string replace algorithm

gistfile1.java

public String replace(String original, String toReplace, String replaceWith) {
  char[] origArray = original.toCharArray();
  char[] toReplaceArray = toReplace.toCharArray();
  StringBuilder result = new StringBuilder();
        
  int index = 0;
  while(index < origArray.length){
    if(isPotentialMatch(origArray[index], toReplaceArray[index])){
      if(isMatch(index, origArray, toReplaceArray)){
        result.append(replaceWith);
        index += toReplace.length() - 1;
      }
      } else {
        result.append(origArray[index]);
      }
    index++;
  }
  return result.toString();
}

private boolean isPotentialMatch(char a, char b) {
  return a == b;
}

private boolean isMatch(Integer index, char[] original, char[] toReplace) {
  for(int i = index; i < toReplace.length; i++){
    if(original[i] != toReplace[i]){
      return false;
    }
  }
  return true;
}