public static String fullWidthToHalfWidth(String s){
  if (isEmpty(s)) {
    return s;
  }
  char[] source=s.toCharArray();
  for (int i=0; i < source.length; i++) {
    if (source[i] == 12288) {
      source[i]=' ';
    }
 else     if (source[i] >= 65281 && source[i] <= 65374) {
      source[i]=(char)(source[i] - 65248);
    }
 else {
      source[i]=source[i];
    }
  }
  return new String(source);
}

public static String fullWidthToHalfWidth ( String s ) { if ( isEmpty ( s ) ) { return s ; } char [ ] source = s . toCharArray ( ) ; for ( int i = 0 ; i < source . length ; i ++ ) { if ( source [ i ] == 12288 ) { source [ i ] = ' ' ; } else if ( source [ i ] >= 65281 && source [ i ] <= 65374 ) { source [ i ] = ( char ) ( source [ i ] - 65248 ) ; } else { source [ i ] = source [ i ] ; } } return new String ( source ) ; }
transform half width char to full width char
