如何使用jsp显示excel，避免“没有输入源提供给导出器”。

Posted 2021-04-11

我已经编写了一些代码来展示网站中的excel。

但我得到了这个例外

net.sf.jasperreports.engine.JRRuntimeException：没有提供给导出器的输入源。

My code

在jsp中导入

<%@ 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代码导出到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);
        }
    %>

怎么解决这个问题？

答案

如果您没有使用旧版本的JasperReports，那么您使用的是弃用方法，最重要的是，您没有将JasperPrint传递给导出器。

没有输入源提供给导出器。

您需要使用JasperFillManager.fillReport填写报告

示例代码（jasper报告v5或更高版本）

JasperDesign jasperDesign = JRXmlLoader.load(new FileInputStream(reportFile));
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperDesign, parameters, conn);

JRXlsExporter exporter = new JRXlsExporter();
exporter.setExporterInput(new SimpleExporterInput(jasperPrint)); //The JasperPrint, filled report
exporter.setExporterOutput(new SimpleOutputStreamExporterOutput(xlsReport)); //Your ByteArrayOutputStream 

SimpleXlsReportConfiguration configuration = new SimpleXlsReportConfiguration();
configuration.setOnePagePerSheet(true);
configuration.setDetectCellType(true);
configuration.set //The other properties you like to set
exporter.setConfiguration(configuration);

exporter.exportReport();