import java.util.Random;
import javax.swing.JOptionPane;
public class MyRandom
{
 public static void main(String[] args)
 {
 //生成隨機數
 Random randomNumber = new Random();
 int myNum = randomNumber.nextInt(10);
 String guessNum = "";
 int guessNumber = 0;
 //猜對猜錯的標識
 boolean sign = false;
 //猜數字的循環
 do{
 try{
 guessNum = JOptionPane.showInputDialog(null,"歡迎來到猜數字游戲！,請輸入數字");
 guessNumber = Integer.parseInt(guessNum);
 if(guessNumber > myNum)
 {
 JOptionPane.showMessageDialog(null,"猜大了");
 } 
 else if(guessNumber < myNum)
 {
 JOptionPane.showMessageDialog(null,"猜小了");
 }
 else
 {
 sign = true;
 }
 }catch(NumberFormatException e){
 JOptionPane.showMessageDialog(null,"輸入格式錯誤");
 }
 }while(guessNumber != myNum);
 
 if(sign)
 {
 JOptionPane.showMessageDialog(null,"恭喜你猜對了!");
 }
 }
}

import javax.swing.JOptionPane;
import java.util.ArrayList;
import java.util.Random;

public class ComRandom
{
 //給猜的數設置一個范圍
 int low = 0, high = 10;
 boolean leave = false;
 public void run()
 {
 int myIntNumber = 0;
 String myNumber;
 try{
 //給電腦一個數讓他猜
 myNumber = JOptionPane.showInputDialog(null,"給我一個0-10的數字，讓我（電腦）來猜");
 try{
 myIntNumber = Integer.parseInt(myNumber);
 }catch(NumberFormatException e){
 JOptionPane.showMessageDialog(null,"異常");
 leave = true;

 }
 }catch(NullPointerException e){
 
 JOptionPane.showMessageDialog(null,"拜拜");
 }
 
 if(!leave){
 //電腦隨機猜一次，生成一個隨機的數字
 Random randomGenerator= new Random();
 int guessNumber = randomGenerator.nextInt(10);
 //循環判斷電腦猜的數字是大還是小
 //定義兩個字符串，提示電腦是猜大了還是猜小了。
 String output = "";
 try{
 output = JOptionPane.showInputDialog(null,"是" + guessNumber + "！我猜對了嗎？");
 while(!output.equals("猜對了"))
 {
 if(output.equals("猜大了"))
 {
 guessNumber = guessNumber(guessNumber,myIntNumber);
 }
 else if(output.equals("猜小了"))
 {
 guessNumber = guessNumber(guessNumber, myIntNumber);
 }
 else
 {
 JOptionPane.showMessageDialog(null,"我沒聽懂你在說什么...");
 }
 
 try{
 output = JOptionPane.showInputDialog(null,"是" + guessNumber + "！我猜對了嗎？");
 }catch(NullPointerException e)
 {
 JOptionPane.showMessageDialog(null,"異常");
 }
 }
 }catch(NullPointerException e){
 JOptionPane.showMessageDialog(null,"異常");
 }
 }
 leave = false;
 }
 
 /**
 * 二分法猜數字
 */
 private int guessNumber(int guess,int number)
 {
 if(guess < number)
 {
 //答案是5 我猜的是2
 low = guess + 1;
 }
 else if(guess > number)
 {
 //答案是6我猜的是8
 high = guess - 1;
 }
 guess = (high + low) / 2;
 return guess;
 }
}