Problem For the users of web reporting tool, when developing web report, they need to configure dataset at first. When data source is complicated, they often want do some special handling to dataset. With the dataset factory listener class of RAQ Report, they can realize this idea. However, users may meet a few problems in the use of dataset factory listener class. Next, we will introduce the common problems to help users to develop web report correctly with RAQ Report. Error information Error code 500 Message: : Failed to generate dataset factory: com.runqian.report4.dataset.SQLDataSetFactory Error source: : In dataset ds1, datasource report/core_epm is setted falsely or not running, please check data source: Abnormity: : Failed to generate dataset factory: com.runqian.report4.dataset.SQLDataSetFactory Error source: : In dataset ds1, datasource report/core_epm is setted falsely or not running, please check data source: at com.runqian.report4.model.CalcReport.calcDataSet(Unknown Source:317) at com.runqian.report4.usermodel.Engine.calc(Unknown Source:96) at ep.verify.expression.VerifyExpression.reportExpressionCalc(VerifyExpression.java:57) at ep.commons.init.InitShowReportParams.verifyReport(InitShowReportParams.java:63) at ep.commons.init.InitShowReportParams.(InitShowReportParams.java:43) at org.apache.jsp.reportJsp.showReport_jsp._jspService(showReport_jsp.java:68) at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:133) at javax.servlet.http.HttpServlet.service(HttpServlet.java:856) Possible Reasons 1. Check the contxet of public void beforeCreated method which is setted to the IDataSetFactoryListener interface. If there is only connection in it, you’d better to set dataset factory. Then, if the connection in context is closed, data can be got from dataset factory. 2. Print connection. If it isn’t empty, the reason may be that datasource is configured repeatedly. If data source information is configured in reportConfig.xml before, users are not allowed to configure it in custom codes again. Or else, it will report error. To solve the problem, users only need to delete those configuration codes. This post is from freezea's blog. You are welcomed cc it anywhere, and please indicate the source. If you would like to read more articles about reporting tool, you are also welcome to refer to my blog.