Get values ​from a checkbox to create PDF

Question

I'm working with dataTable in JSP. I need you to generate a PDF file with the data attached to a document X; I can already generate the PDF, the problem I have is that I need to only attach in the PDF the values I select in a checkBox.

The code I have in JSP is as follows:

<h:column>
    <f:facet name="header">
        <h:outputText value="Sel." />
    </f:facet>
    <h:selectBooleanCheckbox
        value="#{edi.seleccion}"
        title="Seleccionar" />                                                       
</h:column> 

And the java code that generates the PDF file for me is as follows (a part of the code):

public void generarPdfDeclaracionLevante() throws IOException {
    
    List<RobEdifactTO> listaRadicados = new ArrayList<RobEdifactTO>();
    dataItemRobEdifactTO.setNuDo(dataItemRobAdminImpoTO.getNuDo());
    dataItemRobEdifactTO.setNuAnoDo(dataItemRobAdminImpoTO.getNuAnoDo());
    
    Integer cantidadDeclaraciones = robEdifactCtrl.consultarCantidadDeclaraciones(dataItemRobEdifactTO);
    Integer cantidadEdifact = robEdifactCtrl.consultarCantidadDeclaracionesLevante(dataItemRobEdifactTO);
    
    if(cantidadDeclaraciones > 0 && (cantidadEdifact > 0 || cantidadEdifact == 0)) {
        
        if(cantidadDeclaraciones == cantidadEdifact) {
            
            listaRadicados = robEdifactCtrl.consultaImprimeAceptacionDef(dataItemRobEdifactTO);
            if(listaRadicados.size() > 0)
            {
                
                HttpServletResponse response = (HttpServletResponse) this.getFacesContext().getExternalContext().getResponse();
                List<RobEdifactTO> listaDeclaraciones = new ArrayList<RobEdifactTO>();
                List < Document > listaHtmlJsoup = new ArrayList <> ( );
                
                PdfDocument pdf = new PdfDocument ( new PdfWriter(response.getOutputStream()) );
                PdfMerger merger = new PdfMerger ( pdf );
                
                // Configuracion de los header de la respuesta
                response.setContentType("application/pdf");
                response.addHeader("Content-Disposition", "attachment; filename=\"declaraciones.pdf\"");
                
                // Configuracion de objeto properties
                ConverterProperties properties = new ConverterProperties ( );
                // Configuracion de las fuentes del sistema
                properties.setFontProvider(new DefaultFontProvider(true, false, false));
                
                // Consulta de los datos que se van a imprimir
                listaDeclaraciones = listaRadicados;
                
                // Recorremos los html para modificar sus atributos
                for ( RobEdifactTO declaracion : listaDeclaraciones) {

                    listaHtmlJsoup.add ( generarFrenteDeclaracion(declaracion.getCaDeclaracionFrente()) );
                    listaHtmlJsoup.addAll ( generarDorsoDeclaracion(declaracion.getCaDeclaracionDorso()) );
                }                   
                
                try {
                    
                    for ( Document htmlItem : listaHtmlJsoup ) {
                        ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream ( );
                        PdfDocument paginaTemporalPdf = new PdfDocument ( new PdfWriter ( byteArrayOutputStream ) );
                        HtmlConverter.convertToPdf ( new ByteArrayInputStream ( htmlItem.toString ( ).getBytes ( StandardCharsets.UTF_8 ) ), paginaTemporalPdf, properties );
                        paginaTemporalPdf = new PdfDocument ( new PdfReader ( new ByteArrayInputStream ( byteArrayOutputStream.toByteArray ( ) ) ) );
                        merger.merge ( paginaTemporalPdf, 1, paginaTemporalPdf.getNumberOfPages ( ) );
                        paginaTemporalPdf.close ( );
                    }
                    contador = 0;
                    pdf.close ( );      
                    this.getFacesContext().getCurrentInstance().responseComplete();
                    
                } catch (IOException e) {
                    e.printStackTrace ( );
                }
            }
        }
    }
}