jdbc 链接数据库

创建一个user类是要与数据库的属性一致作为

java类必须和mysql对应上

创建 Bean包

创建user类

package Dao.bean;

import java.io.Serializable;

public class User implements Serializable{
    
    
    private int id;//用户名编号
    private  String userName;//用户名
    private String loginName;//登录名
    private String password;//密码
    private int sex;//用户的性别
    private String identityCode;//用户身份证号
    private String email;//用户邮箱
    private String mobile;//用户手机号
    private int type;//用户的类型1管理员 0普通用户
    
    
    public User() {
        super();
    }

    public String toString() {
        return "User [id=" + id + ", userName=" + userName + ", loginName="
                + loginName + ", password=" + password + ", sex=" + sex
                + ", identityCode=" + identityCode + ", email=" + email
                + ", mobile=" + mobile + ", type=" + type + "]";
    }
    
    
        public User(int id, String userName, String loginName, String password,
            int sex, String identityCode, String email, String mobile, int type) {
        super();
        this.id = id;
        this.userName = userName;
        this.loginName = loginName;
        this.password = password;
        this.sex = sex;
        this.identityCode = identityCode;
        this.email = email;
        this.mobile = mobile;
        this.type = type;
    }
        public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getUserName() {
        return userName;
    }
    public void setUserName(String userName) {
        this.userName = userName;
    }
    public String getLoginName() {
        return loginName;
    }
    public void setLoginName(String loginName) {
        this.loginName = loginName;
    }
    public String getPassword() {
        return password;
    }
    public void setPassword(String password) {
        this.password = password;
    }
    public int getSex() {
        return sex;
    }
    public void setSex(int sex) {
        this.sex = sex;
    }
    public String getIdentityCode() {
        return identityCode;
    }
    public void setIdentityCode(String identityCode) {
        this.identityCode = identityCode;
    }
    public String getEmail() {
        return email;
    }
    public void setEmail(String email) {
        this.email = email;
    }
    public String getMobile() {
        return mobile;
    }
    public void setMobile(String mobile) {
        this.mobile = mobile;
    }
    public int getType() {
        return type;
    }
    public void setType(int type) {
        this.type = type;
    }
        

         
}

创建News类

package Dao.bean;

import java.io.Serializable;
import java.util.Date;

public class News implements Serializable{
     private int id;//新闻编号
     private String  title;//新闻标题
     private String  content;//新闻内容
     private Date createTime;//创建时间
     private String img;//新闻的图片
    @Override
    public String toString() {
        return "News [id=" + id + ", title=" + title + ", content=" + content
                + ", createTime=" + createTime + ", img=" + img + "]";
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getTitle() {
        return title;
    }
    public void setTitle(String title) {
        this.title = title;
    }
    public String getContent() {
        return content;
    }
    public void setContent(String content) {
        this.content = content;
    }
    public Date getCreateTime() {
        return createTime;
    }
    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
    public String getImg() {
        return img;
    }
    public void setImg(String img) {
        this.img = img;
    }
    public News(int id, String title, String content, Date createTime,
            String img) {
        super();
        this.id = id;
        this.title = title;
        this.content = content;
        this.createTime = createTime;
        this.img = img;
    }
    public News() {
        super();
    }
}

创建一个dao层包

创建一个UserDao接口

package Dao.dao;

import java.io.Serializable;
import java.util.List;

import Dao.bean.User;



/**
 * 
 * 用户的增删改查
 *
 */
public interface UserDao extends BaseDao<User>{
	
	User login(String loginName,String  password);
         
	
}

　　创建一个NewsDao接口

package Dao.dao;

import java.io.Serializable;
import java.util.List;

import Dao.bean.News;
import Dao.bean.User;

public interface NewsDao extends BaseDao<News> {
	
    
}

　　创建一个BaseDao接口

让 UserDao 和 NewsDao 实现 BaseDao

package Dao.dao;

import java.io.Serializable;
import java.util.List;

import Dao.bean.News;
import Dao.bean.User;


public interface BaseDao<T> {
	 int add(T t);
	 
     int delete(Serializable id);
     
     int update(T t);
     
     List<T> findAll();
     
     T findById(Serializable id);
		
}

　　创建impl包

和创建Userimpl类

package Dao.impl;

import java.io.Serializable;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import Dao.bean.User;
import Dao.dao.UserDao;
import Dao.util.JdbcUtil;
import Dao.util.ResultSetUtil;

public class UserDaoImpl extends JdbcUtil implements UserDao {

    /**
     * 登录
     */
    @Override
    public User login(String loginName, String password) {
        String sql = "select * from easybuy_user where loginName=? and password=?";
        // 给参数赋值
        Object[] params = { loginName, password };
        User user = null;
        try {
            rs = myExcuteQuery(sql, params);
            user = ResultSetUtil.findById(rs, User.class);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection();
        }
        return user;
    }

    /**
     * 现在网址注册 一般都是 用户名 密码 +邮箱/手机号
     * 之后用户的详细信息 可以进行完善
     */
    @Override
    public int add(User t) {
        String sql = "insert into easybuy_user(userName,loginName,password,sex,identityCode,email,mobile,type) values(?,?,?,?,?,?,?,?)";
        Object[] params = { t.getUserName(), t.getLoginName(), t.getPassword(),
                t.getSex(), t.getIdentityCode(), t.getEmail(), t.getMobile(),
                t.getType() };
        int rowNum = 0;
        try {
            rowNum = myExcuteUpdate(sql, params);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rowNum;
    }

    /**
     * 因为用户有可能根据id删除对象，也有可能是根据其他的选择！
     * 我们不确定类型，所以就把参数类型设置为Serializable
     * 
     * 遗留问题？
     * id为空  根据name删除
     * name为空  根据id删除
     */
    @Override
    public int delete(Serializable id) {
        String sql = "delete from easybuy_user where id=?";
        Object[] params = { id };
        int rowNum = 0;
        try {
            rowNum = myExcuteUpdate(sql, params);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rowNum;
    }

    /**
     * 修改
     *    我们怎么知道用户到底修改了什么？
     */
    @Override
    public int update(User t) {
        String sql = "update easybuy_user set loginName=?,password=? where id=?";
        Object[] params = { t.getLoginName(), t.getPassword(), t.getId() };
        int rowNum = 0;
        try {
            rowNum = myExcuteUpdate(sql, params);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        return rowNum;
    }

    @Override
    public List<User> findAll() {
        String sql = "select * from easybuy_user";
        // 创建一个集合来保存所有的用户
        List<User> users = new ArrayList<>();
        try {
            rs = myExcuteQuery(sql);
            users = ResultSetUtil.findAll(rs, User.class);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection();
        }
        return users;
    }

    /**
     * 查询指定的用户信息
     */
    @Override
    public User findById(Serializable userID) {
        String sql = "select * from easybuy_user where id=?";
        // 给参数赋值
        Object[] params = { userID };
        User user = null;
        try {
            rs = myExcuteQuery(sql, params);
            user = ResultSetUtil.findById(rs, User.class);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection();
        }
        return user;
    }
}

创建Nwesimpl类

package Dao.impl;

import java.io.Serializable;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;

import Dao.bean.News;
import Dao.bean.News;
import Dao.bean.detail;
import Dao.bean.order;
import Dao.dao.NewsDao;
import Dao.dao.NewsDao;
import Dao.util.JdbcUtil;
import Dao.util.ResultSetUtil;

public class NewsDaoImp extends JdbcUtil implements NewsDao{
    public int add(News t) {
        String sql="insert into easybuy_News(title,content,createTime,img) values(?,?,?,?)";
        Object[] param={t.getTitle(),t.getContent(),t.getCreateTime(),t.getImg()};
        int rowNum=0;
        
        try {
            rowNum=myExcuteUpdate(sql, param);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            closeConnection();
        }
        
        return rowNum;
    }

    //删除
    public int delete(Serializable id) {
        String sql="delete from easybuy_News where id=?";
        Object[]params={id};
        try {
            myExcuteUpdate(sql,params);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            closeConnection();
        }
        return 0;
    }

    //修改
    public int update(News t) {
        String sql="update easybuy_News set title='?',content='?' where id=?";
        Object[] params={t.getTitle(),t.getContent(),t.getId()};
        int rowNum=0;
        try {
            rowNum=myExcuteUpdate(sql, params);
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            closeConnection();
        }
        return rowNum;
    }

    //查询
    public List<News> findAll() {
        String sql="select* from easybuy_News";
        List<News> Newss=new ArrayList<>();
        try {
            rs=myExcuteQuery(sql);
            Newss=ResultSetUtil.findAll(rs,News.class);
//            while(rs.next()){
//                int id=rs.getInt("id");
//                String title=rs.getString("title");
//                String content=rs.getString("content");
//                Date createTime=rs.getTimestamp("createTime");
//                String img=rs.getString("img");
//                News News=new News(id,title,content,createTime,img);
//                Newss.add(News);
        
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            closeConnection();
        }
        
        
        
        return Newss;
    }

    //登录
    public News login(String loginName, String password) {
        String sql="select *from  easybuy_News  where loginName=? and password=?";
        News News=null;
        Object[] params={loginName,password};
        
            try {
                rs=myExcuteQuery(sql, params);
                News=ResultSetUtil.findById(rs, News.class);
//                if(rs.next()){
//                    int id=rs.getInt("id");
//                    String title=rs.getString("title");
//                    String content=rs.getString("content");
//                    Date createTime=rs.getTimestamp("createTime");
//                    String img=rs.getString("img");
//                     News=new News(id, title, content, createTime, img); 
//                }
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }finally{
                closeConnection();
            }
            return News;
    }
    
    public News findById(Serializable id) {
        String sql = "select * from easybuy_user where id=?";
        // 给参数赋值
        Object[] params = { id };
        News news = null;
        try {
            rs = myExcuteQuery(sql, params);
            news = ResultSetUtil.findById(rs, News.class);
        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            closeConnection();
        }
        return news;

    }


}

创建serverce包

创建BaseServiceService接口

package Dao.serverce;

import java.io.Serializable;
import java.util.List;

import Dao.bean.User;

public interface BaseService{
	
}

创建serverce包

创建NewsService接口

package Dao.serverce;

import Dao.bean.News;




public interface NewsService {
    
}

创建serverce包

创建UserService接口

package Dao.serverce;
import java.io.Serializable;
import java.util.List;

import Dao.bean.User;

public interface UserService {


		User login(String loginName, String password);

		

		/**
		 * 新增
		 */
		void add(User t);

		/**
		 * 删除
		 */
		void delete(Serializable id);

		/**
		 * 修改
		 */
		void update(User t);

		/**
		 * 查询所有
		 */
		List<User> findAll();
		/**
		 * 指定查询
		 */
		
		User findById(Serializable id);


	
}

创建DaoServic包

创建Userimpl类

package Dao.servic.imp;

import java.io.Serializable;
import java.sql.SQLException;
import java.util.List;

import org.apache.poi.util.SystemOutLogger;

import utilclass.UtilClass;

import com.sun.istack.internal.logging.Logger;

import Dao.bean.News;
import Dao.bean.User;
import Dao.dao.UserDao;
import Dao.impl.UserDaoImpl;
import Dao.serverce.NewsService;
import Dao.serverce.UserService;
import Dao.util.JdbcUtil;
import Dao.util.MemcachedUtil;


public class UserImpServic  implements UserService{
   
		// 实例化dao层对象 但是这种方式不可取 是耦合的！
		UserDao dao = new UserDaoImpl();
		 private static Logger logger= Logger.getLogger(UserImpServic.class);
		/**
		 * 登录
		 */
		@Override
		public User login(String loginName, String password) {
			User user = dao.login(loginName, password);
			if (user == null) {
				 logger.info("登录失败");

				
				return null;
			} else {
				 logger.info("用户登录成功！");
				return user;
			}
		}

	    

		public void add(User t) {
			int rowNum = dao.add(t);
			if (rowNum > 0) {
				 logger.info("新增成功");
			} else {
				 logger.info("新增失败");
			}
			
		}

		public void delete(Serializable id) {
			if(MemcachedUtil.getInstance().get("myUser")==null){
				  System.out.println("进入了数据查询");
				  int user=dao.delete(id);
				  //放入缓存中
				  MemcachedUtil.getInstance().set("myUser",10,user);
				    
			}else{
				System.out.println("进入了缓存中查询");
			 MemcachedUtil.getInstance().get("myUser");
			}
			
			

		}
		public void update(User t) {  
				int user=dao.update(t);	

		}
		
		public List<User> findAll() {
			  if(MemcachedUtil.getInstance().get("myUser")==null){
				     System.out.println("进入了数据查询");
				     List<User> user=dao.findAll();
				     MemcachedUtil.getInstance().set("myUser",10,user);
				     return user;
			  }else{
				     System.out.println("进入了缓存中查询");
				     return  (List<User>) MemcachedUtil.getInstance().get("myUser");
			 }
		}
		
		public User findById(Serializable id) {
			if(MemcachedUtil.getInstance().get("myUser")==null){
				  System.out.println("进入了数据查询");
				  User user=dao.findById(id);
				  //放入缓存中
				  MemcachedUtil.getInstance().set("myUser",10,user);
				  return user;
			}else{
				System.out.println("进入了缓存中查询");
				return(User) MemcachedUtil.getInstance().get("myUser");
			}
			
		}
		

	public static void main(String[] args) {
		UserImpServic use=new UserImpServic();
		 User s=new User();
		
		 
		try {
			System.out.println(use.findById(53));
		} catch (Throwable e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
//		try {
//			new UtilClass().util_java();
//		} catch (SQLException e) {
//			// TODO Auto-generated catch block
//			e.printStackTrace();
//		}
//		
	}

}

创建Newsimpl类

package Dao.servic.imp;

import java.io.Serializable;
import java.util.List;

import Dao.bean.News;
import Dao.serverce.NewsService;
import Dao.util.JdbcUtil;



public class NewsImpServic implements NewsService{

}

创建text包

创建ResultDemo类

package Dao.text;

import java.io.Serializable;
import java.util.List;
import java.util.Scanner;

import Dao.bean.User;
import Dao.dao.UserDao;
import Dao.impl.UserDaoImpl;
import Dao.serverce.UserService;
import Dao.servic.imp.UserImpServic;

import java.util.Scanner;



/**
 * 相当于我们后续的jsp动态页面
 */
public class Resultshow {
	private static Scanner input = new Scanner(System.in);
	
	public static void main(String[] args) {
		showMenu();
	}

	/**
	 * 一级菜单
	 */
	public static void showMenu() {
		System.out.println("欢迎进入用户和新闻管理系统");
		System.out.println("1:用户管理");
		System.out.println("2:新闻管理");
		System.out.println("请您选择：");
		int choose = input.nextInt();
		switch (choose) {
		case 1: // 用户管理
			showUser();
			break;
		}
	}

	/**
	 * 用户管理菜单
	 */
	private static void showUser() {
		// 实例化UserService层的对象
		UserService service = new UserImpServic();
		User u=new User();
		System.out
				.println("========================================================");
		System.out.println("欢迎进入用户管理系统");
		System.out.println("1:登录");
		System.out.println("2:删除");
		System.out.println("3:修改");
		System.out.println("4:查询所有");
		System.out.println("5:查询指定用户信息");
		System.out.println("6:返回上级目录");
		System.out.println("请您选择：");
		int choose = input.nextInt();
		switch (choose) {
		case 1: // 登录
			userLogin(service);
			break;
		case 2: // 删除
			userDelete(service);
			break;
		case 3: // 修改
			updates(service);
			break;
		case 4: // 查询所有
			Alllist(service);
			
		
			break;
		case 5: // 查询指定用户信息
			userLogin(service);
			break;
		case 6: // 返回上级目录
			showMenu();
			break;
		}

	}

	private static void Alllist(UserService service) {
		List<User> user=service.findAll();
		for (User user2 : user) {
			int id=user2.getId();
			String name=user2.getLoginName();
			String Email=user2.getEmail();
			String Password=user2.getPassword();
			String bile=user2.getMobile();
			String Code=user2.getIdentityCode();
			
			System.out.println("您的个人信息如下：");
			System.out.println(id);
			System.out.println(name);
			System.out.println(Email);
			System.out.println(Password);
			System.out.println(bile);
			System.out.println(Code);
		}
	}

	private static void updates(UserService service) {
		User u=new User();
		System.out.println("请输入id进行修改：");
		int id = input.nextInt();
		System.out.println("请您输入要修改的第一个内容：");
		String Name = input.next();
		System.out.println("请您输入要修改的第二个内容：");
		String pas = input.next();
		u.setLoginName(Name);
		u.setPassword(pas);
		u.setId(id);
		service.update(u);
	}

	public static void userDelete(UserService service) {
		System.out.println("请您输入需要删除的ID：");
		int id = input.nextInt();
		service.delete(id);
	}

	// 用户登录
	public static void userLogin(UserService service) {
		System.out.println("请您输入用户名：");
		String loginName = input.next();
		System.out.println("请您输入密码：");
		String password = input.next();
		User user = service.login(loginName, password);
		System.out.println("您的个人信息如下：");
		System.out.println(user.getId());
		System.out.println(user.getLoginName());
		System.out.println(user.getPassword());
		System.out.println(user.getEmail());
		System.out.println(user.getMobile());
		System.out.println(user.getIdentityCode());
	}

}

　　创建jdbcUtil包公共包

创建ConfigManager公共类

package Dao.util;
import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;





/**
 * 读取properties文件的单例类
 */
//public class ConfigManager {
//
//	// 01.创建本类的静态变量
//	private static ConfigManager manager = new ConfigManager();
//
//	private static Properties properties;
//
//	// 02.私有化构造
//
//	private ConfigManager() {
//		// 实例化Properties对象
//		properties = new Properties();
//		InputStream stream = ConfigManager.class.getClassLoader()
//				.getResourceAsStream("jdbc.properties");
//		// 加载properties文件
//		try {
//			properties.load(stream);
//		} catch (IOException e) {
//			e.printStackTrace();
//		} finally {
//			try { // 关闭流
//				stream.close();
//			} catch (IOException e) {
//				e.printStackTrace();
//			}
//		}
//	}
//
//	// 03.对外提供访问的接口
//	public static synchronized ConfigManager getInstance() {
//		return manager;
//	}
//
//	// 04.让用户传递一个文件中的key 我们返回文件中的value
//	public static String getValue(String key) {
//		return properties.getProperty(key);
//	}
//
//}

public class ConfigManager {

	// 01.创建本类的静态变量
	private static ConfigManager manager = new ConfigManager();

	private static Properties properties;

	// 02.私有化构造
	private ConfigManager() {
		// 实例化Properties对象
		properties = new Properties();
		InputStream stream = ConfigManager.class.getClassLoader()
				.getResourceAsStream("jdbc.properties");
		// 加载properties文件
		try {
			properties.load(stream);
		} catch (IOException e) {
			e.printStackTrace();
		} finally {
			try { // 关闭流
				stream.close();
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}

	// 03.对外提供访问的接口
	public static synchronized ConfigManager getInstance() {
		return manager;
	}

	// 04.让用户传递一个文件中的key 我们返回文件中的value
	public static String getValue(String key) {
		return properties.getProperty(key);
	}

}

　　创建jdbcUtil公共类

package Dao.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;




/**
 * 
 * 所有JDBC操作数据库的工具类
 * 01.数据库四要素的获取
 * 02.开启连接
 * 03.关闭连接
 * 04.公共的增删改
 * 05.公共的查询
 */


public class JdbcUtil {

	protected static Connection connection = null; // 便于我们释放资源
	protected static PreparedStatement statement = null;
	protected static ResultSet rs = null; // 查询数据返回的结果集

	/**
	 *  获取连接
	 */
	public static boolean getConnection() throws ClassNotFoundException,
			SQLException {
		try {
			// 通过反射机制获取数据库驱动包
			Class.forName(ConfigManager.getInstance().getValue("jdbc.driver"));
			// 通过DriverManager获取Conncetion连接对象
			connection = DriverManager.getConnection(ConfigManager
					.getInstance().getValue("jdbc.url"), ConfigManager
					.getInstance().getValue("jdbc.userName"), ConfigManager
					.getInstance().getValue("jdbc.password"));
		} catch (Exception e) {
			e.printStackTrace();
			return false;
		}
		return true;
	}

	/**
	 * 释放资源
	 */
	public static void closeConnection() {
		if (rs != null) {
			try {
				rs.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		if (statement != null) {
			try {
				statement.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
		if (connection != null) {
			try {
				connection.close();
			} catch (SQLException e) {
				e.printStackTrace();
			}
		}
	}

	/**
	 * 公共的增删改
	 * 
	 *  select * from student
	 *  select * from student where id=?
	 *  select * from student where id=? or name=?
	 *  
	 *  我们可以确定的是有sql语句！因为只有sql语句才能操作数据库！
	 *  但是我么无法确定的是：
	 *     01.参数的个数
	 *     02.参数的类型
	 * 
	 *  我们应该是考虑有参数 还是 没有参数？  有参数的！
	 *  考虑有1个参数还是有N个参数？     有N个参数的！
	 *  
	 *  用户需要传递一个执行的sql语句
	 *           再传递一个参数列表！
	 * @throws SQLException 
	 * @throws ClassNotFoundException 
	 */
	
	
	public static int myExcuteUpdate(String sql, Object... param)
			throws ClassNotFoundException, SQLException {
		int rowNum = 0;
		if (getConnection()) { // 证明有连接
			statement = connection.prepareStatement(sql);
			for (int i = 0; i < param.length; i++) { // 给sql语句中的? 一个一个赋值
				statement.setObject(i + 1, param[i]);
			}
			rowNum = statement.executeUpdate();
		}
		closeConnection(); // 释放资源
		return rowNum;
	}

	/**
	 * 公共的查询
	 */
	public static ResultSet myExcuteQuery(String sql, Object... param)
			throws ClassNotFoundException, SQLException {
		if (getConnection()) { // 证明有连接
			statement = connection.prepareStatement(sql);
			for (int i = 0; i < param.length; i++) { // 给sql语句中的? 一个一个赋值
				statement.setObject(i + 1, param[i]);
			}
			rs = statement.executeQuery();
		}
		/**
		 * 在这里不能事先关闭资源，因为子类中有rs的具体使用  还需要用到连接！
		 * 子类使用完毕，自行了断！
		 */
		return rs;
	}
}

　　创建MemcachedUtil公共类

package Dao.util;

import java.io.IOException;
import java.net.InetSocketAddress;

import net.spy.memcached.MemcachedClient;

public class MemcachedUtil {
	//01.私有化本类对象
           private static MemcachedUtil util;
           private static MemcachedClient client=null;
           static{
        	   util=new MemcachedUtil();
        	   try {
				client=new MemcachedClient(new InetSocketAddress("127.0.0.1",11211));
			} catch (IOException e) {
				// TODO Auto-generated catch block
				e.printStackTrace();
			}
        
           }
           //私有化构造
           private MemcachedUtil(){
        	   
           }
           //对外提供访问的接口
           public static MemcachedClient getInstance(){
			return client;  
   
           }
      
}

　　创建ResultSetUtil公共类

package Dao.util;

import java.lang.reflect.Field;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/**
 *01.我们从数据库中获取的结果集就是ResultSet
 *02.结果集中的类型我们确定吗？？？？   不确定 ===》 T
 *03.sql语句一旦执行T的类型就确定了！
 *04.通过反射机制 向实体类中的属性赋值
 */
public class ResultSetUtil {

	/**
	 * 01.务必需要一个结果集 ResultSet ,才能获取T的类型
	 * 02.反射务必需要Class<T>
	 **/
	public static <T> T findById(ResultSet rs, Class<T> c) {
		T object = null;
		try {
			if (rs.next()) {
				object = c.newInstance(); // 实例化对象
				Field[] fields = c.getDeclaredFields(); // 获取实体类中所有的属性
				for (Field field : fields) {
					field.setAccessible(true); // 打开权限
					field.set(object, rs.getObject(field.getName()));
				}
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
		return object;
	}

	public static <T> List<T> findAll(ResultSet rs, Class<T> c) {
		T object = null;
		List<T> list = new ArrayList(); // 创建集合 保存每一个对象
		try {
			while (rs.next()) {
				object = c.newInstance(); // 实例化对象
				Field[] fields = c.getDeclaredFields();
				for (Field field : fields) {
					field.setAccessible(true); // 打开权限
					field.set(object, rs.getObject(field.getName()));
				}
				// 将对象加入到集合
				list.add(object);
			}
		} catch (SQLException e) {
			e.printStackTrace();
		} catch (InstantiationException e) {
			e.printStackTrace();
		} catch (IllegalAccessException e) {
			e.printStackTrace();
		}
		return list;
	}

}

　　要导入包

创建jdbc.properties文件

posted @ 2018-04-19 18:51 久不见阅读(114) 评论(0) 收藏举报

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