如何在Java中附加文件

Question

如何將highscore按降序附加到highscore.txt文件中的正確位置？ 該方法使用之前創建的readHighScore（int score）方法來查找應在其中插入記錄的行號。 這是我到目前為止所得到的：

public static void recordHighScore(String name, int score){
            File file = new File("Test/highscore.txt");
            FileWriter fwriter = new FileWriter(file, true);
            try{
                String userName = name+","+score;
                fwriter.add(readHighScore(score), userName);

            }catch(IOException io){
                System.out.println("Missing File!");

            }

            /*Writes the high score into highscore.txt file, at the correct position (in descending order). This
            method uses readHighScore( ) method to find the line number where the record should be
            inserted.*/
        }

Answer 1

如果要在末尾附加數據非常容易，而如果要在中間附加數據幾乎是不可能的。 輕松讀取內存中的所有文件，進行更改並再次保存所有文件，覆蓋舊的信息非常容易。

例如：

// read file to arraylist
Scanner s = new Scanner(new File("filepath"));
List<Score> list = new ArrayList<Score>();
while (s.hasNext()){
    String[] a = s.next().split(","); 
    list.add(new Score(a[0], a[1]); ); // Score is class with name and score fields
}
s.close();

// working with List<Score>
// add new score to List<Score>
// save List<Score> to file like in your code