无法在Android中连接到FTP

Question

I've checked the other answers and they didn't help me with this error. Maybe I'm doing something else wrong.

Here's my code:

    void uploadPic() throws FileNotFoundException
{
    FileInputStream fis = new FileInputStream(path);
    FTPClient con = new FTPClient();
    int bytesAvailable;
    try
    {
        con.connect("ftp://ftp.drivehq.com/");
        Toast.makeText(this, "Connected to FTP", Toast.LENGTH_SHORT).show();
        if (con.login("x", "x"))
        {
            Toast.makeText(this, "Logged in", Toast.LENGTH_SHORT).show();
            con.enterLocalPassiveMode(); // Active mode doesn't really work on Android
            bytesAvailable = fis.available();
            byte[] barray = new byte[bytesAvailable];
            fis.read(barray);
            ByteArrayInputStream in = new ByteArrayInputStream(barray);
            boolean result = con.storeFile("/CameraUpload.jpg", in);
            in.close();
            if (result) Log.v("Upload Result", "Succeeded");
        }
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
}

I've added INTERNET permission to my project. The logcat shows these errors:

android.os.NetworkOnMainThreadException
W/System.err(17531):    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
W/System.err(17531):    at java.net.InetAddress.lookupHostByName(InetAddress.java:391

I'm connected to the internet via Wifi.

Answer 1

That exception seems to be thrown when you try to perform network operations (such as FTP) from your main thread. This is not allowed for performance reasons (so that the application doesn't appear to lock up to the user, when performing an action which may take a while). Assuming you are using Honeycomb or higher, you would need to move the code that makes the connection into its own child thread.

http://developer.android.com/reference/android/os/NetworkOnMainThreadException.html

http://developer.android.com/guide/practices/design/responsiveness.html

Answer 2

Most likely, this error means that your device cannot resolve ftp.drivehq.com to its IP address. I can't say for sure because you only pasted part of the error log. Make sure you have network connection and that your DNS is working correctly. See if you can connect to this same site via android browser, for example.