如何将游戏关卡高分文件按分数从高到低排序并重写

Hey there, let's solve this high score sorting issue step by step. We'll break the problem into three key parts: reading and parsing the score file, sorting the entries, and rewriting the sorted scores back to the original file. Here's a practical, maintainable implementation tailored to your existing code:

1. Create a Score Entry Class #

First, we need a simple class to hold player names and their scores—this makes sorting straightforward:

class ScoreEntry implements Comparable<ScoreEntry> {
    private final String playerName;
    private final int score;

    public ScoreEntry(String playerName, int score) {
        this.playerName = playerName.trim();
        this.score = score;
    }

    // Getters
    public String getPlayerName() {
        return playerName;
    }

    public int getScore() {
        return score;
    }

    // Implement descending sort (highest score first)
    @Override
    public int compareTo(ScoreEntry other) {
        // Reverse the default ascending order for descending sort
        return Integer.compare(other.score, this.score);
        // Optional: Tiebreaker by player name (ascending) if scores are equal
        // if (other.score != this.score) return Integer.compare(other.score, this.score);
        // return this.playerName.compareTo(other.playerName);
    }
}

2. Read and Parse the Score File #

Next, we'll read the level's high score file, skip the header comments, and extract valid score entries:

private List<ScoreEntry> readScores(int levelID) throws IOException {
    List<ScoreEntry> scores = new ArrayList<>();
    File scoreFile = new File("Scoreboard/Level_" + levelID + "_Highscore.txt");

    if (!scoreFile.exists()) {
        return scores; // Return empty list if file doesn't exist yet
    }

    // Use try-with-resources to auto-close the reader
    try (BufferedReader reader = new BufferedReader(new FileReader(scoreFile))) {
        String line;
        while ((line = reader.readLine()) != null) {
            line = line.trim();
            // Skip empty lines and the header comment
            if (line.isEmpty() || line.startsWith("/*")) {
                continue;
            }

            // Parse lines formatted like: "Mathew's score: 540 points;"
            Pattern scorePattern = Pattern.compile("(.*)'s score: (\\d+) points;");
            Matcher matcher = scorePattern.matcher(line);
            if (matcher.matches()) {
                String player = matcher.group(1).trim();
                int score = Integer.parseInt(matcher.group(2));
                scores.add(new ScoreEntry(player, score));
            }
        }
    }
    return scores;
}

3. Sort and Rewrite the File #

Now, we'll sort the parsed scores and overwrite the original file with the sorted entries:

public void sortAndRewriteHighscores(int levelID) throws IOException {
    List<ScoreEntry> sortedScores = readScores(levelID);
    Collections.sort(sortedScores); // Uses our custom compareTo for descending order

    // Overwrite the original file
    File scoreFile = new File("Scoreboard/Level_" + levelID + "_Highscore.txt");
    try (FileWriter writer = new FileWriter(scoreFile, false)) {
        // Write the header comment first
        writer.write("/*---Highscores---*/ \n \n");
        // Write each sorted score entry
        for (ScoreEntry entry : sortedScores) {
            writer.write(String.format("%s's score: %d points;\n",
                    entry.getPlayerName(), entry.getScore()));
        }
    }
}

4. Integrate with Your Existing scoreWrite Method #

To make sorting automatic every time a new score is added, call the sort method at the end of your scoreWrite function:

public void scoreWrite(int levelID) throws IOException {
    File highscores = new File("Scoreboard/Level_" + levelID + "_Highscore.txt");
    if (highscores.createNewFile()) {
        try (FileWriter writer = new FileWriter(highscores, false)) {
            writer.write("/*---Highscores---*/ \n \n");
            writer.write(SokobanGame.getInstance().getPlayerName() + "'s score: " + getScore() + " points;\n");
        }
    } else {
        try (FileWriter writer = new FileWriter(highscores, true)) {
            writer.write(SokobanGame.getInstance().getPlayerName() + "'s score: " + getScore() + " points;\n");
        }
    }
    // Auto-sort after adding a new score
    sortAndRewriteHighscores(levelID);
}

Quick Notes #

• Duplicate Players: If you want to keep only the highest score per player, add a check when reading entries (e.g., use a Map<String, Integer> to track the highest score for each player, then convert to a list).
• File Permissions: Make sure your app has read/write access to the Scoreboard directory—if it doesn't exist, add code to create it with new File("Scoreboard").mkdirs(); before writing files.
• Alternative Format: If your file uses the space-separated format from your example (/*Scores*/ Mathew: 540 Stacy: 070...), adjust the parsing logic to split the line after the comment, then iterate over name-score pairs.

内容的提问来源于stack exchange，提问作者Coder101