Chatbot method stuck looping in Java

Question

I am coding a simple chatbot, and my method seems to be stuck in a loop. This below is the method, and I suspect there is a problem with the while loop, but I cannot find where I am messing up. No problems with compiling and running other than the stuck loop.

The loop below takes in a complete string, statement, loops for specific keywords, goal, and the starts looking through the string at startPos

private int findKeyword(String statement, String goal, int startPos)
{
  String phrase = statement.trim();
  int psn = phrase.toLowerCase().indexOf(goal.toLowerCase(), startPos);

  while (psn >= 0)
  {
    String before = " ", after = " ";
    if (psn > 0)
    {
      before = phrase.substring(psn-1, psn).toLowerCase();
    }
     if (psn + goal.length() < phrase.length())
    {
      after = phrase.substring(psn + goal.length(), psn + goal.length() + 1).toLowerCase();
    }

    if (((before.compareTo("a") < 0) || (before.compareTo("z") > 0)) && ((after.compareTo("a") < 0) || after.compareTo("z") > 0))
    {
      return psn;
    }

    psn = phrase.indexOf(goal.toLowerCase(), psn + 1);
  }
  return -1;
}

Answer 1

psn = phrase.indexOf(goal.toLowerCase(), psn + 1);

will never rich to (psn < 0) thats the problem