Bug 147819 Dynamic parameter, if value column datas include null datas, preview, system throws exception
Dynamic parameter, if value column datas include null datas, preview, system throws exception Step: data source: sample DB data set: select * from CLASSICMODELS.CUSTOMERS 1.Create a dynamic parameter 2.Display type select List Box, value columm select "State"; display text select "CUSTOMERNAME"; 3.Preview in html Actual Results: 1.System throws Http status 500 exception
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/api/util/ParameterValidationUtil.java
* locale. The value must be the valid data type.
	 * 
	 * @param dataType
	 *            the data type of the input value
	 * @param value
	 *            the input value to validate
	 * @param locale
	 *            the locale information
	 * @return the formatted string
	 * 
	 */
	static private String getDisplayValue( String dataType, Object value,
			ULocale locale )
	{
		if ( DesignChoiceConstants.PARAM_TYPE_DATETIME
				.equalsIgnoreCase( dataType )
				|| value instanceof Date )
		{
			DateFormat formatter = DateFormat.getDateTimeInstance(
					DateFormat.MEDIUM, DateFormat.MEDIUM, locale );
			return formatter.format( (Date) value );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_FLOAT
				.equalsIgnoreCase( dataType )
				|| value instanceof Float || value instanceof Double )
		{
			NumberFormat formatter = NumberFormat.getNumberInstance( locale );
			return formatter.format( ( (Double) value ).doubleValue( ) );
		}
		else if ( DesignChoiceConstants.PARAM_TYPE_DECIMAL