Getting a remote System timestamp using Jsch Java API

Question

I am using the excellent com.jcraft.jsch API to connect to a remote server using the following code.

    JSch ssh = new JSch();
    JSch.setConfig(FileTransferConstants.STRICT_HOST_KEY_CHECKING, FileTransferConstants.NO);
    session = ssh.getSession(user, host, port);
    session.setPassword(password);
    session.connect();
    channel = session.openChannel(FileTransferConstants.SFTP);
    channel.connect();
    ChannelSftp sftp = (ChannelSftp) channel;

Once connected, I then use SFTP to download some log files. This works very well.

Once the files have been retrieved, I interrogate them locally based on the timestamps of the log entries - I am looking for entries within a specific time window.

Up until now it has caused me no problem because my local system timestamp has been very similar to the remote timestamp. But recently my tests started failing due to there now being a 5 minute discrepancy between my local timestamp and that on the remote server.

So my question is, is there is a simple way of getting the remote system time using Jsch? If so, I would simply retrieve this and use it in my tests instead of my local system time. Then hopefully the discrepancy issue should immediately go away!

Thank you for reading and considering my question.

You could try to execute `date +%m%d%Y%H%M%S` (or ay other format you need) command on the remote server and read output. Check this question on how execute and read output https://stackoverflow.com/questions/11532890/running-linux-commands-on-java-through-jsch — Ivan, Feb 26 '18 at 17:05
Excellent suggestion Ivan. This seems to do the job just great! — Jon H, Feb 27 '18 at 11:07

score 2 · Accepted Answer · edited Dec 15 '18 at 22:28

Adding working suggestion from comment as an answer if anybody else faces the same problem.

ChannelExec channelExec = (ChannelExec)session.openChannel("exec");
InputStream in = channelExec.getInputStream();
channelExec.setCommand("date +%m%d%Y%H%M%S"); //Date format could be changed to your desired format
channelExec.connect();

BufferedReader reader = new BufferedReader(new InputStreamReader(in));
String line;
int index = 0;
while ((line = reader.readLine()) != null) {
   System.out.println(++index + " : " + line);
}

channelExec.disconnect();

Getting a remote System timestamp using Jsch Java API

1 Answers1