Find and replace all NewLine or BreakLine characters with \n in a String - Platform independent

Question

I am looking for a proper and robust way to find and replace all newline or breakline chars from a String independent of any OS platfo

Answer 1

This seems to work well:

String s = "This is a String\nand all newline chars\nshould be replaced in this example.";
System.out.println(s);
System.out.println(s.replaceAll("[\\n\\r]+", "\\\\n"));

By the way, you don't need to catch exception.

Answer 2

If you want literal \n then following should work:

String repl = str.replaceAll("(\\r|\\n|\\r\\n)+", "\\\\n")

Answer 3

Oh sure, you could do it with one line of regex, but what fun is that?

public static String fixToNewline(String orig){
    char[] chars = orig.toCharArray();
    StringBuilder sb = new StringBuilder(100);
    for(char c : chars){
        switch(c){
            case '\r':
            case '\f':
                break;
            case '\n':
                sb.append("\\n");
                break;
            default:
                sb.append(c);
        }
    }
    return sb.toString();
}

public static void main(String[] args){
   String s = "This is \r\n a String with \n Different Newlines \f and other things.";

   System.out.println(s);
   System.out.println();
   System.out.println("Now calling fixToNewline....");
   System.out.println(fixToNewline(s));

}

The result

This is 
 a String with 
 Different Newlines  and other things.

Now calling fixToNewline....
This is \n a String with \n Different Newlines  and other things.