Question

What is the correct way to create a report using a custom object list?
I’ve been trying to achieve this for a day or two, but nothing works.
I created a custom JRDataSource and a factory that creates such object.

Here’s the code for the DataSource:

public class ViajeDataSource implements JRDataSource
{

private int index;
private ArrayList<Viaje> viajes;

public ViajeDataSource()
{
    this.viajes=new ArrayList<>();
}

@Override
public boolean next() throws JRException 
{
    this.index++;
    return (index<this.viajes.size());
}

@Override
public Object getFieldValue(JRField jrf) throws JRException 
{
    Object value = null;
    Viaje viaje=this.viajes.get(this.index);
    if (jrf.getName().equals("FECHA"))
    {
        return viaje.getFecha();
    }
    switch(jrf.getName())
    {
        case "FECHA":
            value=viaje.getFecha();
            break;
        case "NombrePersona":
            value=viaje.getNombrePersona();
            break;
        case "NombreEmpresa":
            value=viaje.getNombreEmpresa();
            break;
        case "Observacion":
            value=viaje.getObservacion();
            break;
        case "Importe":
            value=viaje.getTarifa();
            break;
        case "Demora":
            value=viaje.getDemora();
            break;
        case "Total":
            value=viaje.getTotal();
            break;
        case "Peaje":
            value=viaje.getPeaje();
            break;
    }
    return value;
}

Pay attention to the field named FECHA
I added the following expression in IReport designer: $F{FECHA}, but when previewing, the IDE says no “FECHA” field was found. Any ideas why?

Answer 1

This approach worked for me:
Instead of a custom datasource, I created a custom dataSourceProvider, and selected JRDataSource when creating the datasource.
This, combined to IReports standalone utility, allowed me to design the report with sample data from my collection