Question

我想从互联网网址下载csv文件。我已经尝试了一些我可以在网上找到并且无法下载的代码。

           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);

此代码无效

我使用了这个功能，它也不起作用。

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();
        }
    }

我在我的网址上尝试了一个简单的输入流，但这也不起作用。

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

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

现在，如果我输入任何其他网址，而不是myurl，bufferedreader会获取数据。如果我在浏览器中输入myurl，我会弹出一个保存或下载csv文件。所以问题不在于一个不正确的“myurl”

运行在“myurl”上的servelet /代码是否可能实际检查请求是否来自浏览器，然后才发送数据。

谢谢大家。使用httpclient，它适用于我。下载csv文件的代码，在本地保存，然后读取并解析所有令牌。

        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

你试过HttpClient lib吗？我以前用它来自动从网站上下载一套考试。

无法从java中的Internet url下载文件

1 个答案: