使用 Apache Common Net 从 FTP 下载到设备时损坏的 PDF 文件

Question

我正在尝试将文件从 FileZilla 服务器下载到 Android 设备。 一切似乎都正确，FTP 连接、登录、文件存在并且下载响应正常。 但是当我转到 Android 设备中的文件时，它只有 64KB 的大小，它一定是，并且由于已损坏而无法打开...我尝试过另一个 49KB 的文件并下载了 48KB，它是也腐败了。我正在使用 Adobe Acrobat Reader 和 QuickOffice 打开文件。

String usuarioLogin = params[0];

FTPClient ftp = null;
String LOG_TAG = "FTP";
ftp = new FTPClient();
String server = params[0];
int portNumber = Integer.parseInt(params[1]);
String user = params[2];
String password = params[3];
String filename = params[4];
File localFile = UtilsVictor.crearFichero(params[5]);

ftp.connect(server, portNumber);
Log.d(LOG_TAG, "Connected. Reply: " + ftp.getReplyString());
ftp.enterLocalPassiveMode();

ftp.login(user, password);
Log.d(LOG_TAG, "Logged in");
ftp.setFileType(FTP.LOCAL_FILE_TYPE);
Log.d(LOG_TAG, "Downloading");

OutputStream outputStream = null;
boolean success = false;
outputStream = new BufferedOutputStream(new FileOutputStream(
        localFile));
success = ftp.retrieveFile(filename, outputStream);

if(success) {
    Log.d(LOG_TAG, "success!!");
} else{
    Log.d(LOG_TAG, "NOOOOT success!!");
}

FileZilla 服务器的日志：

(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> Connected on port 50000, sending welcome message...
(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> 220-FileZilla Server 0.9.60 beta
(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> 220-written by Tim Kosse ([email protected])
(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> 220 Please visit https://filezilla-project.org/
(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> USER VICTOR
(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> 331 Password required for victor
(000019)13/01/2018 17:13:14 - (not logged in) (192.168.1.38)> PASS ****
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> 230 Logged on
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> TYPE I
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> 200 Type set to I
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> PASV
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> 227 Entering Passive Mode (192,168,1,41,125,49)
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> RETR /Informes/572760344M/aaa.pdf
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> 150 Opening data channel for file download from server of "/Informes/572760344M/aaa.pdf"
(000019)13/01/2018 17:13:14 - victor (192.168.1.38)> 226 Successfully transferred "/Informes/572760344M/aaa.pdf"
(000019)13/01/2018 17:13:48 - victor (192.168.1.38)> disconnected.

问题出在哪里？

Answer 1

你不见了

outputStream.close();

---

无需完全重写您的代码。您的新代码只是不必要地重新实现

FTPClient.retrieveFile

内部所做的事情。

即使您选择使用

FTPClient.retrieveFileStream

，也要使用

Util.copyStream

）而不是自己实现复制循环。

Answer 2

我发现错误了，是在存储过程中：

更改此：

OutputStream outputStream = null;
            boolean success = false;
            outputStream = new BufferedOutputStream(new FileOutputStream(
                    localFile));
            success = ftp.retrieveFile(filename, outputStream);

            if(success) {
                Log.d(LOG_TAG, "success!!");
            } else{
                Log.d(LOG_TAG, "NOOOOT success!!");
            }

对此：

 InputStream myFileStream = null;
            myFileStream = ftp.retrieveFileStream(filename);
            File fileToWrite = new File(params[5]);
            java.io.FileOutputStream fos = new java.io.FileOutputStream("/storage/emulated/0/Download/"+fileToWrite);
            java.io.BufferedOutputStream bout = new BufferedOutputStream(fos,1024);
            byte data[] = new byte[1024];
            int x =0;
            while((x=myFileStream.read(data,0,1024))>=0){
                bout.write(data,0,x);
            }
            bout.close();
            myFileStream.close();
            res = ftp.getReplyCode();

完美运行！