How to read files from SFTP client without JSch

Question

I'm trying to read a couple of files from SecureFTP client for run a daily report task:

The file contents from both the files(.bck file format) looks like this in each line

|00000001|FirstName|LastName|Active|0001|00000000|
|00000002|FirstName|LastName|Incctive|0002|00000001|
|00000003|FirstName|LastName|Active|0003|00020002|

So far, I have successfully made the connection and able to read the file names but unable to read the file contents:

  import net.schmizz.sshj.SSHClient;
  import net.schmizz.sshj.sftp.SFTPClient;
  import net.schmizz.sshj.transport.verification.PromiscuousVerifier;
  import net.schmizz.sshj.sftp.RemoteFile.RemoteFileInputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.time.LocalDate;
  import java.time.format.DateTimeFormatter;
  import java.util.ArrayList;
  import java.util.List;
  import org.apache.commons.io.IOUtils;

  SSHClient ssh = new SSHClient();
  ssh.addHostKeyVerifier(new PromiscuousVerifier());

  try {
    ssh.connect("ServerName");
    ssh.authPassword("username", "password");

    SFTPClient sftp = ssh.newSFTPClient();
    List fileContentsList = new ArrayList();

    try {
      List files = sftp.ls("/");
      LocalDate yesterday = LocalDate.now().minusDays(1);
      DateTimeFormatter formatter = DateTimeFormatter.ofPattern("yyyyMMdd");
      boolean usFileFound = false;
      boolean caFileFound = false;

      for (file : files) {
        String fileName = file.getName();

        if (!file.isDirectory()) {
          if (fileName.contains("SAPHR_POS_CAEEMD_") && fileName.contains(yesterday.format(formatter)) && !caFileFound) {
            RemoteFile remoteFile = sftp.open(fileName); // Obtain the RemoteFile handle
            InputStream inputStream = new RemoteFileInputStream(remoteFile); // Get the input stream
            //List lines = Arrays.asList(fileContents.split("\n"));
            String fileContents = IOUtils.toString(inputStream, "UTF-8"); // Read contents as a string
            fileContentsList.add(fileContents); // Add the contents as string to the list
            caFileFound = true;
            remoteFile.close();

          } else if (fileName.contains("SAPHR_POS_USEEMD_") && fileName.contains(yesterday.format(formatter)) && !usFileFound) {
            RemoteFile remoteFile = sftp.open(fileName); 
            InputStream inputStream = new RemoteFileInputStream(remoteFile);
            String fileContents = IOUtils.toString(inputStream, "UTF-8");
            fileContentsList.add(fileContents);
            usFileFound = true;
            remoteFile.close();
          }
          if (caFileFound && usFileFound) {
            break; // Stop after both files found
          }
        }
      }
    } finally {
      sftp.close();
    }

    String result = String.join("\n", fileContentsList);
    return result;
  } finally {
    try {
      ssh.disconnect();
    } catch (IOException e) {
      e.printStackTrace();
    }
  }

The output from current code:

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE List PUBLIC "sailpoint.dtd" "sailpoint.dtd">
<List>
  <String>SAPHR_POS_CAEEMD_20230722.txt1690068889231.bck</String>
  <String>SAPHR_POS_USEEMD_20230722.txt1690068894774.bck</String>
</List>

The error received while trying to perform the commented lines in above code:

Exception running rule: BeanShell script error: bsh.EvalError: Sourced file: inline evaluation of: 
Author: user007 Date: 16-07-2023     Details: ********* . . . '' : Typed variable declaration : Error in method invocation: Method getInputStream(java.lang.String) not found in class'net.schmizz.sshj.sftp.SFTPClient' :
at Line: 48 : in file: inline evaluation of:
``   /*********** Author: user007  Date: 16-07-2023  Details: ********* . . . '' : sftp .getInputStream ( fileName )   BSF info: usersReport
at line: 0 column: columnNo

I don't see where this code outputs anything at all, let alone this XML. — user207421, Jul 23 '23 at 06:56
1) You have mangled your source code. `&&` is not valid Java. 2) `return fileContentsList;` is not outputting XML. It is returning a list that apparently contains file names. — Stephen C, Jul 23 '23 at 07:35
@StephenC updated the code, its not mangled its just the format in my app on how to represent special characters, its a bean shell script --> https://beanshell.github.io/manual/contents.html And yes, its returning the filenames in a List, but what I was looking is a way to output the file contents instead of file names — D C, Jul 23 '23 at 07:42
@g00se yes xml has nothing to do with it, the out was a list of filenames, I was looking on how to get the file contents — D C, Jul 23 '23 at 11:48
@DC - Advice: if something has nothing to do with the task at hand **don't put it in the question**. It only serves to **confuse** people. Likewise, with tags. AFAIK, `[sailpoint]` is not relevant to your question at all. — Stephen C, Jul 23 '23 at 11:51
If you want to get files, you should be using [this](https://www.javadoc.io/static/com.hierynomus/sshj/0.23.0/net/schmizz/sshj/sftp/SFTPClient.html#get-java.lang.String-java.lang.String-) — g00se, Jul 23 '23 at 13:22
@DC `return fileContentsList` does not constitute outputting anything, let alone XML. — user207421, Jul 24 '23 at 05:31

Stephen C · Accepted Answer · 2023-07-23T12:12:42.037

I think that the problem is that you are using the APIs incorrectly.

If you look at the examples for SFTPClient, they don't use a method called getretrieveFileStream. In fact, there isn't a method in the API whose name remotely resembles that. Calling non-existent methods is never going to work.

I recommend that you look at the examples for yourself and see if they do what you want. And look at the javadocs for the APIs. For example:

I suspect the pattern for extracting the contents of a file will be something like this:

Obtain an SFTPClient.
Call open on the client to obtain a RemoteFile handle for the file you want to read.
Using that handle as the outer class context, invoke the RemoteFileInputStream no-args constructor to get an input stream.
Read from the input stream in the normal way
Close the stream and the handle

Solved it found the right method, thanks for your inputs :) I have updated the code — D C, Jul 23 '23 at 17:46

How to read files from SFTP client without JSch

1 Answers1