java - 以 HTML 格式导出 JasperReports

Question

下面的代码得到一个 byte[] 结果，适用于 PDF 和 XLSX。对于 HTML，会引发异常。

    JasperPrint jasperPrint = JasperFillManager.fillReport(report,
            params, dataSource != null ? new JRMapArrayDataSource(
                    dataSource) : new JREmptyDataSource());

    ByteArrayOutputStream out = new ByteArrayOutputStream();
    @SuppressWarnings("rawtypes")
    Exporter exporter;
    switch (format) {
    case PDF:
        exporter = new JRPdfExporter();
        break;
    case XLSX:
        exporter = new JRXlsxExporter();
        break;
    case HTML:
        exporter = new HtmlExporter();
        break;
    default:
        throw new ReportException("Unknown export format");
    }
    exporter.setExporterOutput(new SimpleOutputStreamExporterOutput(out));
    exporter.setExporterInput(new SimpleExporterInput(jasperPrint));
    exporter.exportReport();
    return out.toByteArray();

HTML 的异常(exception)是 exporter.exportReport(); 行

java.lang.ClassCastException: 

net.sf.jasperreports.export.SimpleOutputStreamExporterOutput cannot be cast to net.sf.jasperreports.export.HtmlExporterOutput
at net.sf.jasperreports.engine.export.HtmlExporter.exportReport(HtmlExporter.java:232)

v6.0 和 v5.6 的错误是一样的。这曾经在 v5.0 中工作(一些类在 v5.6 中被弃用)。

如何以各种格式(包括 HTML)导出报告？

Answer 1

对于 HTML 和其他格式:

import net.sf.jasperreports.engine.JRDataSource;
import net.sf.jasperreports.engine.JRException;
import net.sf.jasperreports.engine.JasperFillManager;
import net.sf.jasperreports.engine.JasperPrint;
import net.sf.jasperreports.engine.export.HtmlExporter;
import net.sf.jasperreports.engine.export.JRCsvExporter;
import net.sf.jasperreports.engine.export.JRPdfExporter;
import net.sf.jasperreports.engine.export.JRXmlExporter;
import net.sf.jasperreports.export.Exporter;
import net.sf.jasperreports.export.SimpleExporterInput;
import net.sf.jasperreports.export.SimpleHtmlExporterOutput;
import net.sf.jasperreports.export.SimpleOutputStreamExporterOutput;

public byte[] export(final JasperPrint print) throws JRException {
    final Exporter exporter;
    final ByteArrayOutputStream out = new ByteArrayOutputStream();
    boolean html = false;

    switch (getReportFormat()) {
        case HTML:
            exporter = new HtmlExporter();
            exporter.setExporterOutput(new SimpleHtmlExporterOutput(out));
            html = true;
            break;

        case CSV:
            exporter = new JRCsvExporter();
            break;

        case XML:
            exporter = new JRXmlExporter();
            break;

        case XLSX:
            exporter = new JRXlsxExporter();
            break;

        case PDF:
            exporter = new JRPdfExporter();
            break;

        default:
            throw new JRException("Unknown report format: " + getReportFormat().toString());
    }

    if (!html) {
        exporter.setExporterOutput(new SimpleOutputStreamExporterOutput(out));
    }

    exporter.setExporterInput(new SimpleExporterInput(print));
    exporter.exportReport();

    return out.toByteArray();
}

调用它使用:

JasperPrint print = JasperFillManager.fillReport(report, parameters, dataSource);
byte report[] = export(print);