如何訪問servlet並下載附件？

Question

我有試圖讓一個HTTP調用我的servlet下面的代碼片段：

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) { 
    } 

我調試輸出：

[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（從上面的代碼單獨的文件）我生成下載Excel文件：

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

我在這裏的問題是，從我的代碼生成（如上面的調試輸出）的URL，我可以訪問我的servlet一nd我設法得到另存爲對話框。

我想獲取在我的代碼中使用生成的文件的內容。有沒有什麼辦法可以從我的代碼中獲取附件，以字節流或任何其他格式？

---

編輯＃3：盪滌頂部

Answer 1

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

我發現代碼中沒有錯誤。
我相信你想要將輸入流中的內容轉換爲HSSFWorkbook對象。
以下代碼片段將幫助你。

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 2

檢查wbBook.write(oOutStrm);東西是否已經寫入的OutputStream，還需要密切之前調用它oOutStrm.flash()。

Answer 3

當您在瀏覽器中輸入URI時，您正在執行GET請求。然而，您的客戶端Java代碼會生成POST請求，並在正文中發送參數，而不是URI。

您可能想查看HTTP跟蹤並進行比較。

Answer 4

我懷疑問題在於OutputStream oOutStrm = res.getOutputStream();。

我敢打賭res是HttpServletResponse它返回一個ServletOutputStream適合在響應中寫入二進制數據。 servlet容器不編碼的二進制數據

檢查API

所以，你可能不會得到除了文件名什麼。

在Servlet的嘗試

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