不同数据库访问抽象工厂模式实现

// 用户客户端访问，解除与具体数据库访问的耦合
public interface IUser {
    void Insert(User user);
    User GetUser(int id);
}
// 用于访问SQLServer的User
public class SqlServerUser implements IUser {
    @Override
    public void Insert(User user) {
        // TODO Auto-generated method stub
        System.out.println("在SqlServer中给User新增一条记录");
    }
    @Override
    public User GetUser(int id) {
        // TODO Auto-generated method stub
        System.out.println("在SqlServer中根据ID获取到User一条记录");        
        return null;
    }
//用于访问AccessUser的User
public class AccessUser implements IUser {
    @Override
    public void Insert(User user) {
        // TODO Auto-generated method stub
        System.out.println("在Access中给User新增一条记录");
    }
    @Override
    public User GetUser(int id) {
        // TODO Auto-generated method stub
        System.out.println("在Access中根据ID获取到User一条记录");        
        return null;
    }
}
//定义一个创建访问User表对象的抽象的工厂接口
public interface IFactory {
    IUser CreateUser();
}
// 实例化SqlServerUser
public class SqlServerFactory implements IFactory {
    @Override
    public IUser CreateUser() {
        // TODO Auto-generated method stub
        return new SqlServerUser();
    }
}
// 实例化AccessUser
public class AccessFactory implements IFactory {
    @Override
    public IUser CreateUser() {
        // TODO Auto-generated method stub
        return new AccessUser();
    }
}
public class Test {
    public static void main(String[] args) {
        // 使用Access
        User user =new User();
        IFactory factory = new AccessFactory();
        IUser iu = factory.CreateUser();
        iu.Insert(user);
        iu.GetUser(1);
        // 使用SqlServer
        User user1 =new User();
        IFactory factory1 = new SqlServerFactory();
        IUser iu1 = factory1.CreateUser();
        iu1.Insert(user1);
        iu1.GetUser(1);
    }
}