Pros & cons - query in report template & beans

[peterramesh]

Hi all,

 

I'm a newbie to JasperReports, in our application we are using JasperReports 1.3.4, Hibenate 3.1 and Spring 2.0.2.

 

Basically, I like to know the pros and cons of having query in report template and beans.

 

I ran some tests by referring the JasperReport samples.

 

When I pass the datasource with only one bean as list to JasperFillManager, the report was successfully generated.. Here is the piece of code

 

*************

CustomerDAO customerDao = (CustomerDAO) context.getBean("customerDAO");

 

List customerList = customerDao.findAll();

JRBeanCollectionDataSource dataSource = new JRBeanCollectionDataSource(customerList);

 

....

....

JasperPrint jasperPrint = JasperFillManager.fillReport(CustomerReport.jasper", params, dataSource);

 

*************

 

But, when I passed more than one beans as follows, it fails with "Error retrieving field value from bean"..here is the code snippet

 

 

*************

CustomerDAO customerDao = (CustomerDAO) context.getBean("customerDAO");

List customerList = customerDao.findAll();

StudyDAO studyDao = (StudyDAO) context.getBean("studyDAO");

List studyList = studyDao.findAll();

ArrayList list = new ArrayList();

list.add(customerList);

list.add(studyList);

JRBeanCollectionDataSource dataSource = new JRBeanCollectionDataSource(list);

 

....

....

JasperPrint jasperPrint = JasperFillManager.fillReport(CustomerReport.jasper", params, dataSource);

 

*************

 

I would like to know, how to pass more than one beans into DataSource.

 

From my understanding, the included beans in datasource is not reachable to the Report generator engine..

 

Can I have the query inside the bean instead of having in report template, and pass the query list as datasource.

 

Please, give some tips what I am doing wrong..Or Am I in wrong track?

 

Thanks in advance.

Rameshkumar Ramasamy

[martynhiemstra]

No wonder. You are putting two totally different beans into your collection.

list.add(customerList);

list.add(studyList);

You are putting study and customer beans into the same list which is just screaming for problems in jasperreports. There is a field that exists in the study bean and not in the customer bean.

 

If you want to display two different bean lists then create 2 subreports. 1 for each bean and then put those two sub reports in the main report.

[peterramesh]

Hi Martynhiemstra,

 

Thanks for your reply. Since those tho beans (Customer and Study) has associations, I able to get the report by firing a single query using joins.

 

Now, the trick is. I have an ApplicationContext.xml file, which loads a list of hbm.xml files. I need to leverage these set of beans to the suitable datasource of JasperReports.

 

So then, the ReportEngine can use the needfull beans. Is it a valid approach to populate the list of beans to JasperReport, at one shot? Please give some tips or URLs related on this.

 

I looked at the org.springframework.ui.jasperreports.JasperReportsUtils class, but this may not be suitable for the usage of applicationContext.xml level.

 

Any help is greatly appreciated.

 

Rameshkumar Ramasamy.