Grails将HttpInputStream渲染为pdf

Question

使用以下代码，我得到了这样的坏输出：

%PDF-1.4%���� 4.0目标

而不是pdf。代码如下：

URL url = new URL(urlStr)
URLConnection connection = url.openConnection();
response.contentType = 'application/pdf'
response.setHeader("Content-Disposition","Attachment; filename=gdoc.pdf")
def bytes = connection.getInputStream().getBytes()
response.getOutputStream().write(bytes)
response.outputStream.flush()
response.outputStream.close()

/*
  //writing to a pdf file works perfectly
  def outputStream =  new FileOutputStream(new File("gdoc/abc.pdf"));
  outputStream.write(bytes)
  outputStream.close()
*/

如何在浏览器中获取实际的pdf输出。

Answer 1

我通过执行以下代码解决了问题：

控制器：

    def bytes = SendHttpService.executeGetBinary("http://app.com",  
                                                  "/pdf/", params)
    response.setHeader("Expires", "0");
    response.setHeader("Cache-Control","must-revalidate, post-check=0, pre-check=0");
    response.setHeader("Pragma", "public");
    response.setHeader("Content-Disposition", "inline; filename=\"relatorioGerencial.pdf\"");
    response.setContentType("application/pdf");
    response.setContentLength(bytes.length);
    ServletOutputStream ouputStream = response.getOutputStream();
    ouputStream.write(bytes,0,bytes.length);
    ouputStream.flush();
    ouputStream.close();

这里，像第一个示例一样发送请求以返回流，注意contentType是二进制的

    def executePostBinary = { String httpUrl, String dataBody, String path, query = null, method = Method.POST->

    def http = new HTTPBuilder()
    try{
        http.request( httpUrl , method , ContentType.BINARY ) { req ->

            uri.path = path
            uri.query = trataQuery(query)
            headers.'User-Agent' = "Mozilla/5.0 Firefox/3.0.4"
            headers.Accept = ContentType.BINARY
            if(method==groovyx.net.http.Method.POST && dataBody!=null){
                body = dataBody
            }

            response.success = { resp, inputStream  ->
                inputStream.bytes

            }

            response.'404' = {
                'Not found'
            }
        }
    }catch(HttpResponseException e){
        println "Error "+e
        println "Error Code "+e.statusCode
        return false
    }
}

Answer 2

这假设您在控制器中，控制器方法末尾的返回null确保Grails不会尝试渲染任何内容。此外，使用Apache commons复制内容可以避免在响应中发送之前将整个文件下载到内存中。这是根据生产代码修改的，我在生产代码中做了一些非常类似的事情。Grails版本1.3.7和2.0.4。

URL url = new URL(urlStr)

response.setContentType("application/pdf")
response.setHeader("Content-disposition", "attachment;filename=gdoc.pdf")

// this will actually buffer/stream the file in 8k chunks instead of reading the entire file into memory.
org.apache.commons.io.IOUtils.copy(url.openStream(), response.outputStream)
response.outputStream.flush()
response.outputStream.close()

// make sure Grails doesn't render anything for the request.
return null

Answer 3

您是否在iframe中尝试响应？如果是这样，首先尝试直接在新窗口中打开输出，看看它是否打开。

如果它打开，尝试将您的控制器映射到类似abc.pdf的东西，以便您指向的url成为 /something/abc.pdf.