Bug 207250 Check blank value for datetime type parameter from url.[0002][0705]
Description: Check blank value for datetime type parameter from url. Build number:2.3.0.v20071023 Steps to reproduce: 1. New a datetime parameter mydt,listbox, tick off isRequired. 2. Preview in external browser and add "&dt=" in url, press enter. Expected result: Error message to indicate blank value isn't allowed for this parameter. Actual result: No error message and blank value is accepted. I tried to new a jsp and use <birt:paramDef> to pass the blank value and the blank value is accepted,too. Error log:n/a
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
* @return Map
	 */
	protected Map getParsedParametersAsString( Collection parameterList,
			HttpServletRequest request, InputOptions options )
			throws ReportServiceException
	{
		Map params = new HashMap( );
		if ( parameterList == null )
			return params;
		for ( Iterator iter = parameterList.iterator( ); iter.hasNext( ); )
		{
			ParameterDefinition parameter = (ParameterDefinition) iter.next( );
			if ( parameter == null )
				continue;
			
			String paramName = parameter.getName( );
			if ( paramName == null )
				continue;
			
			String paramValue = null;
			if ( ParameterAccessor.isReportParameterExist( request, paramName ) )
			{
				if ( parameter.isMultiValue( ) )
				{
					
					List values = ParameterAccessor.getReportParameters(
							request, paramName );
					params.put( paramName, values );
				}
				else