package per.sww.page;

import per.sww.tools.ScannerChoice;

public class MainPage extends ScannerChoice{
    public static void main(String[] args) {
        MainPage.mianPage();
    }
    
    /**
     * No.1
     * 实现登录界面
     * 且实现退出功能
     */
    public static void mianPage(){
        System.out.println("---------------------------\n");
        System.out.println("\t 1.商品维护\n");
        System.out.println("\t 2.前台收银\n");
        System.out.println("\t 3.商品管理\n");
        System.out.println("\t 0.退出程序\n");
        System.out.println("---------------------------\n");
        System.out.println("\n请输入选项:");
        do{
            //MainPage继承了ScannerChoice,在此处调用Scanner的ScannerInfoString方法
            String choice = ScannerInfoString();
            //创建一个正则验证输入
            String regex = "[0-3]";
            if(choice.matches(regex)){
                int info = Integer.parseInt(choice);
                switch (info) {
                case 0:
                    System.out.println("---------------------------\n");
                    System.out.println("您已退出!");
                    System.exit(1);
                    break;
                case 1:
                    MaintenancePage();
                    break;
                case 2:
                    checkstandLogPage();
                    break;
                case 3:
                    commodityManagementPage();
                    break;
                default:
                    break;
                }
            }
            System.out.println("输入有误请重新输入:");
        }while(true);
    }
    /**
     * No.4
     * 主页面中[商品管理]选项类
     */
    private static void commodityManagementPage() {
        System.out.println("---------------------------\n");
        System.out.println("\t 1.售货员管理\n");
        System.out.println("\t 2.列出当日卖出列表\n");
        System.out.println("---------------------------\n");
        System.out.println("\n请输入选项,或者按 0 返回上一级菜单.");
    }
    /**
     * No.3
     * 主页面中[前台收银]选项类
     */
    private static void checkstandLogPage() {
        System.out.println("---------------------------\n");
        System.out.println("■■■■■■■■■■■■■■■■■欢迎购物■■■■■■■■■■■■■■■■■");
        System.out.println("\t 1.登录系统\n");
        System.out.println("\t 2.退出\n");
        System.out.println("---------------------------\n");
    }

    /**
     * No.2
     * 主页面中[商品维护]选项类
     */
    public static void MaintenancePage(){
        System.out.println("---------------------------\n");
        System.out.println("\t 0.退出程序\n");
        System.out.println("\t 1.添加商品\n");
        System.out.println("\t 2.更改商品\n");
        System.out.println("\t 3.删除商品\n");
        System.out.println("\t 4.查询商品\n");
        System.out.println("\t 5.显示所有商品\n");
        System.out.println("---------------------------\n");
        System.out.println("\n请输入选项,或者按 0 返回上一级菜单.");
        do{
            String choice = ScannerInfoString();
            String regex = "[0-3]";
            if(choice.matches(regex)){
                int info = Integer.parseInt(choice);
                switch (info) {
                case 0:
                    mianPage();
                    System.exit(1);
                    break;
                case 1:
                    GoodsPage.addGoodsPage();
                    break;
                case 2:
                    GoodsPage.upateGoodsPage();
                    break;
                case 3:
                    GoodsPage.deleteGoodsPage();
                    break;
                case 4:
                    GoodsPage.queryGoodsPage();
                    break;
                case 5:
                    GoodsPage.displayGoodsPage();
                    break;
                default:
                    break;
                }
            }
            System.out.println("输入有误请重新输入:");
        }while(true);
    }
}

package per.sww.page;

import java.util.ArrayList;

import per.sww.dao.GoodsDao;
import per.sww.entity.Goods;
import per.sww.tools.QueryPrint;
import per.sww.tools.ScannerChoice;
import sun.security.util.Length;

public final class GoodsPage extends ScannerChoice {

    public static void addGoodsPage() {
        System.out.println("\t正在执行添加商品操作\n");

        System.out.println("\n請輸入添加商品-名称");
        String goodName = ScannerInfoString();
        System.out.println("\n請輸入添加商品-价格");
        double goodPrice = ScannerInfo();
        System.out.println("\n請輸入添加商品-数量");
        int goodNumber = ScannerNum();

        Goods goods = new Goods(goodName, goodPrice, goodNumber);
        boolean bool = new GoodsDao().addGoods(goods);
        if (bool) {
            System.out.println("\n\t!您已成功添加商品到数据库!");
        } else {
            System.out.println("添加商品失败");
        }
        changedInfoNext("addGoodsPage");
    }

    /**
     * 2.更改商品界面
     */
    public static void upateGoodsPage() {
        System.out.println("\t正在执行 更改商品 操作\n");
        System.out.println("请输入想要更改的商品名字");

        int gid = QueryPrint.Query("upateGoodsPage");

        System.out.println("\n--------请选择您要更改的内容\n");
        System.out.println("\t1.更改商品-名称");
        System.out.println("\t2.更改商品-价格");
        System.out.println("\t3.更改商品-数量");
        System.out.println("\n请输入选项,或者按0返回上一级菜单.");
        do {
            String choice = ScannerInfoString();
            String regex = "[0-3]";
            if (choice.matches(regex)) {
                int info = Integer.parseInt(choice);
                switch (info) {
                case 0:
                    MainPage.MaintenancePage();
                    break;
                case 1:
                    System.out.println("请输入商品-新名称");
                    String gname = ScannerInfoString();
                    Goods goodname = new Goods(gid, gname);
                    Boolean boolName = new GoodsDao().updateGoods(1, goodname);
                    if (boolName) {
                        System.out.println("成功");
                    } else {
                        System.out.println("失败");
                    }
                    changedInfoNext("upateGoodsPage");
                    break;
                case 2:
                    System.out.println("请输入商品-新价格 ");
                    double gPrice = ScannerInfo();
                    Goods goodsPrice = new Goods(gid, gPrice);
                    boolean boolPrice = new GoodsDao().updateGoods(2, goodsPrice);
                    if (boolPrice) {
                        System.out.println("成功");
                    } else {
                        System.out.println("失败");
                    }
                    changedInfoNext("upateGoodsPage");
                    break;
                case 3:
                    System.out.println("请输入商品-新数量 ");
                    int num=ScannerNum();
                    Goods goodsnum=new Goods(gid, num);
                    boolean boolnum=new GoodsDao().updateGoods(3, goodsnum);
                    if(boolnum){
                        System.out.println("成功");
                    }else {
                        System.out.println("失败");
                    }
                    changedInfoNext("upateGoodsPage");
                    break;
                default:
                    System.out.println("请输入正确选项:");
                    break;
                }
            }
            System.out.println("重新输入");
        } while (true);
    }

    /**
     * 3.删除商品界面
     */
    public static void deleteGoodsPage() {
        System.out.println("\t正在执行 删除商品 操作\n");
        System.out.println("请输入想要删除的商品名字");
        int gid = QueryPrint.Query("deleteGoodsPage");
        do {
            System.out.println("\n确认删除该商品：Y/N");
            String choice = ScannerInfoString();
            if ("y".equals(choice) || "Y".equals(choice)) {
                boolean bool = new GoodsDao().deleteGoods(gid);
                if (bool) {
                    System.err.println("删了");
                } else {
                    System.out.println("你坑了");
                }
                changedInfoNext("deleteGoodsPage");
            } else if ("n".equals(choice) || "N".equals("choice")) {
                MainPage.MaintenancePage();
            }
            System.out.println("输错了");
        } while (true);

    }
    
    /**
     * 查询商品
     */
    public static void queryGoodsPage(){
        System.out.println("\t\t  正在执行查询商品操作\n");
        System.out.println("\t\t1.按照商品 数量升序 查询");
        System.out.println("\t\t2.按照商品 价格升序 查询");
        System.out.println("\t\t3.输入商品  关键字  查询");
        System.out.println("\n请输入选项,或者按0返回上一级菜单.");
        do{
            String info=ScannerInfoString();
            String regex="[0-3]";
            if(info.matches(regex)){
                int choice=Integer.parseInt(info);
                switch (choice) {
                case 0:
                    MainPage.MaintenancePage();
                    break;
                case 1:
                case 2:
                case 3:
                    if(choice==3){
                        System.out.println("\t\t正在执行商品  关键字  查询操作\n");
                        System.out.println("\n请输入商品关键字");
                    }
                    ArrayList<Goods> goodList=new GoodsDao().queryGoods(choice);
                    if(goodList==null || goodList.size()<=0){
                        System.out.println("不存在");
                        queryGoodsPage();
                    }else {
                        if(choice==1){
                            System.out.println("\t\t\t\t\t商品按照 数量升序 列表\n\n");
                        } else if (choice == 2) {
                            System.out.println("\t\t\t\t\t商品按照 价格升序 列表\n\n");
                        } else {
                            System.out.println("\t\t\t\t\t您所查找的商品如下\n\n");
                        }
                        System.out.println("\t商品编号\t\t商品名称\t\t商品价格\t\t商品数量\t\t备注\n");
                        
                        for (int i = 0 ,length =goodList.size(); i < length; i++) {
                            Goods goods=goodList.get(i);
                            System.out.print("\t" + goods.getGid() + "\t\t"
                                    + goods.getGname() + "\t\t"
                                    + goods.getGprice() + "\t\t"
                                    + goods.getGnum());
                            int gnum=goods.getGnum();
                            if(gnum==0){
                                System.out.println("\t\t该商品已售空！");
                            }else if(gnum < 10) {
                                System.out.println("\t\t该商品已不足10件");
                            }else {
                                System.out.println("\t\t-");
                            }
                            System.out.println("\t");
                        }
                        System.out.println("---------------------");
                        do {
                            System.out.println("输入 0 返回上一级菜单");
                            String choiceNext=ScannerInfoString();
                            if("0".equals(choiceNext)){
                                MainPage.MaintenancePage();
                            }
                            System.err.println("输入有误！");
                        } while (true);
                    }
                    break;
                default:
                    break;
                }
                break;
            }
            System.err.println("输入有误！");
            System.out.println("请重新选择,或者按0返回上一级菜单.");
        }while(true);
        
        System.out.println("\n\n输入 0 返回上一级菜单");
        boolean boolNext=true;
        do {
            String choice=ScannerInfoString();
            if("0".equals(choice)){
                boolNext=false;
                queryGoodsPage();
            }
            System.err.println("!输入有误!");
            System.out.println("请输入 0 返回上一级菜单");
        } while (boolNext);
    }
    
    /**
     * 查询所有商品
     */
    public static void displayGoodsPage(){
        System.out.println("\t\t\t\t\t所有商品列表\n\n");
        ArrayList<Goods> goodlist=new GoodsDao().displayGoods();
        if(goodlist.size()<0){
            System.err.println("！库存为空！");
            MainPage.MaintenancePage();
        }else{
            System.out.println("\t商品编号\t\t商品名称\t\t商品价格\t\t商品数量\t\t备注\n");
            for(int i=0,length=goodlist.size();i<length;i++){
                Goods goods=goodlist.get(i);
                System.out.print("\t" + goods.getGid() + "\t\t"
                        + goods.getGname() + "\t\t" + goods.getGprice()
                        + " $\t\t" + goods.getGnum());
                int gnum=goods.getGnum();
                if(gnum==0){
                    System.out.println("\t\t该商品已售空！");
                }else if (gnum<0) {
                    System.out.println("\t\t该商品已不足10件");
                }else if (gnum<10) {
                    System.out.println("\t\t-");
                }else {
                    System.out.println("\t");
                }
                System.out.println("\t");
                
                
                System.out.println("---------------------");
                do{
                    System.out.println("输入 0 返回上一级菜单");
                    String choice=ScannerInfoString();
                    if("0".equals(choice)){
                        MainPage.MaintenancePage();
                    }
                    System.out.println("输入有误");
                }while(true);
                
                
            }
        }
    }
}

package per.sww.tools;

import java.util.Scanner;

import per.sww.page.GoodsPage;
import per.sww.page.MainPage;

public class ScannerChoice {
    /**
     * 获取键盘录入
     */
    public static String ScannerInfoString(){
        Scanner scanner=new Scanner(System.in);
        System.out.print("请输入：");
        return scanner.next();
    }
    
    
    /**
     * 键盘录入价格
     * @return
     */
    public static double ScannerInfo(){
        double num=0.00;
        do{
            Scanner sc=new Scanner(System.in);
            System.out.println("小数点后两位");
            String info=sc.next();
            //验证小数的正则
            String regex="(([1-9][0-9]*)\\.([0-9]{2}))|[0]\\.([0-9]{2})";
            if(info.matches(regex)){
                num=Double.parseDouble(info);
            }else{
                System.out.println("输入有误!");
                continue;
            }
            break;
        }while(true);
        return num;
    }
    
    public static int ScannerNum(){
        int num=0;
        String regex="([1-9])|([1-9][0-9]+)";
        do{
            Scanner sc=new Scanner(System.in);
            System.out.println("请输入:");
            String nums=sc.next();
            if(nums.matches(regex)){
                num=Integer.parseInt(nums);
            }else{
                System.out.println("输入有误请重新输入:");
                continue;
            }
            break;
        }while(true);
        return num;
    }
    
    
    
    /**
     * 获取用户-更改完商品-下一步 获取用户-删除完商品-下一步 获取用户-添加完商品-下一步
     * 
     * @param 调用者
     */
    public static void changedInfoNext(String oper){
        do{
            System.out.println("是否继续进行-当前操作:(Y/N)");
            String chioe=ScannerChoice.ScannerInfoString();
            if("y".equals(chioe) || "Y".equals(chioe)){
                if("upateGoodsPage".equals(oper)){
                    GoodsPage.upateGoodsPage();
                }else if ("deleteGoodsPage".equals(oper)) {
                    GoodsPage.deleteGoodsPage();
                }else if ("addGoodsPage".equals(oper)) {
                    GoodsPage.addGoodsPage();
                }
            }else if ("N".equals(oper)) {
                MainPage.MaintenancePage();
            }
            System.out.println("\n输入有误！请重新输入.");
        }while(true);
    }
}

package per.sww.entity;

public final class Goods {
    private int gid;
    private String gname;
    private double gprice;
    private int gnum;
    /**
     * 添加商品信息
     * 
     * @param gname
     *            ,gprice,gum
     */
    public Goods(String gname,double gprice,int gnum){
        this.gname=gname;
        this.gprice=gprice;
        this.gnum=gnum;
    }
    /**
     * 展示所有商品
     * 
     * @param gid
     *            ,gname,gprice,gum
     */
    public Goods(int gid,String gname,double gprice,int gnum){
        this.gid=gid;
        this.gname=gname;
        this.gprice=gprice;
        this.gnum=gnum;
    }
    
    
    /**
     * 根据编号更改商品信息
     * 
     * @param gid
     *            ,gum
     */
    public Goods(int gid, String    gname){
        this.gid=gid;
        this.gname=gname;
    }
    
    /**
     * 根据编号更改商品价格
     */
    public Goods(int gid,double gprice){
        this.gid=gid;
        this.gprice=gprice;
    }
    
    
    /**
     * 根据编号更改商品信息
     * 
     * @param gid
     *            ,gprice
     */
    public Goods(int gid,int gnum){
        this.gid=gid;
        this.gnum=gnum;
    }
    
    
    public int getGid() {
        return gid;
    }
    public void setGid(int gid) {
        this.gid = gid;
    }
    public String getGname() {
        return gname;
    }
    public void setGname(String gname) {
        this.gname = gname;
    }
    public double getGprice() {
        return gprice;
    }
    public void setGprice(double gprice) {
        this.gprice = gprice;
    }
    public int getGnum() {
        return gnum;
    }
    public void setGnum(int gnum) {
        this.gnum = gnum;
    }
}

package per.sww.entity;

public final class SalesMan {
    private int sId;
    private String sName;
    private String sPassword;
    
    public SalesMan(int sId,String sName){
        this.sId=sId;
        this.sName=sName;
    }
    
    public SalesMan(int sId,String sName,String sPassword){
        this.sId=sId;
        this.sName=sName;
        this.sPassword=sName;
    }
    
    public SalesMan(String sName,String sPassword){
        this.sName=sName;
        this.sPassword=sPassword;
    }
    
    
    //封装
    public int getsId() {
        return sId;
    }
    public void setsId(int sId) {
        this.sId = sId;
    }
    public String getsName() {
        return sName;
    }
    public void setsName(String sName) {
        this.sName = sName;
    }
    public String getsPassword() {
        return sPassword;
    }
    public void setsPassword(String sPassword) {
        this.sPassword = sPassword;
    }
}

package per.sww.dao;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import per.sww.db.DbClose;
import per.sww.db.DbConn;
import per.sww.entity.Goods;
import per.sww.tools.ScannerChoice;

public final class GoodsDao {
    Connection conn = null;
    PreparedStatement ps = null;
    ResultSet rs = null;

    /**
     * 1.添加商品到数据库goods表
     * 
     * @param goods
     *            商品对象
     * @return boolean
     */
    public boolean addGoods(Goods goods) {
        boolean bool = false;
        conn = DbConn.getconn();
        String sql = "INSERT INTO GOODS(GNAME,GPRICE,GNUM) VALUES(?,?,?)";

        try {
            ps = conn.prepareStatement(sql);
            ps.setString(1, goods.getGname());
            ps.setDouble(2, goods.getGprice());
            ps.setInt(3, goods.getGnum());
            int rs = ps.executeUpdate();

            if (rs > 0) {
                bool = true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DbClose.addClose(ps, conn);
        }
        return bool;

    }
    
    public ArrayList<Goods> queryGoods(int key){
        ArrayList<Goods> goodlist=new ArrayList<Goods>();
        conn=DbConn.getconn();
        switch (key) {
        case 1:
            String sqlGnum = "SELECT * FROM GOODS ORDER BY GNUM ASC";//排序查询,升序
            try{
                ps=conn.prepareStatement(sqlGnum);
                rs=ps.executeQuery();
                while(rs.next()){
                    int gid=rs.getInt("gid");
                    String gname=rs.getString(2);
                    double gprice=rs.getDouble(3);
                    int gnum=rs.getInt(4);
                    
                    Goods goods=new Goods(gid, gname, gprice, gnum);
                    goodlist.add(goods);
                }
            }catch (SQLException e) {
                e.printStackTrace();
            }finally {
                DbClose.queryClose(ps, rs, conn);
            }
            break;
        //降序
        case 2:
            String sqlGprice = "SELECT * FROM GOODS ORDER BY GPRICE ASC";
            try {
                ps=conn.prepareStatement(sqlGprice);
                rs=ps.executeQuery();
                while(rs.next()){
                    int gid=rs.getInt("gid");
                    String gname=rs.getString(2);
                    double gprice=rs.getDouble(3);
                    int gnum=rs.getInt(4);
                    
                    Goods goods=new Goods(gid, gname, gprice, gnum);
                    goodlist.add(goods);
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }finally {
                DbClose.queryClose(ps, rs, conn);
            }
            
            break;
        case 3:
            String nameGet=ScannerChoice.ScannerInfoString();
            String sqlGname="SELECT * FROM GOODS WHERE GNAME LIKE '%'||?||'%'";
            try {
                ps=conn.prepareStatement(sqlGname);
                ps.setString(1, nameGet);
                rs=ps.executeQuery();
                while(rs.next()){
                    int gid=rs.getInt("gid");
                    String gname=rs.getString(2);
                    double gprice=rs.getDouble(3);
                    int gnum=rs.getInt(4);
                    
                    Goods goods=new Goods(gid, gname, gprice, gnum);
                    goodlist.add(goods);
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }finally {
                DbClose.queryClose(ps, rs, conn);
            }
            break;
        case 4:
            break;
        default:
            break;
        }
        return goodlist;
        
    }

    /**
     * 3.从数据库goods表中-刪除商品
     * 
     * @param gid
     *            商品编号
     * @return boolean
     */
    public boolean deleteGoods(int gid) {
        boolean bool = false;
        conn = DbConn.getconn();
        String sql = "DELETE FROM GOODS WHERE GID=?";
        try {
            ps = conn.prepareStatement(sql);
            ps.setInt(1, gid);
            int rs = ps.executeUpdate();
            if (rs > 0) {
                bool = true;
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DbClose.addClose(ps, conn);
        }
        return bool;
    }

    /**
     * 更改商品信息到数据库goods表
     * @param key
     * @param goods
     * @return
     */
    public boolean updateGoods(int key,Goods goods){
        boolean bool=false;
        conn=DbConn.getconn();
        switch (key) {
        case 1:
            String sqlNAME="UPDATE GOODS SET GNAME=? WHERE GID=?";
            try {
                ps=conn.prepareStatement(sqlNAME);
                ps.setString(1,goods.getGname());
                ps.setInt(2, goods.getGid());
                int rs=ps.executeUpdate();
                if(rs>0){
                    bool=true;
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }finally {
                DbClose.addClose(ps, conn);
            }
            break;
            
            case 2:
                String sqlgprice="UPDATE GOODS SET GPRICE=? WHERE GID=?";
                try{
                    ps=conn.prepareStatement(sqlgprice);
                    ps.setDouble(1, goods.getGprice());
                    ps.setInt(2, goods.getGid());
                    int rs=ps.executeUpdate();
                    if(rs>0){
                        bool=true;
                    }
                }catch (SQLException e) {
                    e.printStackTrace();
                }finally {
                    DbClose.addClose(ps, conn);
                }
                break;
                
            case 3:
                String sqlgnum="UPDATE GOODS SET GNUM=? WHERE GID=?";
                try {
                    ps=conn.prepareStatement(sqlgnum);
                    ps.setInt(1, goods.getGnum());
                    ps.setInt(2, goods.getGid());
                    int rs=ps.executeUpdate();
                    if(rs>0){
                        bool=true;
                    }
                } catch (SQLException  e) {
                    e.printStackTrace();
                }finally {
                    DbClose.addClose(ps, conn);
                }
        default:
            break;
        }
        return bool;
    }
    
    
    public ArrayList<Goods> displayGoods(){
        ArrayList<Goods> goodList=new ArrayList<Goods>();
        conn=DbConn.getconn();
        String sql="SELECT * FROM GOODS";
        try{
            ps=conn.prepareStatement(sql);
            rs=ps.executeQuery();
            while (rs.next()) {
                int gid=rs.getInt(1);
                String gname=rs.getString(2);
                double gprice=rs.getDouble(3);
                int gnum=rs.getInt(4);
                Goods goods=new Goods(gid, gname, gprice, gnum);
                goodList.add(goods);
            }
        }catch(SQLException e){
            e.printStackTrace();
        }finally {
            DbClose.queryClose(ps, rs, conn);
        }
        return goodList;
        
    }

}

package per.sww.db;

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

public final class DbClose {
    public static void addClose(PreparedStatement ps, Connection conn) {
        try {
            if (ps != null) {
                ps.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            if (conn != null) {
                conn.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
    
    public static void queryClose(PreparedStatement ps,ResultSet rs, Connection conn){
        try{
            if (ps!=null) {
                ps.close();
            }
        }catch(SQLException e){
            e.printStackTrace();
        }
        try {
            if(rs!=null){
                rs.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
        try {
            if(conn!=null){
                conn.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

package per.sww.db;

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

public class DbConn {
    public static Connection getconn(){
        Connection conn=null;
        String user="root";
        String password="root";
        String url="jdbc:mysql://localhost:3306/shop?useUnicode=true&characterEncoding=utf-8";
        
        try{
            Class.forName("com.mysql.jdbc.Driver");
            conn=DriverManager.getConnection(url, user, password);
        }catch(SQLException e){
            e.printStackTrace();
        }catch (ClassNotFoundException e) {
            e.printStackTrace();
        }
        return conn;
    }
}

package per.sww.tools;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;

import per.sww.db.DbClose;
import per.sww.db.DbConn;
import per.sww.entity.Goods;

public final class QueryPrint {
    Connection conn=null;
    PreparedStatement ps=null;
    ResultSet rs=null;
    
    
    public static int Query(String oper){
        int gid=-1;
        String shopping=ScannerChoice.ScannerInfoString();
        ArrayList<Goods> goodlist=new QueryPrint().queryGoodsKey(-1, shopping);
        if (goodlist==null || goodlist.size()<=0) {
            System.out.println("\t！！无此商品 ！！");
            
            ScannerChoice.changedInfoNext(oper);
        }else {
            Goods goods=goodlist.get(0);
            System.out.println("\t\t\t\t\t商品列表\n\n");
            System.out.println("\t商品编号\t\t商品名称\t\t商品价格\t\t商品数量\t\t备注\n");
            System.out.print("\t" + goods.getGid() + "\t\t" + goods.getGname()
            + "\t\t" + goods.getGprice() + "\t\t" + goods.getGnum());
            if (goods.getGnum()==0) {
                System.out.println("\t\t该商品已售空");
            }else if(goods.getGnum()<10){
                System.out.println("\t\t该商品已不足10件");
            }else {
                System.out.println("\t\t-");
            }
            gid=goods.getGid();
            
        }
        return gid;
        
        
    }
    
    public ArrayList<Goods> queryGoodsKey(int gId,String gName){
        ArrayList<Goods> goodlist=new ArrayList<Goods>();
        conn=DbConn.getconn();
        String sql="SELECT * FROM GOODS WHERE GID=? OR GNAME=?";
        try{
            ps=conn.prepareStatement(sql);
            ps.setInt(1, gId);
            ps.setString(2, gName);
            rs=ps.executeQuery();
            while (rs.next()) {
                int gid=rs.getInt("gid");
                String gname=rs.getString(2);
                double gprice=rs.getDouble(3);
                int gnum=rs.getInt(4);
                
                Goods goods=new Goods(gid, gname, gprice, gnum);
                goodlist.add(goods);
            }
        }catch(SQLException e){
            e.printStackTrace();
        }finally {
            DbClose.addClose(ps, conn);
        }
        return goodlist;
    }
}