How to split a string by every other separator

Question

There's a string

String str = "ggg;ggg;nnn;nnn;aaa;aaa;xxx;xxx;";

How do I split it into strings like this "ggg;ggg;" "nnn;nnn;" "aaa;aaa;" "xxx;xxx;" ???????

Answer 1

Using Regex

    String input = "ggg;ggg;nnn;nnn;aaa;aaa;xxx;xxx;";
    Pattern p = Pattern.compile("([a-z]{3});\\1;");
    Matcher m = p.matcher(input);
    while (m.find())
        // m.group(0) is the result
        System.out.println(m.group(0));

Will output

ggg;ggg;

nnn;nnn;

aaa;aaa;

xxx;xxx;

Answer 2

I assume that the you only want to check if the last segment is similar and not every segment that has been read.

If that is not the case then you would probably have to use an ArrayList instead of a Stack.

I also assumed that each segment has the format /([a-z])\1\1/.

If that is not the case either then you should change the if statement with:

(stack.peek().substring(0,index).equals(temp))

public static Stack<String> splitString(String text, char split) {
    Stack<String> stack = new Stack<String>();
    int index = text.indexOf(split);
    while (index != -1) {
        String temp = text.substring(0, index);
        if (!stack.isEmpty()) {
            if (stack.peek().charAt(0) == temp.charAt(0)) {
                temp = stack.pop() + split + temp;
            }
        }
        stack.push(temp);
        text = text.substring(index + 1);
        index = text.indexOf(split);
    }
    return stack;
}