tomcat - Java Webapp : generate File, 然后作为 JSP 的一部分显示？

Question

我想生成 jasper 报告并随后在内联框架(jsp 页面)中显示它们。我能想到的完成这项工作的唯一方法是将报告写入 pdf 文件，然后以某种方式引用该文件。

这是我的测试:它成功生成了文件。

@RequestMapping(value = "jaspertest", method = RequestMethod.GET)
public ModelAndView report() throws JRException, IOException {      
// TODO: compile here
//JasperReport jasperReport = JasperCompileManager.compileReport("path/to/myReport.jrxml");

String fileName = "/jasper/Blank_A4.jasper";
ClassLoader classLoader = getClass().getClassLoader();
File file = new File(classLoader.getResource(fileName).getFile());
InputStream jasperStream = new FileInputStream(file);

ReportSource reportSource = new ReportSource(this.realestateService);

Map<String,Object> params = new HashMap<>();
JasperReport jasperReport = (JasperReport) JRLoader.loadObject(jasperStream);
JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, params, reportSource);

String home = System.getProperty("user.home");
File reportFile = new File(home + "/tomcat/generated/generated_report.pdf");
reportFile.getParentFile().mkdirs();
if (!reportFile.exists())
    reportFile.createNewFile();

OutputStream outStream = new java.io.FileOutputStream(reportFile);

//final OutputStream outStream = response.getOutputStream();

JasperExportManager.exportReportToPdfStream(jasperPrint, outStream);
outStream.close();
return new ModelAndView("report/test","pdf", reportFile.getName());

但是我不明白，如果jsp页面现在可以引用使用过的pdf位置。我应该使用另一个位置吗？或者有更好的方法吗？

Answer 1

我发现，Jasper 也可以将报告呈现为 html。所以不再需要pdf了。可以将html注入(inject)jsp页面。

这是我的代码:

@RequestMapping(value = "show", method = RequestMethod.GET)
public ModelAndView report(@RequestParam(value = "report", required=true) String report) throws JRException, IOException {      

    String fileName = "/jasper/" + report;
    ClassLoader classLoader = getClass().getClassLoader();
    File file = new File(classLoader.getResource(fileName).getFile());
    InputStream jasperStream = new FileInputStream(file);

    JasperReport jasperReport = JasperCompileManager.compileReport(jasperStream);

    Map<String,Object> params = new HashMap<>();
    JRLoader.loadObject(jasperStream);
    JasperPrint jasperPrint = JasperFillManager.fillReport(jasperReport, params, reportSource);

    Exporter exporter;
    ByteArrayOutputStream out = new ByteArrayOutputStream();

    exporter = new HtmlExporter();
    exporter.setExporterOutput(new SimpleHtmlExporterOutput(out));

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

    String result = out.toString();

    return new ModelAndView("report/test","pdf", result);
  }