取消创建用于创建新PDF文件的outputteam的最佳方法？

Question

我在一个打开PDF文件的按钮中有SSJS，写入它的一些字段（Acroform），然后将文件下载到用户。所有的作品都很棒（使用pdfbox），但我想成为一名优秀的程序员，如果原始pdf文件不可用，请取消操作。否则，用户仍会被提示打开文件，但Adobe Reader报告该文件已损坏（显然会是）。我在我调用的Java类中执行我的pdf操作，并传递响应对象的outputStream。以下是我的SSJS。如果我测试来自newVal.outputPdf的ret值并将所有其他代码放在if语句中，那么我的XPage只是空白。我假设，因为响应和outputStream已经打开？

霍华德

importPackage(com.tlcc); 
var newVal = new PdfBoxTest(); 
importPackage(java.net); 
importPackage(java.lang); 
var con = facesContext.getExternalContext(); 
var response:com.ibm.xsp.webapp.XspHttpServletResponse = con.getResponse(); 

try {   
var writer:javax.servlet.ServletOutputStream = response.getOutputStream(); 


//get the stream 
var ret = newVal.outputPdf(writer, "http://localhost/pdfexportcc.nsf/certificate.pdf"); 

// setting response headers for browser 
print("Good output"); 
response.setContentType("application/pdf"); 
response.setHeader("Cache-Control", "no-cache"); 
response.setDateHeader("Expires", -1); 
response.setHeader("Content-Disposition", "attachment; filename=\"mypdf.pdf\""); 
writer.flush(); 
writer.close(); 
print("in close"); 
facesContext.responseComplete(); 
} catch (e) { 
    var errorMessage = "An error has occured: " + e.toString(); 
    _dump(errorMessage); 
    writer.close(); 
    response.sendError(500, errorMessage); 
} 

与所有的工作再次尝试是用Java语言实现。我从一个按钮调用了这个方法。与有效的网址工作正常，但当网址不好时，会引发错误。异常在OutputStream已被使用时无法获得Writer。

public boolean outputAllInJavaPdf() { 
    try { 
     FacesContext context = FacesContext.getCurrentInstance(); 

     XspHttpServletResponse response = (XspHttpServletResponse) context.getExternalContext().getResponse(); 

     ServletOutputStream writer = response.getOutputStream(); 
     InputStream docUrl = new URL("http://localhost/pdfexportcc.nsf/certifxxicate.pdf").openStream(); 
     pdfDoc = PDDocument.load(docUrl); 

     System.out.println("Number of pages is " + pdfDoc.getNumberOfPages()); 
     setField("Student", "James Namce"); 
     setField("CourseName", "XPages Development 2 for Notes and Domino 9"); 
     setField("Instructor", "John Smith"); 
     System.out.println("After set field"); 
     pdfDoc.save(writer); 
     pdfDoc.close(); 

     response.setContentType("application/pdf"); 
     response.setHeader("Cache-Control", "no-cache"); 
     response.setDateHeader("Expires", -1); 
     response.setHeader("Content-Disposition", "attachment; filename=\"mypdf.pdf\""); 
     writer.flush(); 
     writer.close(); 

     context.responseComplete(); 
     return true; 

    } catch (Exception e) { 
     System.out.println(e.getMessage()); 
     e.printStackTrace(); 
     return false; 
    } 
} 

Answer 1

它可能试图呈现您的Xpage，但您想自己控制响应。要防止Xpage的渲染并控制作者，请将rendered="false"添加到Xpage。

Answer 2

一切都取决于你告诉浏览器。

您使用PDF文件的内容类型。浏览器打开（下载）PDF文件。您放入的任何内容（例如错误页面）都被视为PDF文件的内容。 因此，如果PDF生成失败，请不要设置该内容类型并将浏览器重定向到错误页面，或者返回到原始XPage并附带说明。

public boolean outputAllInJavaPdf() { 
    try { 
     FacesContext context = FacesContext.getCurrentInstance(); 

     XspHttpServletResponse response = (XspHttpServletResponse) context.getExternalContext().getResponse(); 

     ServletOutputStream writer = response.getOutputStream(); 
     boolean servePdf = true; 
     try { 
      InputStream docUrl = new URL("http://localhost/pdfexportcc.nsf/certifxxicate.pdf").openStream(); 
      pdfDoc = PDDocument.load(docUrl); 
      // do something to validate PDF 
     } catch (Exception e) { 
      //no PDF 
      servePdf = false; 
     } 

     if (servePdf) { 
      System.out.println("Number of pages is " + pdfDoc.getNumberOfPages()); 
      setField("Student", "James Namce"); 
      setField("CourseName", "XPages Development 2 for Notes and Domino 9"); 
      setField("Instructor", "John Smith"); 
      System.out.println("After set field"); 
      pdfDoc.save(writer); 
      pdfDoc.close(); 

      response.setContentType("application/pdf"); 
      response.setHeader("Cache-Control", "no-cache"); 
      response.setDateHeader("Expires", -1); 
      response.setHeader("Content-Disposition", "attachment; filename=\"mypdf.pdf\""); 

     } else { 
      // take care of no PDF response - redirect? 
     } 
      writer.flush(); 
      writer.close(); 
      context.responseComplete(); 
      return true; 
    } catch (Exception e) { 
     System.out.println(e.getMessage()); 
     e.printStackTrace(); 
     return false; 
    } 
}