使用Apache FTPClient 3.1和FTP.BINARY_FILE_TYPE上传后，JAVA 6和损坏的文件

Question

I'm really going bonkers on this.

I'm writing a small Java (must be SDK 6) tool using the commons-net-3.1.jar library to upload a bunch of files to another bunch of servers simultaneously. I will use it with .jpg images mostly. I set the connection to BINARY_FILE_TYPE before anyone ask :)

When I try and run it, everything goes smooth but sometimes, after uploading the images, they have "small lines" on them, like if the file had been corrupted on its way.

This little piece of code is the one who does all the work. Any clues about how should I manage the first catches when the os.write fails in order to keep the file uploading right?

try {
    InputStream is = new FileInputStream(rutaFichero);
    OutputStream os = ftp.storeFileStream(nombreFichero);
    byte buf[] = new byte[8192];
    bytesRead = is.read(buf);

    while ((bytesRead = is.read(buf)) != -1) {
        try {
            os.write(buf, 0, bytesRead);
        } catch (IOException ioe) {
        } catch (NullPointerException npe) {
        }
    }

    is.close();
    try {
        os.close();
        completado = ftp.completePendingCommand();
        if (completado) {
    } catch (NullPointerException npe) {}
}

Out of curiosity, I thought it could be just bad conditions on the line so I checked the sizes of files after transfering for some days and... none of them matched! WTF!?

Answer 1

You have a bug in the first line here:

bytesRead = is.read(buf);

while ((bytesRead = is.read(buf)) != -1) {
    try {
        os.write(buf, 0, bytesRead);
    } catch (IOException ioe) {
    } catch (NullPointerException npe) {
    }
}

You never write the first buf contents. You just read them and then read subsequent chunk in while loop. Remove the first is.read() and you'll be fine.

It's another reason to avoid such tedious code and go for utility methods such as IOUtils.copy() :

InputStream is = new FileInputStream(rutaFichero);
OutputStream os = ftp.storeFileStream(nombreFichero);
IOUtils.copy(is, os);
is.close();
os.close();

Answer 2

当一些人给我发电子邮件给我一个关于确保在登录后将模式类型设置为二进制的建议时，问题就解决了。