如何在存储前 10 名得分和得分球员姓名的 txt 文件上创建“高分列表”？

Question

我需要在 txt 文件中制作高分列表。 在第一个游戏中，txt 文件应该是空的，因为它是第一个游戏。 第一场比赛结束后，得分列表必须每次都用球员的名字和球员的得分进行更新。 名单当然要根据玩家的得分从高到低排序。 10 场比赛后，应删除最后一场比赛，列表中应仅保留 10 场比赛。

我正在尝试这样做，但每次我的 txt 文件都为空。 我该如何解决这个问题？

我的高分 class：

import java.io.FileWriter;
import java.io.IOException;
import java.util.Scanner;
import java.util.Formatter;
import java.nio.file.Paths;

public class HighScore {

    public class HighScoreEntry {
        private String name;
        private int score;

        public HighScoreEntry(String name, int score) {
            this.name = name;
            this.score = score;
        }

        public String getName() {
            return name;
        }

        public int getScore() {
            return score;
        }
    }

    public void writeHighScores(HighScoreEntry[] highScores) {
        Formatter f = null;
        FileWriter fw = null;
        try {
            fw = new FileWriter("highscores.txt",true);
            f = new Formatter(fw);
            for (int i = 0; i < highScores.length; i++) {
                f.format("%s:%d%n", highScores[i].getName(), highScores[i].getScore());
            }
        } catch (IOException e) {
            System.out.println("An error occurred while writing the high scores file.");
        } finally {
            if (f != null) {
                f.close();
            }
        }
    }
    
    public HighScoreEntry[] readHighScores() {
        HighScoreEntry[] highScores = new HighScoreEntry[10];
    
        // Initialize the high scores array with default values
        for (int i = 0; i < highScores.length; i++) {
            highScores[i] = new HighScoreEntry("", 0);
        }
        
        Scanner reader = null;

        try {
            reader = new Scanner(Paths.get("highscores.txt"));
            int i = 0;
            while (reader.hasNextLine() && i < 10) {
                String line = reader.nextLine();
                String[] parts = line.split(":");
                String name = parts[0];
                int score = Integer.parseInt(parts[1]);
                highScores[i] = new HighScoreEntry(name, score);
                i++;
            }
        } catch (IOException e) {
            System.out.println("An error occurred while reading the high scores file.");
        } finally {
            if (reader != null) {
                reader.close();
            }
        }
    
        return highScores;
    }

    public void updateHighScores(String name, int score) {
        System.out.println("Updating high scores with name " + name + " and score " + score);
        // Write the player's score and name to the high scores file
        writeHighScores(new HighScoreEntry[] {new HighScoreEntry(name, score)});
        
        // Read the high scores from the file
        HighScoreEntry[] highScores = readHighScores();
        
        // Sort the high scores
        sortHighScores(highScores);
    }    

    private void sortHighScores(HighScoreEntry[] highScores) {
        for (int i = 0; i < highScores.length - 1; i++) {
            for (int j = i + 1; j < highScores.length; j++) {
                if (highScores[i].getScore() < highScores[j].getScore()) {
                    HighScoreEntry temp = highScores[i];
                    highScores[i] = highScores[j];
                    highScores[j] = temp;
                }
            }
        }
    }
}

我在游戏class中的调用方式：

HighScore highScore = new HighScore();
highScore.updateHighScores(user, playerPoints);

我只需要使用它们。 除了这些我什么也用不了。

Answer 1

Formatter class 返回格式化的字符串，但您没有捕获format调用的返回值，也没有将结果字符串写入 FileWriter。

它应该看起来像这样：

String result = f.format("%s:%d%n", highScores[i].getName(), highScores[i].getScore());
fw.write(string);

给或换行。