code: public void applyPattern(String primaryPattern, String[] alternativePatterns, char decimalSeparator, char groupingSeparator)
     {
        m_symbols.setDecimalSeparator(decimalSeparator);
        m_symbols.setGroupingSeparator(groupingSeparator);
  
        setDecimalFormatSymbols(m_symbols);
        applyPattern(primaryPattern);
  
        if (alternativePatterns != null && alternativePatterns.length != 0)
        {
           int loop;
           if (m_alternativeFormats == null || m_alternativeFormats.length != alternativePatterns.length)
           {
              m_alternativeFormats = new DecimalFormat[alternativePatterns.length];
              for (loop = 0; loop < alternativePatterns.length; loop++)
              {
                 m_alternativeFormats[loop] = new DecimalFormat();
              }
           }
  
           for (loop = 0; loop < alternativePatterns.length; loop++)
           {
              m_alternativeFormats[loop].setDecimalFormatSymbols(m_symbols);
              m_alternativeFormats[loop].applyPattern(alternativePatterns[loop]);
           }
        }
     }
docs: This method is used to configure the primary and alternative
  format patterns.
  
  @param primaryPattern new format pattern
  @param alternativePatterns alternative format patterns
  @param decimalSeparator Locale specific decimal separator to replace placeholder
  @param groupingSeparator Locale specific grouping separator to replace placeholder