Bug 182670 ScriptedDataSet does not use the same classloader when ran for Parameters than when ran for the report
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/service/ReportEngineService.java
missingParameter = true;
				break;
			}
			if ( IScalarParameterDefn.TYPE_STRING == parameterObj.getDataType( ) )
			{
				String parameterStringValue = (String) parameterValue;
				if ( parameterStringValue != null
						&& parameterStringValue.length( ) <= 0
						&& !parameterObj.allowBlank( ) )
				{
					missingParameter = true;
					break;
				}
			}
		}
		return missingParameter;
	}
	/**
	 * uses to clear the data cach.
	 * 
	 * @param dataSet
	 *            the dataset handle
	 * @throws BirtException
	 */
	public void clearCache( DataSetHandle dataSet ) throws BirtException
	{
		DataSessionContext context = new DataSessionContext(
				DataSessionContext.MODE_DIRECT_PRESENTATION, dataSet
						.getModuleHandle( ), null );
		DataRequestSession requestSession = DataRequestSession