public static String toLowerString(String s){
  int len=s.length();
  int idx=0;
  for (; idx < len; idx++) {
    if (isUpper(s.charAt(idx))) {
      break;
    }
  }
  if (idx == len) {
    return s;
  }
  char[] buf=new char[len];
  for (int i=0; i < len; i++) {
    char c=s.charAt(i);
    buf[i]=(i < idx) ? c : toLower(c);
  }
  return new String(buf);
}

public static String toLowerString ( String s ) { int len = s . length ( ) ; int idx = 0 ; for ( ; idx < len ; idx ++ ) { if ( isUpper ( s . charAt ( idx ) ) ) { break ; } } if ( idx == len ) { return s ; } char [ ] buf = new char [ len ] ; for ( int i = 0 ; i < len ; i ++ ) { char c = s . charAt ( i ) ; buf [ i ] = ( i < idx ) ? c : toLower ( c ) ; } return new String ( buf ) ; }
converts the given ascii string to lower - case .
