How to send List<Object[]> as datasource to jasper report?

Question

I want to generate a JasperReports report from two tables. Tables are emp and desig

Respected bean classes are ,

@Entity
@Table(name = "desg")
public class Designation {

    @Id
    @Column(name="Empid")
    private int eId;
    @Column(name="Designation")
    private String Designation;

    // getters and setters
}

@Entity
@Table(name = "emp")
public class Employee {

    @Id
    @GeneratedValue
    @Column(name="Eid")
    private int eId;
    @Column(name="Name")
    private String name;
    @Column(name="Address")
    private String address;
    @Column(name="Salary")
    private int salary;

    // getters and setters
}

The report with only one table is working fine . I use Hibernate to create list of bean object. I request for report as follow,

    List<Object[]> lst= sessio.createQuery("select e.eId, e.name, d.Designation From Employee e, Designation d where e.eId=d.eId ").list();

    String reportSourceFile="E:\\classes\\report4.jrxml";

    JasperReport jasperReport = null;
    JasperDesign jasperDesign = null;
    Map parameters = new HashMap();  
    parameters.put("Title", "The EMP Report"); 
    try {
    jasperDesign = JRXmlLoader.load(reportSourceFile);
    jasperReport = JasperCompileManager.compileReport(jasperDesign);
    byte[] byteStream = JasperRunManager.runReportToPdf(jasperReport, parameters, new JRBeanCollectionDataSource(emplst)); // what to change instead of emplst
    OutputStream outStream = response.getOutputStream();
    response.setHeader("Content-Disposition","filename=myReport.pdf");
    response.setContentType("application/pdf");
    response.setContentLength(byteStream.length);
    outStream.write(byteStream,0,byteStream.length); 

    } catch (JRException e1) {
        e1.printStackTrace();
    }

If I send my emplst it works fine but I want lst to be print in report. How to send lst object to JasperReports 's report and how to get in iReport tool?

Answer 1

In your JRXML use import tag

      <import value="yourPackageName.Employee">

and Create a Parameter in JRXML having data type as java.lang.Object lets say myEmployee is the parameter name

then pass Employee Object as parameter to JRXML

Map<String,Object> map=new HashMap<String,Object>();
map.put("myEmployee",yourEmployeeObject);

Now your employee class Object is present in JRXML , you can call getters from JRXML to get the State of Object ( ie attributes of Object )

Answer 2

you can:
1) create wrapper class for your joined objects to pass to JRBeanCollectionDataSource
or
2) Create own implementation of JRDataSource
or
3) fill report based on sql, not datasource