net.sf.jasperreports.engine.JasperExportManager.exportReportToPdfStream(InputStream arg0, OutputStream arg1) 能夠實現匯出pdf到輸出流，但是因為JasperExportManager的exportReportToPdfStream沒有設計字型，導致有時候實現不了粗體的功能。

檢視JasperExportManager.exportReportToPdfStream的原始碼就明白了：

  public static void exportReportToPdfStream(JasperPrint jasperPrint, OutputStream outputStream)
    throws JRException
  {
    JRPdfExporter exporter = new JRPdfExporter();

    exporter.setParameter(JRExporterParameter.JASPER_PRINT, jasperPrint);
    exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, outputStream);

    exporter.exportReport();
  }

因此我們可以自己寫一段程式碼代替JasperExportManager.exportReportToPdfStream，如下

 JRPdfExporter exporter = new JRPdfExporter();
     Map fontsMap = new HashMap();
      
        fontsMap.put(new FontKey("宋體", true, false), new PdfFont("STSong-Light", "UniGB-UCS2-H", true, true, false));
        exporter.setParameter(JRExporterParameter.FONT_MAP, fontsMap);

整個實現頁面巢狀pdf預覽的程式碼如下：

Map ireportMap = new HashMap();
          ireportMap.put("clientNo", "D000000925");
         ireportMap.put("clientName", "測試客戶");
          ireportMap.put("barCode", "CS0100000002333");
         ireportMap.put("barCodeStr", "C  S  0  1  0  0  0  0  0  0  0  2  3  3  3");
         
         ireportMap.put("ImagePath", request.getRealPath("images/logo_print.jpg"));
         ClassLoader classLoader = RiskConfirmController.class.getClassLoader();
   OutputStream out = null;
   try {
    out = response.getOutputStream(); // 獲取頁面輸出流
    response.setContentType("application/pdf; charset=utf-8"); // 設定頁面型別及編碼
    response.setDateHeader("Expires", 0); // 清除頁面快取
    //risk_controler_confirm.jasper   riskcontrolerconfirm
    response.setHeader("Content-Disposition", "inline;filename="+ URLEncoder.encode("risk_controler_confirm.pdf", "utf-8")); // 設定檔名
    JasperPrint jPrint = JasperFillManager.fillReport(classLoader.getResourceAsStream("risk_controler_confirm.jasper"),ireportMap, new JREmptyDataSource()); // 模板填充資料
   
    JRDesignReportFont jrfont =  new JRDesignReportFont();
    //JasperExportManager.exportReportToPdfStream(jPrint, out); // 生成PDF輸出流
         JRPdfExporter exporter = new JRPdfExporter();
     Map fontsMap = new HashMap();
      
        fontsMap.put(new FontKey("宋體", true, false), new PdfFont("STSong-Light", "UniGB-UCS2-H", true, true, false));
        exporter.setParameter(JRExporterParameter.FONT_MAP, fontsMap);
        exporter.setParameter(JRExporterParameter.JASPER_PRINT, jPrint);
        exporter.setParameter(JRExporterParameter.OUTPUT_STREAM, out);
        exporter.exportReport();
    if (out != null){
     out.flush();
    }