替换Java中文本文件的内容

Question

I have a text file named leaderboard.txt, I load it up as a resource stream and read the contents to a string (it's a short text file) then I replace something in the string after that I want to create a new leaderboard.txt file in the same location or overwrite the previous leaderboard.txt text file.

Here is my code for overwriting the file, but it throws a java.lang.NullPointerException

package tools;
import java.io.BufferedReader;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.PrintWriter;

import screens.PlayMenu;


public class Leaderboard
{
    private static BufferedReader leaderboardIn;

    public static void checkLeaderBoard(int time, int currentLevel)
    {
        try
        {
            InputStream filePath = Leaderboard.class
                    .getResourceAsStream("/Other/Leaderboard.txt");
            leaderboardIn = new BufferedReader(new InputStreamReader(filePath));

            String input = "";
            for (int level = 1; level < currentLevel; level++)
                input = leaderboardIn.readLine() + '\n';
            String line = leaderboardIn.readLine();
            int leaderboardTime = Integer.parseInt(line.substring(0,
                    line.indexOf(' ')));
            if (leaderboardTime > time)
            {
                line = time + " " + PlayMenu.playerName.toUpperCase() + '\n';
                input += line;
                while ((line = leaderboardIn.readLine()) != null)
                    input += line + '\n';
                 PrintWriter fileOut = 
                           new PrintWriter(
                                 new File(Leaderboard.class.getResource("/Trial and Error/resources/Other/Leaderboard.txt").getPath()));
                fileOut.write(input);
                fileOut.close();
            }
            filePath.close();
            leaderboardIn.close();
        }
        catch (IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}

Here's a picture of where my actual text file is:

Any kind of help would be appreciated.

Edit Here's the stack trace (which is also in the image)

Exception in thread "Thread-0" java.lang.NullPointerException
at tools.Leaderboard.checkLeaderBoard(Leaderboard.java:39)
at entities.Player.onExit(Player.java:91)
at entities.Player.update(Player.java:38)
at screens.GameState.update(GameState.java:27)
at main.Game.update(Game.java:62)
at main.Game.run(Game.java:111)
at java.lang.Thread.run(Unknown Source)

Answer 1

I would have posted this as a comment, but apparently I don't have enough reputation to do that, so...

Why not just use Files.readAllLines() and Files.write() ?

Answer 2

As I can see stack trace, which is pointing at Line 39 Please write following code and see their output.

Leaderboard c = new Leaderboard();
Class cls = c.getClass();

// finds resource relative to the class location
URL url = cls.getResource("/Other/Leaderboard.txt");
System.out.println("Value = " + url);

// finds resource relative to the class location
url = cls.getResource("/Trial and Error/resources/Other/Leaderboard.txt");
System.out.println("Value = " + url);

If last one returns null , then resource with the name is not found.

Additionally, Try following

Leaderboard c = new Leaderboard();
    Class cls = c.getClass();
fileOut = new PrintWriter(new File(cls.getResource("/Other/Leaderboard.txt").getPath()));

instead of

 PrintWriter fileOut = new PrintWriter(new File(Leaderboard.class.getResource("/Trial and Error/resources/Other/Leaderboard.txt").getPath()));