecleImpl implements UserDao {
        
        @Override
        public void getUser() {
        
            System.out.println("Orecle获取用户数据");
        }
    }
    
    
    package service;
    public interface UserService {
        
       public void getUser();
    }
    
    package service;
    import dao.UserDao;
    import dao.UserDaoImpl;
    import dao.UserDaoMysqlImpl;
    import dao.UserDaoOrecleImpl;
    public class UserServiceImpl implements UserService{
        
        private UserDao userDao;
        //利用set实现接口，不用创建那么多类
        public void setUserDao(UserDao userDao){
        
            this.userDao=userDao;
        }
        @Override
        public void getUser() {
        
           userDao.getUser();
        }
    }
    
    import dao.UserDaoImpl;
    import dao.UserDaoMysqlImpl;
    import dao.UserDaoOrecleImpl;
    import org.junit.Test;
    import service.UserService;
    import service.UserServiceImpl;
    public class UserTest {
        
        @Test
        public void test(){
        
            UserServiceImpl service=new UserServiceImpl();
            service.setUserDao(new UserDaoMysqlImpl());
            service.getUser();
            service.setUserDao(new UserDaoOrecleImpl());
            service.getUser();
            service.setUserDao(new UserDaoImpl());
            service.getUser();
        }
    }