Posible duplicado:
¿Cómo puede un programa Java usar archivos dentro de .jar para leer y escribir?

¿Cómo escribo en un archivo .txt desde unTARRO java compilado proyecto?

Cuando ejecuto mis proyectos, no da errores, pero simplemente no escribe en el .txt dentro del archivo JAR.

Hago el archivo JAR usando:

netbeans clean /build tool

Código:

public class FileIO   {
    private File file;
    private Scanner filescScanner, lineScanner;
    private PrintWriter fileWriter;
    private String[][] data;

    public FileIO () {
        data = new String[100][2];
    }

    public String[][] getLineScores(){
        return this.loadHighscores(this.getClass().getResourceAsStream("LineHighscores.txt"));
    }

    public String[][] getTimeScores(){
        return this.loadHighscores(this.getClass().getResourceAsStream("TimeHighscores.txt"));
    }

    public void setLineScores( String name,String lines ){
        boolean found= false;
        data = this.getLineScores();
        for(int i = 0; i<data.length && !found ; i++){
            if(data[i][0] == null || "Niemand".equals(data[i][0])){
                data[i][0]=name;
                data[i][1]=lines;
                found=true;
            }
        }
        this.saveHighscores(this.getClass().getResource("LineHighscores.txt"),data);
    }

    public void setTimeScores(String time, String name){
        boolean found= false;
        data = this.getLineScores();
        for(int i = 0; i<data.length && !found ; i++){
            if(data[i][0] == null || "Niemand".equals(data[i][0])){
                data[i][0]=name;
                data[i][1]=time;
                found=true;
            }

        }
        this.saveHighscores(this.getClass().getResource("TimeHighscores.txt"),data);
    }

    private String[][] loadHighscores( InputStream resourceStream){
        int x=0;
        String test = "";
        try{
            filescScanner = new Scanner(resourceStream);
        }
        catch(Exception ioe){
            System.err.println(ioe);
        }

        if (filescScanner.hasNext()){
            while(filescScanner.hasNextLine()&& x<100) {
                lineScanner = new Scanner(filescScanner.nextLine());
                lineScanner.useDelimiter("-/-");

                data[x][0]=lineScanner.next();//name
                data[x][1]=lineScanner.next();//data
                x++;
            }
            lineScanner.close();
            filescScanner.close();
        }
        else{
            data[0][0] = "Niemand";
            data[0][1] = "0";
        }
        return data;
    }

    private void saveHighscores( URL resourceStream, String[][] data){
        int x=0;
        try {
            file = new File(resourceStream.toURI());
        } catch (URISyntaxException ex) {
            Logger.getLogger(FileIO.class.getName()).log(Level.SEVERE, null, ex);
        }

        try {
            fileWriter = new PrintWriter(file);
        } catch (FileNotFoundException ex) {
            Logger.getLogger(FileIO.class.getName()).log(Level.SEVERE, null, ex);
        }
        if(data.length>x){
            while(data.length>x && data[x][0] != null ){
                fileWriter.println(data[x][0]+"-/-"+data[x][1]);
                x++;
            }
            fileWriter.close();
        }
    }

    public static void main(String[] args){
        FileIO file = new FileIO();
        file.setLineScores("55555555", "KoenKevin");
    }
}