Remove all empty lines

Question

I thought that wasn\'t that hard to do, but I want to remove all empty lines (or lines just containing blanks and tabs in Java) with String.replaceAll.

My regex look

Answer 1

I have some code without using regexp, just import org.apache.commons.lang3.StringUtils;

  File temporaire = new File("temp.txt");
  try {
    Scanner scanner = new Scanner(yourfile);
    BufferedWriter bw = new BufferedWriter(new FileWriter(temporaire));
    while (scanner.hasNextLine()) {
      String line = StringUtils.stripEnd(scanner.nextLine(),null); // Clean blanks at the end of the line
      if (StringUtils.isNotBlank(line)) {
        bw.write(line); // Keep the line only if not blank
        if (scanner.hasNextLine()){
          // Go to next line (Win,Mac,Unix) if there is one
          bw.write(System.getProperty("line.separator"));
        }
      }
      bw.flush();
    }
    scanner.close();
    bw.close();
    fichier.delete();
    temporaire.renameTo(fichier);
  }
  catch (FileNotFoundException e) {
    System.out.println(e.getMessage());
  }
  catch (IOException e) {
    System.out.println(e.getMessage());
  }
}