我的猜数游戏，Java写的，嗯，不太好，请求指导。

package guess;
import java.util.Scanner;
import javax.swing.JOptionPane;
public class C22 {

private static Scanner in;//系统自动帮我改的，可能我也不太会这个输入，慢慢来...

public static void main(String[] args) {
System.out.println("-------Game begin-------");
System.out.println("Please choose what u want:\n");
System.out.println("1.play\n");//开始游戏
System.out.println("2.introduction\n");//说明书
System.out.println("3.end\n");//结束 以上为菜单。
int i=0;
do{
in = new Scanner(System.in);//用scanner函数在键盘把m赋值
int m;
m=in.nextInt();
switch(m)//对应菜单打出1.2.3.
{
case 1:
{
int realNumber=(int)(Math.random()*1000+1);//获得1~1000随机数
int yourGuess=0;//定义用户猜数的初始值
int count=1;//count记录猜数次数。
String
str=JOptionPane.showInputDialog("Please input your answer:");
yourGuess=Integer.parseInt(str);
while(yourGuess!=realNumber)
{
count++;
if(count>10)//大于十次猜数，游戏结束。
{
System.out.println("Game over!");
break;
}
if(yourGuess>realNumber)
{
str=JOptionPane.showInputDialog("try smaller,guess again,please!\nThis is your"+count+"st time");
yourGuess=Integer.parseInt(str);
}
else if(yourGuess<realNumber)
{
str=JOptionPane.showInputDialog("try bigger,guess again,please!\nThis is your"+count+"st time");
yourGuess=Integer.parseInt(str);
}

System.out.println("Your answer:\n"+yourGuess);
}
System.out.println("The chance u cost is :"+(count-1));
System.out.println("The real answer:\n"+realNumber);
}break;
case 2:
{
System.out.println("This is a game about guess number, you have 10 times to guess the true random number,and have a good luck\n");//说明书
}break;
case 3:
{
i++;
}break;
default:
break;

}

}while(i!=1);

}

}