Bug 173836 NPE was thrown when click "Preview " button quickly twice[00]
NPE was thrown when click "Preview " button quickly twice[00] Build number: 2.2.0.v20070212-0630 Steps to reproduce: 1.open attached report 2.click "Preview" button quickly twice Expected result: Report can be previewed properly Actual result: NPE was thrown in second preview Error log: see screen shot
viewer/org.eclipse.birt.report.viewer/birt/WEB-INF/classes/org/eclipse/birt/report/context/ViewerAttributeBean.java
return;
		
		SessionHandle sessionHandle = DesignEngine.newSession( ULocale.US );
		ReportDesignHandle handle = null;
		try
		{
			
			handle = sessionHandle.openDesign( reportConfigName );
			
			if ( handle != null )
			{
				String displayTextParam = null;
				Iterator configVars = handle.configVariablesIterator( );
				while ( configVars != null && configVars.hasNext( ) )
				{
					ConfigVariableHandle configVar = (ConfigVariableHandle) configVars
							.next( );
					if ( configVar != null && configVar.getName( ) != null )
					{
						String paramName = configVar.getName( );
						Object paramValue = configVar.getValue( );
						
						if ( paramName.toLowerCase( ).startsWith(
								ParameterAccessor.PARAM_ISNULL )
								&& paramValue != null )
						{
							String nullParamName = getParameterName(
									(String) paramValue, parameterList );
							if ( nullParamName != null )
								this.configMap.put( nullParamName, null );