JasperReports xls download via Spring MVC

This is an extension to the JasperReport step by step tutorial to demonstrate how to generate an Excel file. This extends the tutorial on stand-alone excel file to demonstrate how to produce xls as a file attachment via Spring MVC RESTful service call.

The controller class will be something like

 
//...
@Controller
public class MyApproller
{

    @Resource(name = "myAppService")
    private MyAppService myAppService;
 
 @Resource(name = "reportWriter")
    private ReportWriter reportWriter;

 @RequestMapping(
            value = "/person.xls",
            method = RequestMethod.GET,
            produces = "application/vnd.ms-excel")
 @ResponseBody
 public void getCashForecastCSV(HttpServletResponse response) throws Exception
 {
  //get the report data from the service layer
  Collection<Person> reportData = myAppService.getReportData();
  
  //get the parameters as a Map from the service layer
  Map<String, Object> reportParameters = myAppService.getReportParameters();
  
  //generate the xls report 
  byte[] xlsAsStringForPerson = reportWriter.getXlsAsStringForPerson(reportData, reportParameters);
  
  response.setContentType("application/vnd.ms-excel");
  response.addHeader("Content-Disposition", "attachment; filename=" + "person.xls");
  
  //since binary, write it as stream
  response.getOutputStream().write(xlsAsStringForPerson);
 }

//..
}

 
//...........
@Service(value = "myAppService")
public class MyAppServiceImpl implements MyAppService {

 public Collection<Person> getReportData()
    {
        //declare a list of object
        List<Person> data = new LinkedList<Person>();
        Person p1 = new Person();
        p1.setFirstName("John");
        p1.setSurname("Smith");
        p1.setAge(Integer.valueOf(5));
        data.add(p1);
        return data;
    }
    
    public Map<String, Object> getReportParameters()
    {
        Map<String, Object> params = new HashMap<String, Object>();
        params.put("footerText", "Just to demonstrate how to pass parameters to report");
        return params;
    }
}

Finally, the writer class the creates the xls file from the data

 
//..
import java.io.ByteArrayOutputStream;
import java.io.InputStream;
import java.util.Collection;
import java.util.Map;

import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperCompileManager;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;
import net.sf.jasperreports.engine.data.JRBeanCollectionDataSource;
import net.sf.jasperreports.engine.design.JasperDesign;
import net.sf.jasperreports.engine.export.JRXlsExporter;
import net.sf.jasperreports.engine.export.JRXlsExporterParameter;
import net.sf.jasperreports.engine.xml.JRXmlLoader;

import org.springframework.stereotype.Component;
//...

@Component(value = "reportWriter")
public class JasperReportWriterImpl implements ReportWriter
{
    
    public static JasperDesign jasperDesign;
    public static JasperPrint jasperPrint;
    public static JasperReport jasperReport;
    public static String reportTemplateUrl = "jasper/person-template.jrxml";
    
    public byte[] getXlsAsStringForPerson(Collection<Person> reportData, Map<String, Object> reportParameters)
    {
        ByteArrayOutputStream output = null;
        
        try
        {
            InputStream resourceAsStream = Thread.currentThread().getContextClassLoader()
                    .getResourceAsStream(reportTemplateUrl);
            //get report file and then load into jasperDesign
            jasperDesign = JRXmlLoader.load(resourceAsStream);
            //compile the jasperDesign
            jasperReport = JasperCompileManager.compileReport(jasperDesign);
            
            output = new ByteArrayOutputStream();
            
            //fill the ready report with data and parameter
            jasperPrint = JasperFillManager.fillReport(jasperReport, reportParameters,
                    new JRBeanCollectionDataSource(
                            reportData));
            
            //coding for Excel
            JRXlsExporter exporterXls = new JRXlsExporter();
            exporterXls.setParameter(JRXlsExporterParameter.JASPER_PRINT, jasperPrint);
            exporterXls.setParameter(JRXlsExporterParameter.OUTPUT_STREAM, output);
            exporterXls.setParameter(JRXlsExporterParameter.IS_ONE_PAGE_PER_SHEET, Boolean.TRUE);
            exporterXls.setParameter(JRXlsExporterParameter.IS_DETECT_CELL_TYPE, Boolean.TRUE);
            exporterXls.exportReport();
            
        }
        catch (JRException e)
        {
            e.printStackTrace();
        }
        
        return output.toByteArray();
    }
}