Where did I go wrong?  should the private variable str be a character,
or should cast?
cast the charAt to a string?

compile code below I get

incomparable types: char and Java.lang.String

class myGen implements Iterator<String>
  {
     private String str;
     private int iToken;

     public myGen(String s)
     {
       str = s.trim();
       iToken= 0;
     }
     public boolean hasNext()
     {
       // I am trying to return true if there is more; otherwise false
       // I am using a while loop to advance iToken until a non-space
is found.
       // I am checking that iToken < str.length() before I test

       while (iToken < str.length()) {
         if (!(str.charAt(iToken) == " " )) {
             return true;  }
         else {
             return false;}
         }
     }
}