Почему выводит много пробелов?

public class Solution {


    public static void main(String[] args) {
        try (BufferedReader reader = new BufferedReader(new InputStreamReader(System.in))) {
            String file1 = reader.readLine();
            String file2 = reader.readLine();
            String ch = null;

            BufferedReader reader1 = new BufferedReader(new FileReader(file1));
            BufferedWriter writer2 = new BufferedWriter(new FileWriter(file2));

            while ((ch = reader1.readLine()) != null) {   //ложим в ch всю линию
                Pattern p = Pattern.compile("\\b\\d*\\b");
                Matcher m = p.matcher(ch);
                while(m.find()) {
                    writer2.write(m.group());
                    writer2.write(" ");
                }
            }
            reader1.close();
            writer2.close();
        }catch (IOException ex) {}
    }
}