com.aspose.words

Example:

public void insertCustomFormattingField() throws Exception
{
    Document doc = new Document();
    DocumentBuilder builder = new DocumentBuilder(doc);

    Field field = builder.insertField("=-1234567.89 \\# \"### ### ###.000\"", null);
    doc.getFieldOptions().setResultFormatter(new FieldResultFormatter("[{0}]", null));

    field.update();

}

private class FieldResultFormatter implements IFieldResultFormatter
{
    FieldResultFormatter(String numberFormat, String dateFormat)
    {
        mNumberFormat = numberFormat;
        mDateFormat = dateFormat;
    }

    public String formatNumeric(double value, String format)
    {
        mNumberFormatInvocations.add(new Object[]{value, format});

        return (mNumberFormat == null || "".equals(mNumberFormat)) ? null : MessageFormat.format(mNumberFormat, value);
    }

    public String formatDateTime(Date value, String format, /*CalendarType*/int calendarType)
    {
        mDateFormatInvocations.add(new Object[]{value, format, calendarType});

        return (mDateFormat == null || "".equals(mDateFormat)) ? null : MessageFormat.format(mDateFormat, value);
    }

    public String format(String value, /*GeneralFormat*/int format)
    {
        throw new UnsupportedOperationException();
    }

    public String format(double value, /*GeneralFormat*/int format)
    {
        throw new UnsupportedOperationException();
    }

    private /*final*/ String mNumberFormat;
    private /*final*/ String mDateFormat;

    private /*final*/ ArrayList mNumberFormatInvocations = new ArrayList();
    private /*final*/ ArrayList mDateFormatInvocations = new ArrayList();
    private IFieldResultFormatter fieldResultFormatterImplementation;
}