Basic String editing with FileWriter

Question

I have 2 Strings that I want to add to a txt File. The first String needs to be in the first Line, the second one in the second line. The "\n" command seems not to work, because in my output file both Strings are in one line.

    FileWriter writer = new FileWriter(measurements);
    String text1 = x.measurementToString(x);
    String text2 = z.measurementToString(z);
    writer.write(text1 + "\n" + text2);
    writer.close();
    System.out.println("Strings added to file!");

suvartheec · Accepted Answer · 2018-01-18T12:22:52.567

1

Since the new line character is different in different OSes, you can use System.getProperty("line.separator") to get newline char for the operating system at runtime.

For Java 7 you can also use System.lineSeparator()

edited Jan 18 '18 at 12:22

answered Jan 18 '18 at 12:14

suvartheec

3,484
1
17
21

Java translates a `\n` automatically to whatever is appropriate for the platform you're on. – SeverityOne Jan 18 '18 at 12:17
@SeverityOne Are you sure about that? hat would really suprise me. If I write a character constant I don't expect Java to mess with that. – Thomas Stets Jan 18 '18 at 12:21
@SeverityOne i dont think it does that and that would be counter-intuitive if that happens. Here is Sir JonSkeet saying i think [the same thing](https://stackoverflow.com/a/3248397/1304575) – suvartheec Jan 18 '18 at 12:26
@SeverityOne No it doesn't. – assylias Jan 18 '18 at 12:35
Thanks, that worked for me. – skonline90 Jan 18 '18 at 13:45

score 0 · Answer 2 · answered Jan 18 '18 at 12:13

Maybe you are on windows and opening the file with a tool that does not recognise \n as a line separator, such as notepad?

File I/O is easier with the methods in the Files class. In your case:

Path p = Paths.get("C:/path/to/your/file/filename.ext");
//or
Path p = measurements.toPath();

Files.write(p, Arrays.asList(text1, text2), StandardCharsets.UTF_8);

This will use the default line separator on your computer and should solve your issue.

score 0 · Answer 3 · answered Jan 18 '18 at 12:14

0

Use PrintWriter.println() instead.

It must be something like that:

try (PrintWriter writer = new PrintWriter(file)) {
    writer.println(text1);
    writer.println(text2);
}

answered Jan 18 '18 at 12:14

D. Braun

508
1
4
11

Basic String editing with FileWriter

3 Answers3