由于代码太多，我会分为4个部分发这些代码，可以找我要源码
带dao后缀的都是一些方法，连接了SQL语句，主要是增删改查
（dao包里面有一些注释，供大家理解）
先写好DBHelper包，主要用于连接MySQL文件和MySQL数据
package com.zking.util;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;public class DBHelper {static {try {Class.forName("com.mysql.cj.jdbc.Driver");} catch (Exception e) {e.printStackTrace();}}public static Connection getCon() {try {return DriverManager.getConnection("jdbc:mysql://localhost:3306/user1?serverTimezone=GMT","root","123456");} catch (SQLException e) {e.printStackTrace();}return null;}public static void myClose(Connection con,PreparedStatement ps,ResultSet rs) {try {if(con!=null)con.close();if(ps!=null)ps.close();if(rs!=null)rs.close();} catch (Exception e) {e.printStackTrace();}}}
再写好实体类（food(食物类），sale（订单类）,Record（订单消费记录）,saleltem（订单详情）,user（用户）,cart(购物车),category（食物类型)
food
package com.zking.pojo;public class Food {private Integer id;private Integer cid;private String name;private Double price;private String cover;private String detail;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Integer getCid() {return cid;}public void setCid(Integer cid) {this.cid = cid;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}public String getCover() {return cover;}public void setCover(String cover) {this.cover = cover;}public String getDetail() {return detail;}public void setDetail(String detail) {this.detail = detail;}@Overridepublic String toString() {return "Food [id=" + id + ", cid=" + cid + ", name=" + name + ", price=" + price + ", cover=" + cover+ ", detail=" + detail + "]";}public Food(Integer id, Integer cid, String name, Double price, String cover, String detail) {super();this.id = id;this.cid = cid;this.name = name;this.price = price;this.cover = cover;this.detail = detail;}public Food() {super();// TODO Auto-generated constructor stub}}
Record
package com.zking.pojo;import java.sql.Date;public class Record {private Integer id;private Integer uid;private Double amount;private String kind;private Date trstime;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Integer getUid() {return uid;}public void setUid(Integer uid) {this.uid = uid;}public Double getAmount() {return amount;}public void setAmount(Double amount) {this.amount = amount;}public String getKind() {return kind;}public void setKind(String kind) {this.kind = kind;}public Date getTrstime() {return trstime;}public void setTrstime(Date trstime) {this.trstime = trstime;}@Overridepublic String toString() {return "Record [id=" + id + ", uid=" + uid + ", amount=" + amount + ", kind=" + kind + ", trstime=" + trstime+ "]";}public Record(Integer id, Integer uid, Double amount, String kind, Date trstime) {super();this.id = id;this.uid = uid;this.amount = amount;this.kind = kind;this.trstime = trstime;}public Record() {super();// TODO Auto-generated constructor stub}}
sale
package com.zking.pojo;import java.sql.Date;public class Sale {private Integer id;private String no;private Integer uid;private Double total;private Date createTime;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getNo() {return no;}public void setNo(String no) {this.no = no;}public Integer getUid() {return uid;}public void setUid(Integer uid) {this.uid = uid;}public Double getTotal() {return total;}public void setTotal(Double total) {this.total = total;}public Date getCreateTime() {return createTime;}public void setCreateTime(Date createTime) {this.createTime = createTime;}@Overridepublic String toString() {return "Sale [id=" + id + ", no=" + no + ", uid=" + uid + ", total=" + total + ", createTime=" + createTime+ "]";}public Sale(Integer id, String no, Integer uid, Double total, Date createTime) {super();this.id = id;this.no = no;this.uid = uid;this.total = total;this.createTime = createTime;}public Sale() {super();// TODO Auto-generated constructor stub}}
saleltem
package com.zking.pojo;public class SaleItem {private Integer id;private String sid;private Integer fid;private Integer num;private Double total;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getSid() {return sid;}public void setSid(String sid) {this.sid = sid;}public Integer getFid() {return fid;}public void setFid(Integer fid) {this.fid = fid;}public Integer getNum() {return num;}public void setNum(Integer num) {this.num = num;}public Double getTotal() {return total;}public void setTotal(Double total) {this.total = total;}@Overridepublic String toString() {return "SaleItem [id=" + id + ", sid=" + sid + ", fid=" + fid + ", num=" + num + ", total=" + total + "]";}public SaleItem(Integer id, String sid, Integer fid, Integer num, Double total) {super();this.id = id;this.sid = sid;this.fid = fid;this.num = num;this.total = total;}public SaleItem() {super();// TODO Auto-generated constructor stub}}
user
package com.zking.pojo;public class User {private Integer id;private String name;private String pwd;private Double money;private String ques;private String answer;private String avatar;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getPwd() {return pwd;}public void setPwd(String pwd) {this.pwd = pwd;}public Double getMoney() {return money;}public void setMoney(Double money) {this.money = money;}public String getQues() {return ques;}public void setQues(String ques) {this.ques = ques;}public String getAnswer() {return answer;}public void setAnswer(String answer) {this.answer = answer;}public String getAvatar() {return avatar;}public void setAvatar(String avatar) {this.avatar = avatar;}@Overridepublic String toString() {return "User [id=" + id + ", name=" + name + ", pwd=" + pwd + ", money=" + money + ", ques=" + ques+ ", answer=" + answer + ", avatar=" + avatar + "]";}public User(Integer id, String name, String pwd, Double money, String ques, String answer, String avatar) {super();this.id = id;this.name = name;this.pwd = pwd;this.money = money;this.ques = ques;this.answer = answer;this.avatar = avatar;}public User() {super();// TODO Auto-generated constructor stub}}
category
package com.zking.pojo;public class Category {private Integer id;private String name;private String en;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getEn() {return en;}public void setEn(String en) {this.en = en;}@Overridepublic String toString() {return "Category [id=" + id + ", name=" + name + ", en=" + en + "]";}public Category(Integer id, String name, String en) {super();this.id = id;this.name = name;this.en = en;}public Category() {super();// TODO Auto-generated constructor stub}}
cart
package com.zking.pojo;public class Cart {private Integer id;private Integer uid;private Integer fid;private Integer num;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Integer getUid() {return uid;}public void setUid(Integer uid) {this.uid = uid;}public Integer getFid() {return fid;}public void setFid(Integer fid) {this.fid = fid;}public Integer getNum() {return num;}public void setNum(Integer num) {this.num = num;}@Overridepublic String toString() {return "Cart [id=" + id + ", uid=" + uid + ", fid=" + fid + ", num=" + num + "]";}public Cart(Integer id, Integer uid, Integer fid, Integer num) {super();this.id = id;this.uid = uid;this.fid = fid;this.num = num;}public Cart() {super();// TODO Auto-generated constructor stub}}
之后再写这些东西要用到的方法，比如说用户查询，查询食品之类的，我简称dao包
cartdao
package com.zking.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import com.zking.pojo.Cart;
import com.zking.util.DBHelper;public class Cartdao {private Connection con;private PreparedStatement ps;private ResultSet rs;/*** 查询购物车** @param uid 用户id*/public List<Cart> list(int uid) {List<Cart> cs=new ArrayList<>();String sql="select * from cart where uid=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, uid);rs=ps.executeQuery();while(rs.next()) {Cart cc = new Cart();cc.setId(rs.getInt(1));cc.setUid(rs.getInt(2));cc.setFid(rs.getInt(3));cc.setNum(rs.getInt(4));cs.add(cc);}} catch (Exception e) {e.printStackTrace();}return cs;}/*** 查询购物车(根据用户id与商品id查询)* @param uid 用户编号* @param fid 商品编号*/public Cart get(int uid,int fid) {String sql="select * from cart where uid=? and fid=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, uid);ps.setInt(2, fid);rs=ps.executeQuery();if(rs.next()) {Cart cc = new Cart();cc.setId(rs.getInt(1));cc.setUid(rs.getInt(2));cc.setFid(rs.getInt(3));cc.setNum(rs.getInt(4));return cc;}} catch (Exception e) {e.printStackTrace();}return null;}//删除购物车的方法/*** 添加购物车** @param cart 购物车*/public int add(int uid,int fid) {String sql = "insert into cart(uid,fid,num) values(?,?,?)";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, uid);ps.setInt(2, fid);ps.setInt(3, 1);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 删除购物车** @param id 购物车编号*/public int del(int id) {String sql = "delete from cart where id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, id);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 更新购物车数量* @param id 购物车编号* @param num 购物车变动数量*/public int editNum(int id, int num) {String sql = "update cart set num=num+? where id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, num);ps.setInt(2, id);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 清空购物车* @param uid 用户编号*/public int delAll(int uid) {String sql = "delete from cart where uid=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, uid);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}}
categorydao
package com.zking.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import com.zking.pojo.Category;
import com.zking.util.DBHelper;public class CategoryDao {private Connection con;private PreparedStatement ps;private ResultSet rs;public List<Category> list(){List<Category> ds=new ArrayList<>();try {con=DBHelper.getCon();String sql = "select * from category";ps=con.prepareStatement(sql);rs=ps.executeQuery();while(rs.next()) {Category c=new Category();c.setId(rs.getInt(1));c.setName(rs.getString(2));c.setEn(rs.getString(3));ds.add(c);}} catch (Exception e) {e.printStackTrace();}return ds;}/*** 根据id查询单个分类*/public Category findById(int cid) {String sql = "select * from category where id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, cid);rs=ps.executeQuery();while(rs.next()) {Category c=new Category();c.setId(rs.getInt(1));c.setName(rs.getString(2));c.setEn(rs.getString(3));return c;}} catch (Exception e) {e.printStackTrace();}return null;}//根据id查询商品的个数public int findConut(int cid) {String sql = "select count(*)from food a inner join category b on a.cid=b.cid where b.id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, cid);rs=ps.executeQuery();while(rs.next()) {int cc=rs.getInt(1);return cc;}} catch (Exception e) {e.printStackTrace();}return 0;}}
fooddao
package com.zking.pojo;public class Food {private Integer id;private Integer cid;private String name;private Double price;private String cover;private String detail;private Integer up;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public Integer getCid() {return cid;}public void setCid(Integer cid) {this.cid = cid;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Double getPrice() {return price;}public void setPrice(Double price) {this.price = price;}public String getCover() {return cover;}public void setCover(String cover) {this.cover = cover;}public String getDetail() {return detail;}public void setDetail(String detail) {this.detail = detail;}public Integer getUp() {return up;}public void setUp(Integer up) {this.up = up;}@Overridepublic String toString() {return "Food [id=" + id + ", cid=" + cid + ", name=" + name + ", price=" + price + ", cover=" + cover+ ", detail=" + detail + ", up=" + up + "]";}public Food(Integer id, Integer cid, String name, Double price, String cover, String detail, Integer up) {super();this.id = id;this.cid = cid;this.name = name;this.price = price;this.cover = cover;this.detail = detail;this.up = up;}public Food() {super();// TODO Auto-generated constructor stub}}
recordao
package com.zking.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import com.zking.pojo.Record;
import com.zking.util.DBHelper;public class RecorDao {private Connection con;private PreparedStatement ps;private ResultSet rs;//查询所有的消费记录//v:全部，充值，消费public List<Record> list(int uid,String v){List<Record> ds=new ArrayList<>();try {con=DBHelper.getCon();String sql="select *from record where uid=? ";if(v!=null&&!v.equals("全部")) {sql+="and kind='"+v+"'";//and Kind='充值'//and Kind='消费'}ps=con.prepareStatement(sql);ps.setInt(1, uid);rs=ps.executeQuery();while(rs.next()) {Record r=new Record();r.setId(rs.getInt(1));r.setUid(rs.getInt(2));r.setAmount(rs.getDouble(3));r.setKind(rs.getString(4));r.setTrstime(rs.getDate(5));ds.add(r);}} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}return ds;}public int add (Record r){String sql="insert into record(uid,amount,kind)values(?,?,?)";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, r.getUid());ps.setDouble(2,r.getAmount());ps.setString(3, r.getKind());return ps.executeUpdate();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}return 0;}
}
seledao
package com.zking.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import com.zking.pojo.Sale;
import com.zking.util.DBHelper;public class SaleDao {private Connection con;private PreparedStatement ps;private ResultSet rs;/*** 查询所有订单* @param uid 用户编号*/public List<Sale> list(int uid) {List<Sale> ss=new ArrayList<>();String sql = "select * from sale where uid=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, uid);rs=ps.executeQuery();while(rs.next()) {Sale sale=new Sale();sale.setId(rs.getInt(1));sale.setNo(rs.getString(2));sale.setUid(rs.getInt(3));sale.setTotal(rs.getDouble(4));sale.setCreateTime(rs.getDate(5));ss.add(sale);}} catch (Exception e) {e.printStackTrace();}return ss;}/*** 添加订单*/public int add(Sale sale) {String sql = "insert into sale(no,uid,total) values(?,?,?)";try {con = DBHelper.getCon();ps = con.prepareStatement(sql);ps.setString(1, sale.getNo());ps.setInt(2, sale.getUid());ps.setDouble(3, sale.getTotal());return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 删除订单*/public int del(String no) {String sql = "delete from sale where no=?";try {con = DBHelper.getCon();ps = con.prepareStatement(sql);ps.setString(1, no);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}}
SaleItemDao
package com.zking.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;import com.zking.pojo.SaleItem;
import com.zking.util.DBHelper;public class SaleItemDao {private Connection con;private PreparedStatement ps;private ResultSet rs;/*** 根据订单编号查询订单项目* @param sid 订单编号*/public List<SaleItem> list(String sid) {String sql = "select * from sale_item where sid=?";List<SaleItem> ss=new ArrayList<>();try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setString(1, sid);rs=ps.executeQuery();while(rs.next()) {SaleItem si=new SaleItem();si.setId(rs.getInt(1));si.setSid(rs.getString(2));si.setFid(rs.getInt(3));si.setNum(rs.getInt(4));si.setTotal(rs.getDouble(5));ss.add(si);}} catch (Exception e) {e.printStackTrace();}return ss;}/*** 添加订单*/public int add(SaleItem item) {String sql = "insert into sale_item(sid,fid,num,total) values(?,?,?,?)";try {con = DBHelper.getCon();ps = con.prepareStatement(sql);ps.setString(1, item.getSid());ps.setInt(2, item.getFid());ps.setInt(3, item.getNum());ps.setDouble(4, item.getTotal());return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 删除订单*/public int del(String no) {String sql = "delete from sale_item where sid=?";try {con = DBHelper.getCon();ps = con.prepareStatement(sql);ps.setString(1, no);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}}
userdao
package com.zking.dao;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;import com.zking.pojo.User;
import com.zking.util.DBHelper;public class Userdao {private Connection con;private PreparedStatement ps;private ResultSet rs;/*** 登录*/public User login(User user) {String sql = "select * from user where name=? and pwd=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setString(1, user.getName());ps.setString(2, user.getPwd());rs=ps.executeQuery();if(rs.next()) {User u=new User();u.setId(rs.getInt(1));u.setName(rs.getString(2));u.setPwd(rs.getString(3));u.setMoney(rs.getDouble(4));u.setQues(rs.getString(5));u.setAnswer(rs.getString(6));return u;}} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}return null;}/*** 添加用户*/public int add(User user) {String sql = "insert into user(name,pwd,ques,answer,avatar) values(?,?,?,?,?)";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setString(1, user.getName());ps.setString(2, user.getPwd());ps.setString(3, user.getQues());ps.setString(4, user.getAnswer());ps.setString(5, user.getAvatar());return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 根据用户名查找用户（用于查询用户的密保）*/public User findByName(String name) {String sql = "select * from user where name=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setString(1, name);rs=ps.executeQuery();if(rs.next()) {User u=new User();u.setId(rs.getInt(1));u.setName(rs.getString(2));u.setPwd(rs.getString(3));u.setMoney(rs.getDouble(4));u.setQues(rs.getString(5));u.setAnswer(rs.getString(6));return u;}} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}return null;}/*** 修改用户密码*/public int editPwd(User user) {String sql = "update user set pwd=? where name=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setString(1, user.getPwd());ps.setString(2, user.getName());return ps.executeUpdate();} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}return 0;}
//根据id查询用户方法（用于刷新用户数据）//uid 用户idpublic User getById(int uid) {String sql="select *from user where id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setInt(1, uid);rs=ps.executeQuery();if(rs.next()) {User u=new User();u.setId(rs.getInt(1));u.setName(rs.getString(2));u.setPwd(rs.getString(3));u.setMoney(rs.getDouble(4));u.setQues(rs.getString(5));u.setAnswer(rs.getString(6));u.setAvatar(rs.getString(7));return u;}} catch (Exception e) {// TODO: handle exceptione.printStackTrace();}return null;}//修改用户信息public int edit(User user) {String sql="update user set name=?,pwd=?,ques=?,answer=?,avatar=?,where id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setString(1, user.getName());ps.setString(2, user.getPwd());ps.setString(3, user.getQues());ps.setString(4, user.getAnswer());ps.setString(5, user.getAvatar());ps.setInt(6, user.getId());return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;}/*** 修改用户余额** @param uid 用户id* @param money 变动的钱*/
public int editMoney(int uid, double money) {String sql = "update user set money=money+? where id=?";try {con=DBHelper.getCon();ps=con.prepareStatement(sql);ps.setDouble(1, money);ps.setInt(2, uid);return ps.executeUpdate();} catch (Exception e) {e.printStackTrace();}return 0;
}}
由于代码太多，我会分为4个部分发这些代码，可以找我要源码，还有就是我学习Java只学习了3个月，这是第一个比较大的项目，不喜勿喷
