Remove blank lines in StringBuffer

Question

After reading text file that contain words and numbers, I split it into words and numbers and left with blank lines in both splited words and numbers.

I try to remove the blank lines but the code did'nt work. Someone can help

 String textfile = read.next();

 String[] words = textfile.split("\\d");
 String[] numbers = textfile.split("[^0-9]");

 StringBuffer splitedwords = new  StringBuffer();

 StringBuffer splitednumbers = new StringBuffer();

  for(int k = 0; k<numbers.length; k++ )

  {

    splitednumbers.append(numbers[k]);

 String remove_blank_lines_of_splitednumbers = splitednumbers.toString();


   remove_blank_lines_of_splitednumbers.replaceAll("[\r\n]{2,}",  "");

 System.out.println(remove_blank_lines_of_splitednumbers);

  }

Igot this output

13
46
16

   

   


 08
 96
 11






 150
 200
 379

I want the output to be

 13
 46 
 16
  08
  96
  11
  150
  200
  379

Answer 1

If you need to remove white spaces, such as your empty lines, at the beginning or end of a String you can simply use the trim method instead of restorting to a replace with a regex.

If you'll aplly a trim on each numbers[k] in your for you should be able to remove every white characters around them.

splitednumbers.append(numbers[k].trim());

Or try still the replaceAll withe a regex matching white spaces.

splitednumbers.append(numbers[k].replaceAll("\\s+", ""));

Answer 2

Maybe you should still try with a replaceAll but using the \s character class though. I don't think this code (replaceAll("[\r\n]{2,}", ""); can detect you new lines and carriage return the way you expect.