java - URL 连接获取输入流失败

Question

我正在尝试查找服务器中目录的大小。所以我已经定义了类来获取服务器的访问权限并找到大小:

public class SoftwareDownload {
  private String inputUrl;
  private String destinationPath;
  private String userName;
  private String userPassword;
  private URL url = null;
  private URLConnection uc = null;
  private String userpass;
  private String basicAuth;
  private boolean isAuthendicated = false;

  public SoftwareDownload(String inputUrl, String destinationPath, String userName, String userPassword) {
    this.inputUrl = inputUrl;
    this.destinationPath = destinationPath;
    this.userName = userName;
    this.userPassword = userPassword;
    userpass = userName + ":" + userPassword;
    basicAuth = "Basic " + javax.xml.bind.DatatypeConverter.printBase64Binary(userpass.getBytes());
    try {
      url = new URL(this.inputUrl);
      try {
        uc = url.openConnection();
        uc.setRequestProperty ("Authorization", basicAuth);
        isAuthendicated = true;
      } catch (IOException e) {
        // TODO Auto-generated catch block
        System.out.println("UC check nul");
        e.printStackTrace();
      }
    } catch (MalformedURLException e) {
      // TODO Auto-generated catch block
      System.out.println("Connection check nul");
      e.printStackTrace();
    }
  }


    public long httpFindSoftwarePackage ( int count,boolean isSizeRequired) throws IOException {
    long packageByteCnt = 0;

    InputStream inStream = uc.getInputStream();
    InputStreamReader streamReader=new InputStreamReader(inStream);
    BufferedReader inputStream = new BufferedReader(streamReader);
    String line = "";
    while(line != null) {
      line = inputStream.readLine();
      if ( (line != null ) && ( line.startsWith("<a href=")) ) {
        Document doc = Jsoup.parse(line);
        Element link = doc.select("a").first();
        String linkHref = link.attr("href");
        String sourceDir = inputUrl+"/"+linkHref;
        SoftwareDownload downloadimage = new SoftwareDownload (sourceDir,null,userName,userPassword);
        if( linkHref.endsWith("/") == true ) {
          packageByteCnt+=downloadimage.httpFindSoftwarePackage(count+1,isSizeRequired);
        }
        else
        {
            packageByteCnt+=downloadimage.uc.getContentLengthLong();
        }
      }
    }
    return packageByteCnt;
  }
}

Class Main:
  public static void main(final String[] args) throws IOException {
    String httpurl ="http://rb-cmbinex.com/software/rfs/16.2S813/rfs_ni";
    String destiDir = "d:/TestDirectory";
    String user = "username";
    String password = "Password#123";

    SoftwareDownload download = new SoftwareDownload(httpurl, null, user, password);

   System.out.println("Total Package Size : " + download.httpFindSoftwarePackage(0, true));
}

当我单独运行这个程序时，我可以读取目录的大小。但是，同时当我将这个 SoftwareDownload 调用集成到我的 spring boot java 应用程序时，我得到了这个 IO 异常，

java.io.IOException:服务器返回 HTTP 响应代码:500 用于 URL:http://rb-cmbinex.com/software/rfs/16.2S813/rfs_ni/rootfs/ 在 sun.net.www.protocol.http.HttpURLConnection.getInputStream0(未知来源) 在 sun.net.www.protocol.http.HttpURLConnection.getInputStream(未知来源) 在 com.bosch.boardfarm.model.SoftwareDownload.httpFindSoftwarePackage(SoftwareDownload.java:113) 在 com.bosch.boardfarm.model.SoftwareDownload.httpFindSoftwarePackage(SoftwareDownload.java:143)

然后我发现IO异常来自行(在获取连接的URL的输入流时)， InputStream inStream = uc.getInputStream();

有人可以帮助解决这个问题吗。

Answer 1

500 错误意味着:

500 Internal Server Error

A generic error message, given when an unexpected condition was encountered and no more specific message is suitable.

简而言之，您尝试与之通话的服务器出了点问题。您可以通过阅读和打印出错误流的内容来获得更多信息。但是，它可能是空的，或者是一个不提供任何有用信息的“通用”错误页面。

---

The server is active and running.

你知道这个是因为......？ (当我试图与服务器对话时，我只是超时了。)

如果这是您的服务器，请检查日志文件以查看是否有与代码 500 响应对应的日志消息。 (您可能想暂时提高日志记录级别...)

uc.getResponseCode(), uc.getResponseMessage() and uc.getErrorStream() these options are not available in the URLConnection

将连接转换为 HttpURLConnection，然后您可以调用这些方法。

I didn't face this problem when I run this class as a separate program. Suppose there is 10 directory, i am able to traverse first 5 directory , the exception got randomly while traversing the 6 to 10 directory.

这表明了几种可能性:

• 也许您的请求导致临时过载，并导致内部错误。

• 也许您的请求导致了暂时的过载，并且服务器正在响应 500 个响应以导致您放慢速度。 (在这种情况下，503 将是更合适的响应。)

• 也许此响应是一种旨在阻止网络抓取工具的行为!!

• 也许有一个负载均衡器向多个服务器发送请求，而其中一个(当前)无法正常工作。