Java 掷硬币游戏保存问题

我正在为一项任务创建一个掷硬币游戏，保存你的最后一个高分和名字。如果没有高分文件，程序运行正常，但如果有文件，程序将停止工作

import java.util.Scanner;
import java.io.File;
import java.io.FileWriter;
import java.io.PrintWriter;


public class BradySkuza43
{

public static void main( String[] args ) throws Exception
{
    Scanner keyboard = new Scanner(System.in);

    String coin, again, bestName, saveFile = "coin-flip-score.txt";
    int flip, streak = 0, best;

    File in = new File(saveFile);
    if ( in.createNewFile() )
    {
        System.out.println("Save game file doesn't exist. Created.");
        best = 1;
        bestName = " ";
    }
    else
    {
        Scanner input = new Scanner(in);
        bestName = input.next();
        best = input.nextInt();
        input.close();
        System.out.println("High score is " + best + " flips in a row by " + bestName );
    }

    do
    {
        flip = 1 + (int)(Math.random()*2);

        if ( flip == 1 )
        {
        coin = "HEADS";
        }
        else
        {
        coin = "TAILS";
        }

        System.out.println( "You flip a coin and it is... " + coin );

        if ( flip == 1 )
        {
            streak++;
            System.out.println( "\tThat's " + streak + " in a row...." );
            System.out.print( "\tWould you like to flip again (y/n)? " );
            again = keyboard.next();
        }
        else
        {
            streak = 0;
            again = "n";
        }
    } while ( again.equals("y") );

    System.out.println( "Final score: " + streak );

    if ( streak > best )
    {
        System.out.println("That's a new high score!");
        System.out.print("Your name: ");
        bestName = keyboard.next();
        best = streak;
    }
    else if ( streak == best )
    {
        System.out.println("That ties the high score. Cool.");
    }
    else
    {
        System.out.println("You'll have to do better than " + streak + "if you want a high score.");
    }


    PrintWriter out = new PrintWriter( new FileWriter(saveFile) );
    out.println(bestName);
    out.println(best);
    out.close();
}
}

---

当已经存在一个文件时，我得到一个NoTouchElement错误。我假设它与导入功能有关，但我不知道如何修复它。

以下是一些建议：

您的高分文件的名称不会更改，对吗？它不应该是一个变量，它应该是一个

静态final

变量

玩游戏，然后决定这是否是一个高分。因此，您应该有一个

getHighScore（）

方法（可以是

static

）

如果新分数是高分，则将其写入高分文件。应该有一个方法

静态writeHighScore（最终字符串名，最终整数分数）

所以我想把你的程序改成这样：

public class BradySkuza43
{
    public static final String HIGH_SCORE_FILE = "coin-flip-score.txt";

    public static void main( String[] args ) throws Exception
    {
        final Scanner keyboard = new Scanner(System.in);
        final int highScore = getHighScore();
        final int newScore = getScore(keyboard);

        if(newScore != 0 && newScore > highScore){
            final String name = getName(keyboard);
            writeHighScore(name, newScore);
    }

    private static int highScore(){
        // read high score from high score file or return Integer.MIN_VALUE if 
        //    no high score file exists
    }

    private static int getScore(final Scanner keyboard){
        // play game, prompt user, get input, etc. and then 
        //   return the player's score.
    }

    private static String getName(final Scanner keyboard){
        // prompt the user for their name and return their input
    }

    private static void writeHighScore(final String name, final int score){
        // write this high score (with the name) to the high score file
    }

}    

---

当已有文件（具有“最佳”值）时，读取“最佳”的方式似乎不正确。您可能正在寻找类似这样的内容（根据您的数据进行修改）来读取“保存的最佳值”

        BufferedReader reader = new BufferedReader(new FileReader(in));

        String readNumber = "";
        while (reader.readLine() != null) {
            readNumber += reader.readLine();
        }
        best = Integer.valueOf(readNumber);

---

最后不得不运行代码来查看保存文件是如何生成的。从文件（input.nextInt（））的第二次读取中看到NoTouchElement异常就指出了问题所在

如果你没有击败现有的连击（包括在第一次翻转时得到尾巴），你不会被提示输入名字。这会使保存文件被读取

\n
1
\n

默认情况下，扫描程序忽略空白。您不检查是否有可用的输入（hasNext方法）。当您在没有输入的情况下调用next（）或nextInt（）时，您将得到NoTouchElement。为什么会发生这种情况

逐行：

bestName = input.next();   <-- This is getting the "1" since there is a name saved
best = input.nextInt();    <-- since the 1 was already read, so there's nothing to get

---

如果出现问题，将停止代码运行，并停止添加一些调试语句以查看发生了什么

这是因为您创建了一个文件，该文件可能最终为空（如果您没有获得高分），然后您尝试读取该空文件。您不应该创建高分文件，除非您真的要写入它。或者你应该处理一个空的高分文件。

if(!foo.hasNext) { 
    System.out.println("foo should really have something here, but hasNext says it doesn't);
    System.exit();
}