Getting a specific file from SFTP

This is not an endorsed method. They seem to consider adding support for this use case in standard SFTP Adapter.

Setting StrictHostKeyChecking to no means someone controlling the domain/ip address can change the server without you noticing. That is the reason known_hosts file exists.

You should download jsch.jar from http://www.jcraft.com/jsch/ and add it to Flow using: Flow->Resources->Add->Archive

Groovy IDE notice
You can't test external Jar archives with GroovyIDE at the moment.

Script

Try it on

import com.sap.gateway.ip.core.customdev.util.Message;
import java.util.HashMap;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;

import com.jcraft.jsch.Channel;
import com.jcraft.jsch.ChannelSftp;
import com.jcraft.jsch.JSch;
import com.jcraft.jsch.JSchException;
import com.jcraft.jsch.Session;
import com.jcraft.jsch.SftpException;
import com.sap.it.api.securestore.SecureStoreService;
import com.sap.it.api.securestore.UserCredential;
import com.sap.it.api.ITApiFactory;

import java.util.HashMap;
def Message processData(Message message) {

    //Properties
    map = message.getProperties();

    def sftp_hostname = map.get("sftp_hostname")
    def sftp_port = map.get("sftp_port")
    def sftp_credential = map.get("sftp_credential");
    def sftp_filename = map.get("sftp_filename");

    def secureStorageService =  ITApiFactory.getApi(SecureStoreService.class, null);
    def credential = secureStorageService.getUserCredential(sftp_credential);

    if (credential == null){
    // TODO
    }

    String sftp_username = credential.getUsername();
    String sftp_password =  new String(credential.getPassword());

    String encodedString = getFileContentFromSFTP(sftp_hostname,sftp_port,sftp_username,sftp_password,sftp_filename)
    message.setBody(encodedString);

    return message;
}

def String getFileContentFromSFTP(sftp_hostname,sftp_port,sftp_username,sftp_password,sftp_filename){
        JSch jsch = new JSch();
    Session session = null;
    try {
        session = jsch.getSession(sftp_username, sftp_hostname, sftp_port as Integer);
        session.setConfig("StrictHostKeyChecking", "no");
        session.setPassword(sftp_password);
        session.connect(10000);

        Channel channel = session.openChannel("sftp");
        channel.connect();
        ChannelSftp sftpChannel = (ChannelSftp) channel;

        InputStream stream = sftpChannel.get(sftp_filename);

        def bytes = convertInputStreamToBytes(stream)

        def encodedString = Base64.getEncoder().encodeToString(bytes)

        return encodedString

    } catch (Exception e) {
        throw e;
    } finally {
        sftpChannel.exit();
        session.disconnect();
    }
}

def byte[] convertInputStreamToBytes(InputStream inputStream){

    ByteArrayOutputStream result = new ByteArrayOutputStream();
    byte[] buffer = new byte[1024];
    int length;
    while ((length = inputStream.read(buffer)) != -1) {
        result.write(buffer, 0, length);
    }

    return result.toByteArray()
}

Input Properties