Ich habe einen Code geschrieben, der Excel auf einer Website anzeigt.

Aber ich bekomme diese Ausnahme

net.sf.jasperreports.engine.JRRuntimeException: Dem Exporter wurde keine Eingabequelle bereitgestellt.

Mein Code

import in jsp

<%@ page import="java.io.*"%>
<%@ page import="java.sql.Connection"%>
<%@ page import="java.sql.DriverManager"%>
<%@ page import="java.util.HashMap"%>
<%@ page import="java.util.Map"%>
<%@ page import="net.sf.jasperreports.engine.*"%>
<%@ page import="java.io.ByteArrayOutputStream"%>
<%@ page import="net.sf.jasperreports.view.JasperViewer"%>
<%@ page import="net.sf.jasperreports.engine.export.*"%>

jsp Code zum Exportieren nach excel

        <%
        Connection conn = null;
        String no1 = request.getParameter("no1");
        String no2 = request.getParameter("no2");

        System.out.println("get value " + no1 + " " +no2);
        try {
            Class.forName("com.mysql.jdbc.Driver").newInstance();
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/ams2"
                                                ,"root","passwd1234");
            File reportFile = new File (application.getRealPath("//jasper//report//Blank_A4_2.jasper"));
            Map parameters = new HashMap();

            parameters.put("no1",no1);
            parameters.put("no2",no2);
            System.out.println("123 "+parameters);

            ByteArrayOutputStream xlsReport = new ByteArrayOutputStream();
            JRXlsExporter exporter = new JRXlsExporter();
            exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, xlsReport);
            exporter.setParameter(JRExporterParameter.OUTPUT_FILE, "C:\\");
            exporter.setParameter(JRExporterParameter.OUTPUT_FILE_NAME, "sample.xls");
            exporter.exportReport();

            byte bytes[] = new byte[10];
            bytes = xlsReport.toByteArray();
            response.setContentType("application/vnd.ms-excel");

            response.setContentLength(bytes.length);
            xlsReport.close();
            ServletOutputStream outStream = response.getOutputStream();
            outStream.write(bytes,0,bytes.length);
            outStream.flush();
            outStream.close();

        } catch (Exception ex) {
            out.println("Error " + ex);
        }
    %>

Wie kann das behoben werden?