無法從java下載網絡文件中的url

Question

我想從互聯網網址下載csv文件。 我已經嘗試了我可以在網上找到並且無法下載的所有代碼。

  URL google = new URL("myurl"); 
      ReadableByteChannel rbc = Channels.newChannel(google.openStream()); 
      FileOutputStream fos = new FileOutputStream("C://excelsheet.csv"); 
      fos.getChannel().transferFrom(rbc, 0, 1 << 24); 

此代碼不能正常工作

我用這個功能，它不是工作壓力太大。

public stacvoid saveUrl(String filename, String urlString) throws MalformedURLException, IOException 
    { 
     BufferedInputStream in = null; 
     FileOutputStream fout = null; 
     try 
     { 
       in = new BufferedInputStream(new URL(urlString).openStream()); 
       fout = new FileOutputStream(filename); 

       byte data[] = new byte[1024]; 
       int count; 
       while ((count = in.read(data, 0, 1024)) != -1) 
       { 
         fout.write(data, 0, count); 
       } 
     } 
     finally 
     { 
       if (in != null) 
         in.close(); 
       if (fout != null) 
         fout.close(); 
     } 
    } 

我嘗試了一個簡單的輸入流在我的網址，這不工作了。

  URL oracle = new URL("myurl"); 
      URLConnection yc = oracle.openConnection(); 

     BufferedReader br = new BufferedReader(new InputStreamReader(
              yc.getInputStream())); 

現在不是myurl，如果我輸入任何其他url，bufferedreader確實會獲取數據。 如果我在瀏覽器中輸入myurl，我會彈出一個窗口來保存或下載csv文件。 所以問題不在於不正確的「myurl」

「myurl」上運行的servlet /代碼是否有可能實際檢查請求是否來自瀏覽器，然後才發送數據。

謝謝大家。使用httpclient，它適用於我。下載一個csv文件的代碼，將其保存在本地，然後讀取它並解析所有的令牌。

 HttpClient httpclient = new DefaultHttpClient(); 
     HttpGet httpget = new HttpGet("your url to download"); 
     HttpResponse response = httpclient.execute(httpget); 

      System.out.println(response.getProtocolVersion()); 
      System.out.println(response.getStatusLine().getStatusCode()); 
      System.out.println(response.getStatusLine().getReasonPhrase()); 
      System.out.println(response.getStatusLine().toString()); 
      HttpEntity entity = response.getEntity(); 
      if (entity != null) { 
       FileOutputStream fos = new java.io.FileOutputStream("C://excelsheet.csv"); 
       entity.writeTo(fos); 
       fos.close(); 
      } 

      //create BufferedReader to read csv file 
     BufferedReader br = new BufferedReader(new FileReader("C://excelsheet.csv")); 
     String strLine = ""; 
     StringTokenizer st = null; 
     int lineNumber = 0, tokenNumber = 0; 
     while((strLine = br.readLine()) != null) 
           { 
             lineNumber++; 

             //break comma separated line using "," 
             st = new StringTokenizer(strLine, ","); 

             while(st.hasMoreTokens()) 
             { 
               //display csv values 
               tokenNumber++; 
               System.out.println("Line # " + lineNumber + 
                   ", Token # " + tokenNumber 
                   + ", Token : "+ st.nextToken()); 
             } 

             //reset token number 
             tokenNumber = 0; 

           } 
     } 
     catch (Exception e) { 
      System.out.println("insdie the catch part"); 
      System.out.println(e.toString()); 
     } 

Answer 1

您是否試過HttpClient lib？ 我以前用它自動從網站下載一組考試。