JasperReports:从servlet调用报告

Question

我是新手JasperReports,不知道如何从servlet调用jasper文件.我的报告包含饼图.

Answer 1

您可以准备Jasper文件并将其流式传输到客户端.

bytes[] byteStream = JasperRunManager.runReportToPdf("myJasperReport.jasper",paramMap,databaseConn);

OutputStream outStream = servletResponse.getOutputStream();
response.setHeader("Content-Disposition","inline, filename=myReport.pdf");
response.setContentType("application/pdf");
response.setContentLength(byteStream.length);
outStream.write(bytes,0,bytes.length);

Answer 2

这是在 Servlet 文件中创建的虚拟报告。

它与普通 Java 类中的相同。

只需确保您的 jasper 报告类的导入位于文件顶部即可。

以下示例从 XML 数据源构建报告。

public class JasperServlet extends HttpServlet {
    public void doGet(HttpServletRequest req, HttpServletResponse res)
            throws ServletException, IOException {
        try {
            String reportFile = "myJasperReport.jrxml";
            File outputFile = new File("Report.pdf");
            HashMap hm = new HashMap();

            DocumentBuilderFactory documentBuilderFactory = DocumentBuilderFactory
                    .newInstance();
            DocumentBuilder documentBuilder = documentBuilderFactory
                    .newDocumentBuilder();
            Document document = documentBuilder.parse(new File("myXml.xml"));

            // Compile the report
            JasperReport report = JasperCompileManager
                    .compileReport(reportFile);
            JRXmlDataSource xml = new JRXmlDataSource(document, "/xml/root");
            // Fill the report
            JasperPrint print = JasperFillManager.fillReport(report, hm, xml);
            // Create an Exporter
            JRExporter exporter = new JRPdfExporter();
            exporter.setParameter(JRExporterParameter.OUTPUT_FILE, outputFile);
            exporter.setParameter(JRExporterParameter.JASPER_PRINT, print);
            // Export the file
            exporter.exportReport();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}