Go语言视频零基础入门到精通

lwenw22

我们怎么设计自己的DAO层的呢？
    看下示例，比如我要保存User对象，那么运用工厂模式和单例模式来设计DAO层。
DAO层接口：
package com.lwf.dao;
public interface IBaseDao {
  void   save(Object object);
}

DAO层接口实现，分MYSQL和ORACLE的实现

package com.lwf.dao;
public class BaseDao4MySql implements IBaseDao {
    public void save(Object object) {
        System.out.println("BaseDao4MySql");
    }
}
  

package com.lwf.dao;
public class BaseDao4Oracle implements IBaseDao {
    public void save(Object object) {
        System.out.println("BaseDao4Oracle");
    }
}            
工厂类，利用工厂得到DAO

package com.lwf.dao;
public class BaseDaoFactory {
    private static BaseDaoFactory baseDaoFactory = new BaseDaoFactory();
    private String baseDaoName;
    private BaseDaoFactory(){
         baseDaoName = "BaseDao4MySql";
        //加载xml属性
    }
   
    public static BaseDaoFactory getInstance(){
        return baseDaoFactory;
    }
   
    public IBaseDao getBaseDao(){
        IBaseDao iBaseDao = null;
        if(baseDaoName.equals("BaseDao4MySql")){
            iBaseDao = new BaseDao4MySql();
        }else if(baseDaoName.equals("BaseDao4Oracle")){
            iBaseDao = new BaseDao4Oracle();
        }
        return iBaseDao;
    }
}            
具体的业务：用户管理类：

package com.lwf.manager;
import com.lwf.bean.User;
import com.lwf.dao.BaseDaoFactory;
import com.lwf.dao.IBaseDao;
public class UserManager {
    private static BaseDaoFactory factory = BaseDaoFactory.getInstance();
    private static IBaseDao baseDao = factory.getBaseDao();
   
    public static void save(User user){
        baseDao.save(user);
    }
}

用户类：model

package com.lwf.bean;
public class User {
    private String name;
    private int age;
   
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public int getAge() {
        return age;
    }
    public void setAge(int age) {
        this.age = age;
    }
   
}         
下面是调用用户管理类的客户：

package com.lwf.client;
import com.lwf.bean.User;
import com.lwf.manager.UserManager;
public class Client {
    public static void main(String[] args) {
   
        User user = new User();
        user.setAge(11);
        user.setName("zhangshang");
        UserManager.save(user);
    }
}