java - 为什么我的 InputStream 在 Android 中无法工作？

Question

我正在为我最喜欢的图片库软件编写一个 Android 图像文件 uploader ，它使用 FTP。 我已经开始使用 Apache-Commons Net FTP 作为我的 ftp 库，基于 past stack overflow questions 。就像这样:

FTPClient ftp = new FTPClient();
try{
  ftp.connect(host);
  Log.i(TAG,"we connected");
  if(!ftp.login(user,pass)){
    ftp.logout();
    //TODO: alert user it didn't happen
    return;
  }    
  String replyStatus = ftp.getStatus();
  Log.i(TAG,replyStatus);
  int replyCode = ftp.getReplyCode();
  if (!FTPReply.isPositiveCompletion(replyCode))
  {    
    ftp.disconnect();
    //TODO: alert user it didn't happen
    return;
  }    
  Log.i(TAG,"we logged in");
  ftp.changeWorkingDirectory(path);
  ftp.setFileType(ftp.BINARY_FILE_TYPE);
  for(int i = 0; i < contentUris.size(); i++){
    Log.i(TAG,"uploading new file");
    Uri stream = (Uri) contentUris.get(i);
    //InputStream in = openFileInput(getRealPathFromURI(stream));
    InputStream in =this.getContentResolver().openInputStream(stream);
    BufferedInputStream buffIn=null;
    buffIn=new BufferedInputStream(in);

    ftp.setFileType(ftp.BINARY_FILE_TYPE);
    boolean Store = ftp.storeFile("test.jpg", buffIn);
    Log.i(TAG, "uploaded test");
  }      
  ftp.disconnect();
}      
catch(Exception ex){
  //do something wise and smart and useful
}

我在日志中看到我正在登录，我可以更改目录，并且当我上传时，我会在我的目录中获得一个 test.jpg，但大小为 0 字节。

什么给了？我没有打开输入流吗？我该如何正确地做到这一点？

如果我没有提供足够的详细信息，请告诉我 - full code is also available on github

Answer 1

看起来问题是您无法建立主动 ftp 连接，您必须使用被动模式。因此将顶部更改为:ftpClient.enterLocalPassiveMode();

FTPClient ftp = new FTPClient();
try{
  ftp.connect(host);
  ftp.enterLocalPassiveMode();
  Log.i(TAG,"we connected");
  if(!ftp.login(user,pass)){
    ftp.logout();
    //TODO: alert user it didn't happen
    return;
  }
  String replyStatus = ftp.getStatus();
  Log.i(TAG,replyStatus);
  int replyCode = ftp.getReplyCode();
  if (!FTPReply.isPositiveCompletion(replyCode))
  {
    ftp.disconnect();
    //TODO: alert user it didn't happen
    return;
  }

  Log.i(TAG,"we logged in");
  ftp.changeWorkingDirectory(path);
  ftp.setFileType(ftp.BINARY_FILE_TYPE);
  for(int i = 0; i < contentUris.size(); i++){
    Log.i(TAG,"uploading new file");
    Uri stream = (Uri) contentUris.get(i);
    String filePath = getRealPathFromURI(stream);
    InputStream in = new FileInputStream(filePath);
    ftp.setFileType(ftp.BINARY_FILE_TYPE);

    boolean Store = ftp.storeFile("test.jpg", in);
    Log.i(TAG, "uploaded test");
  }


  ftp.disconnect();
}
catch(Exception ex){
  //TODO: properly handle exception
  //Log.i(TAG,ex);
  //TODO:Alert the user this failed
}