Replacing Substrings in a String

 static String replace(
   String str, String pattern, String replace) {
     int s = 0;
     int e = 0;
     StringBuffer result = new StringBuffer();
     
     while ((e = str.indexOf(pattern, s)) >= 0) {
       result.append(str.substring(s, e));
       result.append(replace);
       s = e+pattern.length();
     }
     result.append(str.substring(s));
     return result.toString();
 }