Android + JCraft JSch SFTP上传-“ org.apache.commons.vfs2.FileSystemException：无法在以下位置连接到SFTP服务器”

Question

I'm trying to send a file by SFTP using JSch from JCraft. I'm getting an exception "org.apache.commons.vfs2.FileSystemException: Could not connect to SFTP server at...". It seems like JSch isn't even tried to send username and password. From the OpenSSH server side (loglevel=DEBUG3) i'm seeing those :

Oct 19 22:20:30 android sshd[10973]: debug3: oom_adjust_restore
Oct 19 22:20:30 android sshd[10973]: debug1: Set /proc/selfoom_score_adj to 0
Oct 19 22:20:30 android sshd[10973]: debug1: rexec start in 4 out 4 newsock 4 pipe 6 sock 7
Oct 19 22:20:30 android sshd[10973]: debug1: inetd sockets after dupping: 3, 3
Oct 19 22:20:30 android sshd[10973]: Connection from 192.168.0.165 port 45653 on 192.168.0.100 port 22
Oct 19 22:20:30 android sshd[10973]: Did not receive identification string from 192.168.0.165 port 45653

There is no problem when trying to copy file using scp from the console. Here is the java class I'm using :

import org.apache.commons.vfs2.FileObject;
import org.apache.commons.vfs2.FileSystemException;
import org.apache.commons.vfs2.FileSystemOptions;
import org.apache.commons.vfs2.Selectors;
import org.apache.commons.vfs2.impl.StandardFileSystemManager;
import org.apache.commons.vfs2.provider.sftp.SftpFileSystemConfigBuilder;

import java.io.File;

public class SftpExample {


    public static void main(String[] args) {
        String hostName = "192.168.0.100";
        String username = "admin";
        String password = "admin";
        String localFilePath = "/storage/emulated/0/file.txt";
        String remoteFilePath = "file.txt";

        upload(hostName, username, password, localFilePath, remoteFilePath);
        exist(hostName, username, password, remoteFilePath);
        download(hostName, username, password, localFilePath, remoteFilePath);
        delete(hostName, username, password, remoteFilePath);
    }
    // Method to upload a file in Remote server
    public static void upload(String hostName, String username,
                              String password, String localFilePath, String remoteFilePath) {

        File file = new File(localFilePath);
        if (!file.exists())
            throw new RuntimeException("Error. Local file not found");

        StandardFileSystemManager manager = new StandardFileSystemManager();

        try {
            manager.init();

            // Create local file object
            FileObject localFile = manager.resolveFile(file.getAbsolutePath());

            // Create remote file object
            FileObject remoteFile = manager.resolveFile(
                    createConnectionString(hostName, username, password,
                            remoteFilePath), createDefaultOptions());

            // Copy local file to sftp server
            remoteFile.copyFrom(localFile, Selectors.SELECT_SELF);

            System.out.println("File upload success");
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            manager.close();
        }
    }
    // Download file function:
    public static void download(String hostName, String username,
                                String password, String localFilePath, String remoteFilePath) {

        StandardFileSystemManager manager = new StandardFileSystemManager();

        try {
            manager.init();

            String downloadFilePath = localFilePath.substring(0,
                    localFilePath.lastIndexOf("."))
                    + "_downlaod_from_sftp"
                    + localFilePath.substring(localFilePath.lastIndexOf("."),
                    localFilePath.length());

            // Create local file object
            FileObject localFile = manager.resolveFile(downloadFilePath);

            // Create remote file object
            FileObject remoteFile = manager.resolveFile(
                    createConnectionString(hostName, username, password,
                            remoteFilePath), createDefaultOptions());

            // Copy local file to sftp server
            localFile.copyFrom(remoteFile, Selectors.SELECT_SELF);

            System.out.println("File download success");
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            manager.close();
        }
    }
    // Delete file in remote system:
    public static void delete(String hostName, String username,
                              String password, String remoteFilePath) {
        StandardFileSystemManager manager = new StandardFileSystemManager();

        try {
            manager.init();

            // Create remote object
            FileObject remoteFile = manager.resolveFile(
                    createConnectionString(hostName, username, password,
                            remoteFilePath), createDefaultOptions());

            if (remoteFile.exists()) {
                remoteFile.delete();
                System.out.println("Delete remote file success");
            }
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            manager.close();
        }
    }
    // Check remote file is exist function:
    public static boolean exist(String hostName, String username,
                                String password, String remoteFilePath) {
        StandardFileSystemManager manager = new StandardFileSystemManager();

        try {
            manager.init();

            // Create remote object
            FileObject remoteFile = manager.resolveFile(
                    createConnectionString(hostName, username, password,
                            remoteFilePath), createDefaultOptions());

            System.out.println("File exist: " + remoteFile.exists());

            return remoteFile.exists();
        } catch (Exception e) {
            throw new RuntimeException(e);
        } finally {
            manager.close();
        }
    }
    // Establishing connection
    public static String createConnectionString(String hostName,
                                                String username, String password, String remoteFilePath) {
        return "sftp://" + username + ":" + password + "@" + hostName + "/" + remoteFilePath;
    }
    //  Method to setup default SFTP config:
    public static FileSystemOptions createDefaultOptions()
            throws FileSystemException {
        // Create SFTP options
        FileSystemOptions opts = new FileSystemOptions();

        // SSH Key checking
        SftpFileSystemConfigBuilder.getInstance().setStrictHostKeyChecking(
                opts, "no");

        // Root directory set to user home
        SftpFileSystemConfigBuilder.getInstance().setUserDirIsRoot(opts, true);

        // Timeout is count by Milliseconds
        SftpFileSystemConfigBuilder.getInstance().setTimeout(opts, 10000);


        return opts;
    }


}

And this is how I execute sftp upload :

SftpExample.upload(hostName,username,password,localFilePath,remoteFilePath);

...I've just managed to connect Android Studio debugger to the process of that app on the phone and I've find out that there are some missing libs. So, I've add :

org.apache.commons.net.ftp
org.apache.commons.httpclient
org.apache.jackrabbit.webdav.client

I was compiling the APK after each lib added and there is a problem with the last one :

Error:Execution failed for task ':app:transformResourcesWithMergeJavaResForDebug'.
> com.android.build.api.transform.TransformException: com.android.builder.packaging.DuplicateFileException: Duplicate files copied in APK META-INF/LICENSE
File1: /home/g/StudioProjects/AndroidProject/app/build/libs/jackrabbit-webdav-2.2.5.jar
File2: /home/g/.gradle/caches/modules-2/files-2.1/org.objenesis/objenesis/2.6/639033469776fd37c08358c6b92a4761feb2af4b/objenesis-2.6.jar

Any one know all dependency libs I will need to install to run the code?

Cheers

Answer 1

After some time, I've started from the beginning and used different solution which I should recommend as it worked out of the box. I've used Zehon which is based on JCraft JSch too. You can get it from :

http://www.zehon.com/downloads.htm

The sample code for using the SFTP works great. You can get it from here :

http://www.zehon.com/SFTP_samples.htm

Also, from the server side, OpenSSH server needs to have those lines in the config file :

KexAlgorithms +diffie-hellman-group1-sha1
KexAlgorithms +diffie-hellman-group-exchange-sha1
Ciphers aes128-cbc,3des-cbc,blowfish-cbc

Happy coding! :)