* @return the parameter value as a String, or defaultValue if not found
     */
    public String getAsString(final String key, final String defaultValue) {
        final String value = getAsString(key);
        if (value != null) {
            return value;
        }
        return defaultValue;
    }

    /**

        final java.sql.Timestamp result = (java.sql.Timestamp) converter.getAsObject("2008/12/31 12:34:56");
        System.out.println(result);
        assertThat(converter.getAsString(result), is("2008/12/31 12:34:56"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIsTarget() throws Exception {

        final java.sql.Date result = (java.sql.Date) converter.getAsObject("2008/01/16");
        System.out.println(result);
        assertThat(converter.getAsString(result), is("2008/01/16"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIsTarget() throws Exception {

            defaultDataMap.put(fessConfig.getIndexFieldExpires(), documentExpires);
        }
        // segment
        defaultDataMap.put(fessConfig.getIndexFieldSegment(), initParamMap.getAsString(Constants.SESSION_ID));
        // created
        defaultDataMap.put(fessConfig.getIndexFieldCreated(), systemHelper.getCurrentTime());
        // boost

    }

    /**
     * @throws Exception
     */
    @Test
    public void testGetAsString() throws Exception {
        final NumberConverter converter = new NumberConverter("##0");
        assertThat(converter.getAsString(Integer.valueOf("100")), is("100"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIsTarget() throws Exception {

 */
public interface Converter {

    /**
     * Returns the value as a string.
     *
     * @param value
     *            the value
     * @return the value as a string
     */
    String getAsString(Object value);

    /**
     * Returns the value as an object.
     *
     * @param value
     *            the value
     * @return the value as an object
     */
    Object getAsObject(String value);

        if (StringUtil.isEmpty(value)) {
            return null;
        }
        return DateConversionUtil.toSqlDate(value, pattern);
    }

    @Override
    public String getAsString(final Object value) {
        if (value == null) {
            return null;
        }
        return StringConversionUtil.toString((Date) value, pattern);
    }

    @Override

        final DateConverter converter = new DateConverter("yyyy/MM/dd");
        final Date result = (Date) converter.getAsObject("2008/01/16");
        System.out.println(result);
        assertThat(converter.getAsString(result), is("2008/01/16"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testIsTarget() throws Exception {
        final DateConverter converter = new DateConverter("yyyy/MM/dd");

        final TimeConverter converter = new TimeConverter("HH:mm:ss");
        final java.sql.Time result = (java.sql.Time) converter.getAsObject("12:34:56");
        System.out.println(result);
        assertThat(converter.getAsString(result), is("12:34:56"));
    }

    /**
     * @throws Exception
     */
    public void testIsTarget() throws Exception {
        final TimeConverter converter = new TimeConverter("yyyy/MM/dd");

            return new DecimalFormat(pattern).parse(value);
        } catch (final ParseException e) {
            throw new ParseRuntimeException(e);
        }

    }

    @Override
    public String getAsString(final Object value) {
        if (value == null) {
            return null;
        }
        return new DecimalFormat(pattern).format(value);
    }

    @Override