replace continuous and repeated pat into single replacement

replace continuous and repeated pattern into a single replacement

 //"Reeeep chineese";  trap if pat == rep

    public static String replaceConsecutiveRepeatedPattern(String str, String pat, String rep) {

        if (pat == null || pat.length() == 0) return str;

        int id = str.indexOf(pat);

        StringBuilder sb = new StringBuilder();

        while (id >= 0) {

            sb.append(str.substring(0, id));

            str = str.substring(id);

            while (str.startsWith(pat, pat.length())) {

               str = str.replaceFirst(pat, "");

            }

            str = str.replaceFirst(pat, rep);

            id = str.indexOf(pat, rep.length());

        }

        sb.append(str);

        return sb.toString();

    }

for example:
with
       str = "Aug  3 23:02:54  2012";
       pat = "&nbsp";
       rep = " ";
replaceConsecutiveRepeatedPattern will change str into
       "Aug 3 23:02:54 2012"