I have a simple jsp I'm using java and I want to run a report by irreport from a link but I get an error

0

This is the servlet code, here is the report route:

package Controlador;

import Modelo.Conexion;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import net.sf.jasperreports.engine.JasperManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.JasperReport;

public class Reporte extends HttpServlet {

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    createReport(request, response);
}

@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    createReport(request, response);
}

protected void createReport(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
    //Mostrar el reporte en formato PDF
    response.setContentType("application/pdf");
    java.sql.Connection cn;
    try {
        cn = Conexion.getConexion();
        //El que obtiene el diseño del reporte
        JasperReport jasperReport = null;
        Map parameterMap = new HashMap();
        //La direccion del reporte
        String reporteJasper = request.getSession().getServletContext().getRealPath("reporte/classic.jasper");
        //Cargamos el reporte
        jasperReport = JasperManager.loadReport(new FileInputStream(reporteJasper));
        //Llenamos con informacion al reporte
        JasperPrint jasperPrint = JasperManager.fillReport(jasperReport, parameterMap, cn);
        OutputStream oS = null;
        oS = response.getOutputStream();
        //Y lo convertimos a PDF el reporte
        JasperManager.printReportToPdfStream(jasperPrint, oS);
        cn.close();
    } catch (SQLException ex) {
        ex.printStackTrace();
    } catch (Exception ex) {
        ex.printStackTrace();
    }


}
}

This is the error it throws:

SEVERE: java.lang.NullPointerException
at java.lang.Class.isAssignableFrom(Native Method)
at net.sf.jasperreports.engine.fill.JRFillTextField.getFormat(JRFillTextField.java:706)
at net.sf.jasperreports.engine.fill.JRFillTextField.evaluateText(JRFillTextField.java:394)
at net.sf.jasperreports.engine.fill.JRFillTextField.evaluate(JRFillTextField.java:368)
at net.sf.jasperreports.engine.fill.JRFillElementContainer.evaluate(JRFillElementContainer.java:258)
at net.sf.jasperreports.engine.fill.JRFillBand.evaluate(JRFillBand.java:499)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillColumnBand(JRVerticalFiller.java:2036)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillDetail(JRVerticalFiller.java:760)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReportStart(JRVerticalFiller.java:270)
at net.sf.jasperreports.engine.fill.JRVerticalFiller.fillReport(JRVerticalFiller.java:128)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:946)
at net.sf.jasperreports.engine.fill.JRBaseFiller.fill(JRBaseFiller.java:845)
at net.sf.jasperreports.engine.fill.JRFiller.fillReport(JRFiller.java:58)
at net.sf.jasperreports.engine.JasperFillManager.fillReport(JasperFillManager.java:417)
at net.sf.jasperreports.engine.JasperManager.fillReport(JasperManager.java:688)
at Controlador.Reporte.createReport(Reporte.java:47)
at Controlador.Reporte.doGet(Reporte.java:23)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:668)

And from this link I execute it:

<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
        <title>Inicio</title>
    </head>
   <body id="hhmenu"> 
       <link rel="stylesheet" type="text/css" href="hojaestilo.css">     
     
       
   
    </head>
    <div id="menu-wrapper">
    
     <ul id="hmenu"> 
         <li><a >Configuracion</a>
               <ul id="sub-menu"> 
                 
            <li><a href="Reporte">REPORTE</a> </li>
           
	

     
        

    </body>
</html>
    
asked by ALDO56 16.02.2018 в 13:49
source

1 answer

0

This error occurs when you have some version of iReports in your PC but you do not use that same version in the project , which causes this nullPointer that does not let you generate the report, what you have to verify that in the libraries are the same.

    
answered by 16.02.2018 в 17:15