java - 如何编码以便我不会添加重复记录而不是覆盖 txt 文件中的内容

Question

import java.io.*;

public class SaveGame {

    public static void main(String[] args) {
        String user = "John";//rewrite as String user = String.toString(Game.user)
        String compTime1 = "2";
        String compTime2 = "0";
        String compTime3 = "0";
        String compLevel = "2";
        String tokenCollected = "3";
        String flipperCollected = "2";
        String firebootsCollected = "4";
        String wingbootsCollected = "3";
        String keysCollected = "3";

        saveGame(user,compTime1,compTime2,compTime3,compLevel, tokenCollected, flipperCollected,firebootsCollected,wingbootsCollected,keysCollected);
    }

    public static void saveGame(String user, String compTime1, String compTime2, String compTime3, String compLevel, String tokenCollected, String flipperCollected, String firebootsCollected, String wingbootsCollected, String keysCollected) {
        try
        {
            FileWriter fw = new FileWriter("Game.txt",true);
            BufferedWriter bw = new BufferedWriter(fw);
            PrintWriter pw = new PrintWriter(bw);

            pw.print("\n" +user + "," + compTime1 + "," + compTime2 + "," + compTime3 + "," + compLevel + "," + tokenCollected + "," + flipperCollected + "," + firebootsCollected + "," + wingbootsCollected + "," + keysCollected);
            pw.flush();
            pw.close();
        } catch(Exception e) {
            e.printStackTrace();
            System.out.println("Record not saved"); 
        }   
    }
}

我应该写什么，以便当我添加名称为 John 的数据时，该数据已存在于 game.txt 文件中，不会再次添加，而是会覆盖其中包含 John 的记录在 game.txt 中。我发现只有添加有效。

Answer 1

如果文件不大，您可以将整个文件读取到内存中。将读取的字符串数据解析为对象列表或映射。然后应用新的更改并将整个 block 重新写入文件。您可以将对象的 map 或列表传递给写入函数。