11月27日每日学习

package dao;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Random;
import java.util.Scanner;

import util.DBUtil;
public class Dao {

    static int num;
    static String []s=new String [100];
    public static void main(String args[]) throws Exception{
        menu();
        Scanner sc=new Scanner(System.in);
        int choose=sc.nextInt();
        if(choose==1)
        {
            setQustion();
        }else if(choose==2)
        {
            getQuestion();
        }
        sc.close();
        
    }
    //创建运算式题目
    public static String creat(){
        int x,y,z;
        Random rand=new Random();
        x= rand.nextInt(100)+1;
        y=rand.nextInt(100)+1;
        z=rand.nextInt(4)+1;
        String str="";
        if (z==1){
            num=x+y;
            str=x+"+"+y;
            return str;
        }else if(z==2){
            num=x-y;
            str=x+"-"+y;
        }else if(z==3){
            num=x*y;
            str=x+"*"+y;
        }else if(z==4){
            num=x/y;
            str=x+"/"+y;
        }
        return str;
    }
        //判断算式是否重复，包括反向的重复
    public static boolean test(String w,int i){
        String w1=new StringBuffer(w).reverse().toString();
        for (int j=0;j<i;j++){
            if (w.equals(s[j])&&w1.equals(s[j])){
                return true;
            }
        }
        return false;
    }
    
    public static void menu()
    {
        System.out.println("请选择你要进行的操作");
        System.out.println("1.生成题目并将题目存到数据库中");
        System.out.println("2.从数据库中读取数据");
        System.out.print("请输入您的操作(1/2)");
    }
    public static void getQuestion()throws Exception
    {
        Connection connection =DBUtil.getConnection();
        String sql="select question from que;";
        PreparedStatement pstm=null;
        pstm = connection.prepareStatement(sql);

        ResultSet rs = pstm.executeQuery();
        while(rs.next())
        {
            String question=rs.getString("question");
            System.out.println(question);
        }
        System.out.println("是否选择获取答案(1是/2否)");
        Scanner sc=new Scanner(System.in);
        int flag=sc.nextInt();
        if(flag==1)
        {
            getDaan();
        }
        sc.close();
        DBUtil.close(connection);
        DBUtil.close(pstm);
    }
    public static void getDaan()throws Exception{
        Connection connection =DBUtil.getConnection();
        PreparedStatement pstm=null;
        String sql="select daan from que;";
        pstm=connection.prepareStatement(sql);
        
        ResultSet rs=pstm.executeQuery();
        while(rs.next())
        {
            String n=rs.getString("daan");
            System.out.println(n);
        }
        DBUtil.close(connection);
        DBUtil.close(pstm);
    }
    public static void setQustion() throws Exception
    {
        //连接数据库
        Connection connection= DBUtil.getConnection();
        Scanner sc=new Scanner(System.in);
        System.out.println("请输入存储的题目个数:");
        int n= sc.nextInt();
        String sql=null;
        PreparedStatement pstmt = null;
        try {
            for (int i=0;i<n;i++){
                String question=creat();
                if (test(question,i)){
                    continue;  //如果重复就跳过循环，不进行存入
                }
                sql="insert into que values(?,?)";
                
                pstmt =connection.prepareStatement(sql);
                
                pstmt.setString(1, question);
                pstmt.setString(2, Double.toString(num));
                pstmt.executeUpdate();
                System.out.println(question+"  "+num);
                
                sql="";
                
            }
        }finally {
            DBUtil.close(connection);
            DBUtil.close(pstmt);
            sc.close();
        }
    }

}