如何访问 servlet 和下载附件

Question

我有以下代码片段试图对我的servlet进行HTTP调用：

    try {
        // Construct data
        String data = URLEncoder.encode("rpt_type", "UTF-8") + "=" + URLEncoder.encode(reportType, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_project", "UTF-8") + "=" + URLEncoder.encode(reportProject, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_mrv_creator", "UTF-8") + "=" + URLEncoder.encode(reportMrvCreator, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_gi_recipient", "UTF-8") + "=" + URLEncoder.encode(reportGiRecipient, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_plant", "UTF-8") + "=" + URLEncoder.encode(reportPlant, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_sloc", "UTF-8") + "=" + URLEncoder.encode(reportStorageLoc, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_gi_no", "UTF-8") + "=" + URLEncoder.encode(reportGiNo, "UTF-8");
        data += "&" + URLEncoder.encode("date_sap_gi_fr", "UTF-8") + "=" + URLEncoder.encode(reportDateGiFrom, "UTF-8");
        data += "&" + URLEncoder.encode("date_sap_gi_to", "UTF-8") + "=" + URLEncoder.encode(reportDateGiTo, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_partno", "UTF-8") + "=" + URLEncoder.encode(reportPartNo, "UTF-8");
        data += "&" + URLEncoder.encode("rpt_so_no", "UTF-8") + "=" + URLEncoder.encode(reportSvcOrderNo, "UTF-8");
        data += "&" + URLEncoder.encode("date_scan_fr", "UTF-8") + "=" + URLEncoder.encode(reportDateScanFrom, "UTF-8");
        data += "&" + URLEncoder.encode("date_scan_to", "UTF-8") + "=" + URLEncoder.encode(reportDateScanTo, "UTF-8");
        System.out.println("[data]n" + data);
        // Send data
        String urlString = "http://localhost:8080/aerobook/GIStatusReportDownload?" + data;
        System.out.println("[url] " + urlString);
        URL url = new URL(urlString);
        URLConnection conn = url.openConnection();
        //conn.setDoOutput(true);
        //OutputStreamWriter wr = new OutputStreamWriter(conn.getOutputStream());
        //wr.write(data);
        //wr.flush();
        // Get the response
        BufferedReader rd = new BufferedReader(new InputStreamReader(conn.getInputStream()));
        String line;
        while ((line = rd.readLine()) != null) {
            System.out.println(line);
        }
        //wr.close();
        rd.close();
    } catch (Exception e) {
    }

我的调试输出：

[data]
rpt_type=d&rpt_project=aaa&rpt_mrv_creator=bbb&rpt_gi_recipient=ccc&rpt_plant=ddd&rpt_sloc=eee&rpt_gi_no=fff&date_sap_gi_fr=02%2F05%2F2012&date_sap_gi_to=03%2F05%2F2012&rpt_partno=ggg&rpt_so_no=hhh&date_scan_fr=26%2F05%2F2012&date_scan_to=31%2F05%2F2012
[url] http://localhost:8080/aerobook/GIStatusReportDownload?rpt_type=d&rpt_project=aaa&rpt_mrv_creator=bbb&rpt_gi_recipient=ccc&rpt_plant=ddd&rpt_sloc=eee&rpt_gi_no=fff&date_sap_gi_fr=02%2F05%2F2012&date_sap_gi_to=03%2F05%2F2012&rpt_partno=ggg&rpt_so_no=hhh&date_scan_fr=26%2F05%2F2012&date_scan_to=31%2F05%2F2012

在我的 servlet 上（在与上述代码不同的文件中），我生成一个 Excel 文件以供下载：

    res.setContentType(sContentType);
    res.setHeader("Content-Disposition", "attachment;filename="" + sExcelFileName + """);
    OutputStream oOutStrm = res.getOutputStream();
    wbBook.write(oOutStrm);
    oOutStrm.close();

我

在这里的问题是，从我的代码生成的 URL（如上面的调试输出所示），我可以访问我的 servlet，并设法获得"另存为"对话框。

我想获取生成的文件内容以在我的代码中使用。有什么方法可以从我的代码、字节流或任何其他格式中获取附件？

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编辑#3：清理顶部

Answer 1

当您在浏览器中输入 URI 时，您正在执行 GET 请求。但是，客户端 Java 代码会生成 POST 请求，并在正文（而不是 URI）中发送参数。

您可能需要查看 HTTP 跟踪并进行比较。

Answer 2

I want to get the contents of the excel file on my code, but so far it's not working.

我在代码中没有发现任何错误。
我相信您想将内容从输入流转换为HSSFWorkbook对象。
以下代码片段将为您提供帮助。

java.net.URLConnection conn = url.openConnection();  
java.io.InputStream is = conn.getInputStream();  
org.apache.poi.hssf.usermodel.HSSFWorkbook workBook = new org.apache.poi.hssf.usermodel.HSSFWorkbook( is );  
System.out.println( "Number of Sheets: " + workBook.getNumberOfSheets() );  
org.apache.poi.hssf.usermodel.HSSFSheet sheet = workBook.getSheetAt( 0 );  
System.out.println( "Sheet Name: " + sheet.getSheetName() );  
// rest of your code to handle the captured workBook
// cheers

Answer 3

检查wbBook.write(oOutStrm);是否有任何内容写入 outputStream，在关闭它之前还需要调用oOutStrm.flash()。

Answer 4

我怀疑问题出在OutputStream oOutStrm = res.getOutputStream();.

我敢打赌res是HttpServletResponse的，它返回一个适合在响应中写入二进制数据的ServletOutputStream。servlet 容器不对二进制数据进行编码

检查接口

因此，除了文件名之外，您可能什么也得不到。

在 Servlet 中尝试

FileOutputStream stream = new FileOutputStream("c:/excel/Book1.xls");
workBook.write(stream);