Indexes of indexOf

Have you ever come across a situation in which you want to gather a list of indexes of the one particular substring in a string but you are limited to using only indexOf() method? I did and I wrote this method to ease my work in the future in the event that I need to get the list of indexes of the given substring. The code is as follow.

public static ArrayList indices(String inputString, String sampleString){
  int length = inputString.length();
  int inputStringIndex = -1;
  StringBuffer newString = new StringBuffer(); 
  int index = 0;  
  int check = 0;
  ArrayList compile = new ArrayList();
  while (index < length) {
    try {
      if (inputString.charAt(index) == sampleString.charAt(check)) {
        newString.append(inputString.charAt(index));
        check++;
        if (newString.toString().equals(sampleString)) {
          inputStringIndex = (index - check) + 1 ;
          compile.add(inputStringIndex);
          newString.setLength(0);
        }
      }
      if (check == (sampleString.length())) {
        check = 0;
      }
    } catch (Exception ex){}
    index++;
  }  
  if (compile.size() == 0) {
    compile.add(inputStringIndex);
  }  
  return compile;
}

The usage of this static method is very simple and trivial. Given a string "Nicholas Key Key Key Nicholas Key" and a sample substring "Key", you will get the result of [9, 13, 17, 30].