Android FTP拒绝连接到主机

Question

I have been trying to build an application which captures a few data items from the user and then proceeds to compress it all into a zip file and FTP over to a server. The compression part works as a charm and i am sure that the FTP would too, except that the program refuses to connect to the host.

I have tried all permutations and combinations to solving this and have been unable to realise what the problem is. I have included the apache commons net libraries and have been able to pin point the error to the connection part. Most of the code has been commented out so as to allow only the one part to be used.

My code is as `package com.example.gis;

import java.io.FileInputStream;

import org.apache.commons.net.ftp.FTPClient;
import org.apache.commons.net.ftp.FTPReply;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.Toast;


public class FTP extends Activity {

public static FTPClient mFTPClient = null;
public String TAG="1234";
public static String a;
public static String b;
//public static int abc=FTP.BINARY_FILE_TYPE; 
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.ftp);

Bundle extras = getIntent().getExtras();
boolean m=ftpConnect("ftp://xxxxxxxxxx.xxx", "username omitted", "password omitted", 21);
if(m==true)
{
    Toast.makeText(this,"FTP Login" , Toast.LENGTH_LONG).show();

a=extras.getString("path");
b=extras.getString("name");
ftpUpload("a", "b", "/test/");
ftpDisconnect();

}
else
    Toast.makeText(this,"Failure to connect" , Toast.LENGTH_LONG).show();
}



public boolean ftpConnect(String host, String username,
        String password, int port)
{
    mFTPClient=new FTPClient();

try {

// connecting to the host
mFTPClient.connect(host, port);

// now check the reply code, if positive mean connection success
if (FTPReply.isPositiveCompletion(mFTPClient.getReplyCode())) {
// login using username & password
boolean status = mFTPClient.login(username, password);
Toast.makeText(this,"Connected as status ="+status, Toast.LENGTH_LONG).show();
/* Set File Transfer Mode
*
* To avoid corruption issue you must specified a correct
* transfer mode, such as ASCII_FILE_TYPE, BINARY_FILE_TYPE,
* EBCDIC_FILE_TYPE .etc. Here, I use BINARY_FILE_TYPE
* for transferring text, image, and compressed files.
*/
mFTPClient.setFileType(abc);

mFTPClient.enterLocalPassiveMode();

return status;
}
} catch(Exception e) {
Log.d(TAG, "Error: could not connect to host " + host );
}

return false;
}

public boolean ftpDisconnect()
{
    try {
        mFTPClient.logout();
        mFTPClient.disconnect();
        return true;
    } catch (Exception e) {
        Log.d(TAG, "Error occurred while disconnecting from ftp server.");
    }

    return false;
}


/**
 * mFTPClient: FTP client connection object (see FTP connection example)
 * srcFilePath: source file path in sdcard
 * desFileName: file name to be stored in FTP server
 * desDirectory: directory path where the file should be upload to
 */
public boolean ftpUpload(String srcFilePath, String desFileName,
                         String desDirectory)
{
    boolean status = false;
    try {
        FileInputStream srcFileStream = new FileInputStream(srcFilePath);

        // change working directory to the destination directory
        if (ftpChangeDirectory(desDirectory)) {
            status = mFTPClient.storeFile(desFileName, srcFileStream);
        }

        srcFileStream.close();
        return status;
    } catch (Exception e) {
        Log.d(TAG, "upload failed");
    }

    return status;
}


}

Have been raking my head over this for quite sometime now.

Answer 1

boolean m=ftpConnect("ftp://xxxxxxxxxx.xxx", ...

You are specifying a protocol with ftp://. You are not supposed to do that. You only have to specify the server (or host) like "ftp.mycompany.com".

Moreover if you try to connect then you have to catch SocketException, UnknownHostException and IOException separately. By printing the stacktrace you would know what caused the error. I see you are not doing that.

As a last remark I see that you do this internet acces on the main thread. I know that that is possible for ftp ( why for ftp and not for http?) but you could better use a thread or an asynctask.