Bug 214204 Only document content in document folder should be removed.[0601]
Description: Only document related content in document folder should be removed. Build number:2.3.0.v20080103 Steps to reproduce: 1. Deploy BIRT. 2. Edit web.xml to set BIRT_VIEWER_DOCUMENT_FOLDER to your local path and there are content inside the path. 3. Start server and click View Example to preview sample report. Expected result: Only content created by viewer should be removed in specified document folder. Actual result: All contents are deleted despite whether they are related with BIRT. Error log:n/a
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/utility/ParameterAccessor.java
if ( paramMap == null || !paramMap.containsKey( ISOName ) )
		{
			value = defaultValue;
		}
		Set nullParams = getParameterValues( request, PARAM_ISNULL );
		if ( nullParams != null && nullParams.contains( name ) )
		{
			value = null;
		}
		return value;
	}
	/**
	 * Get report parameters by given name, support multi-value parameter.
	 * 
	 * @param request
	 *            http request
	 * @param paramName
	 *            parameter name
	 * @return parameter value
	 */
	public static List getReportParameters( HttpServletRequest request,
			String paramName )
	{
		assert request != null && paramName != null;
		List paramList = new ArrayList( );
		Set params = getParameterValues( request, paramName );
		if ( params != null )
		{
			Iterator it = params.iterator( );
			while ( it.hasNext( ) )