bufferedwriter doesn't write first line

Frage zur Aufgabe

Gelöst

Hello, I was able to solve this task, but still have a few questions. 1. I don't understand, why bufferedwriter doesn't write first line. Input is: 1 2 3 exit In my file I can find: 2 3 exit 2. Where shoud I close the reader? Can anybody please help me? Thank you :)

BufferedReader reader = null;
BufferedWriter bufferedWriter = null;
FileWriter fileWriter = null;

try {
    reader = new BufferedReader(new InputStreamReader(System.in));
    String datei = reader.readLine();

    fileWriter = new FileWriter(datei);
    bufferedWriter = new BufferedWriter(fileWriter);

    while (true) {

        String zahl = reader.readLine();

        bufferedWriter.write(zahl);
        bufferedWriter.newLine();

        if (zahl.equals("exit")) {
           // reader.close();
            break;
        }
    }

} catch (IOException e) {
    e.printStackTrace();
} finally {

    bufferedWriter.close();
    fileWriter.close();
}

Kommentare (3)

Beliebt
Neu
Alt

Du musst angemeldet sein, um einen Kommentar schreiben zu können

Guadalupe Gagnon

Level 37 , Tampa, United States

1 Februar 2021, 17:58

Lösung

#1 did you first enter the file name? The input order should be: {filename} 1 2 3 exit When i ran your code the file had: 1 2 3 exit in it as was entered. #2 you should always close a stream as soon as you are done using it. Both of the streams in this code for input and output are done when "exit" is entered. In the finally block is a perfect place in this code for them to be closed because this is the next place that the code would process when line 21 is reached.

Guadalupe Gagnon

Level 37 , Tampa, United States

1 Februar 2021, 18:03

if you did not enter a file name then you are going to have a file named '1' in your CodeGymTasks main folder:

Sylwia

Level 16 , Deutschland , Germany

1 Februar 2021, 18:59

Thank you Guandalupe :) I changed my code and it works :)

BufferedReader reader = null;
BufferedWriter bufferedWriter = null;
FileWriter fileWriter = null;

reader = new BufferedReader(new InputStreamReader(System.in));
fileWriter = new FileWriter(reader.readLine());
bufferedWriter = new BufferedWriter(fileWriter);

try {
    while (true) {

        String zahl = reader.readLine();

        bufferedWriter.write(zahl);
        bufferedWriter.newLine();

        if (zahl.equals("exit")) {
            break;
        }
    }
} catch (IOException e) {
    e.printStackTrace();
} finally {
    reader.close();
    bufferedWriter.close();
    fileWriter.close();
}