In javascript the type for numbers can be different from the format type - * specifier. For format type '%d', '%o', '%x', '%X' double need to be - * converted to integer. For format type 'e', 'E', 'f', 'g', 'G', 'a', 'A' - * integer needs to be converted to double. - * - *
Format type "%c" and javascript string needs special handling. - * - *
The javascript date objects can be handled if they are type double (the - * related javascript code will convert with Date.getTime() to double). So - * double date types are converted to long. - * - *
Pattern and the logic for parameter position: java.util.Formatter - * - */ -final class Formatter { - - private Formatter() { - } - - /** - * Method which converts javascript types to java types for the - * String.format method (jrunscript function sprintf). - * - * @param format a format string - * @param args arguments referenced by the format specifiers in format - * @return a formatted string - */ - static String format(final String format, final Object[] args) { - final Matcher m = FS_PATTERN.matcher(format); - int positionalParameter = 1; - - while (m.find()) { - int index = index(m.group(1)); - final boolean previous = isPreviousArgument(m.group(2)); - final char conversion = m.group(6).charAt(0); - - // skip over some formats - if (index < 0 || previous - || conversion == 'n' || conversion == '%') { - continue; - } - - // index 0 here means take a positional parameter - if (index == 0) { - index = positionalParameter++; - } - - // out of index, String.format will handle - if (index > args.length) { - continue; - } - - // current argument - final Object arg = args[index - 1]; - - // for date we convert double to long - if (m.group(5) != null) { - // convert double to long - if (arg instanceof Double) { - args[index - 1] = ((Double) arg).longValue(); - } - } else { - // we have to convert some types - switch (conversion) { - case 'd': - case 'o': - case 'x': - case 'X': - if (arg instanceof Double) { - // convert double to long - args[index - 1] = ((Double) arg).longValue(); - } else if (arg instanceof String - && ((String) arg).length() > 0) { - // convert string (first character) to int - args[index - 1] = (int) ((String) arg).charAt(0); - } - break; - case 'e': - case 'E': - case 'f': - case 'g': - case 'G': - case 'a': - case 'A': - if (arg instanceof Integer) { - // convert integer to double - args[index - 1] = ((Integer) arg).doubleValue(); - } - break; - case 'c': - if (arg instanceof Double) { - // convert double to integer - args[index - 1] = ((Double) arg).intValue(); - } else if (arg instanceof String - && ((String) arg).length() > 0) { - // get the first character from string - args[index - 1] = (int) ((String) arg).charAt(0); - } - break; - default: - break; - } - } - } - - return String.format(format, args); - } - - /** - * Method to parse the integer of the argument index. - * - * @param s string to parse - * @return -1 if parsing failed, 0 if string is null, > 0 integer - */ - private static int index(final String s) { - int index = -1; - - if (s != null) { - try { - index = Integer.parseInt(s.substring(0, s.length() - 1)); - } catch (final NumberFormatException e) { - //ignored - } - } else { - index = 0; - } - - return index; - } - - /** - * Method to check if a string contains '<'. This is used to find out if - * previous parameter is used. - * - * @param s string to check - * @return true if '<' is in the string, else false - */ - private static boolean isPreviousArgument(final String s) { - return (s != null && s.indexOf('<') >= 0); - } - - // %[argument_index$][flags][width][.precision][t]conversion - private static final String formatSpecifier = - "%(\\d+\\$)?([-#+ 0,(\\<]*)?(\\d+)?(\\.\\d+)?([tT])?([a-zA-Z%])"; - // compiled format string - private static final Pattern FS_PATTERN; - - static { - FS_PATTERN = Pattern.compile(formatSpecifier); - } -}