java string delimiter, keeping delimiter in token

Question

im trying to split a string but keep the delimiter at the beginning of the next token (if thats possible)

Example: I\'m trying to split the string F120LF120L

Answer 1

How about doing it brute force?

String del = "L";
String str = "F120LLF120LLLLF12L";
int i = 0;

while (true) {
    i = str.indexOf(del, i);
    if (i == -1) break;
    String a = str.substring(0, i);
    String b = str.substring(i + del.length());
    str = a + " " + del;
    str += b.startsWith(del) || b.length() == 0 ? b : " " + b;
    i = a.length() + del.length() + 1;
}

System.out.println(str);
// Will print: F120 L L F120 L L L L F12 L

Answer 2

Use split(), for all practical purposes StringTokenizer is deprecated (it's still there only for backwards compatibility). This will work:

String delimiter = "L";
String str = "F120LF120L";
String[] splitted = str.split(delimiter);

for (String s : splitted) {
    System.out.println(s);
    System.out.println(delimiter);
}

> F120
> L
> F120
> L

Answer 3

From the docs, you can use StringTokenizer st = new StringTokenizer(str, "L", true); The last parameter is a boolean that specifies that delimiters have to be returned too.