Java: Generating Report in iReport Between Two Dates Timestamp

I am finalizing a small system made in Java and MySQL and with reports being generated by iReport and need to generate a report displaying values between two dates.

TheproblemsarewhenItrytopasstheseparametersthroughJava:

try{//UsandoaclasseHashMapparacriarumfiltroHashMapfiltroInicio=newHashMap();HashMapfiltroFinal=newHashMap();filtroInicio.put("inicial", Timestamp.valueOf("2018-04-20 00:00:00"));
            filtroFinal.put("final", Timestamp.valueOf("2018-04-21 23:59:59"));
            //Usando a classe JasperPrint para preparar a impressão do relatório
            JasperPrint print = JasperFillManager.fillReport("C:/Users/Master/Documents/InfoX/reports/caixa2.jasper", filtroInicio, conexao);

            //Exibindo o relatório através da classe JasperViewer
            JasperViewer.viewReport(print, false);
        } catch (Exception e) {
            JOptionPane.showMessageDialog(null, e);
        }

First problem: With the above code, at the time of generating the report through the system, it informs that the document does not contain pages , as if the parameters were null .

Second problem: If you notice this code snippet: JasperPrint print = JasperFillManager.fillReport("C:/Users/Master/Documents/InfoX/reports/caixa2.jasper", filtroInicio, conexao); Summer I can only pass a parameter, which is the initial one, how would I go about passing the two parameters through Java? / p>

Third problem: In the future I will still need to replace the date values entered within the parentheses by values obtained through a JTextField.

I need help urgently, thank you in advance! If the doubt was not very clear, I will try to clarify it to the maximum.