Connect using SSH to a server through another server in Java

Question

Currently we have 2 Unix servers A and B. To connect to B server, initially we used to first connect server A and then we will login to JumpHost B using SSH at the Unix prompt.

Now I am working on a simple tool in Java which has to download the files from server B.

In the sample code I got from the link below , if I pass the host details of B server, the host connection is failing.

When I pass the host details of A server the connection is success and able to download the files present in server A.

I need pointers on how to connect to server A and then server B through Java and download files from server B.

SSH Connection Java

score 0 · Answer 1 · answered Dec 19 '16 at 12:41

0

You can use the overthere library. First import the dependency:

<dependency>
    <groupId>com.xebialabs.overthere</groupId>
    <artifactId>overthere</artifactId>
    <version>4.4.2</version>
</dependency>

... and then connect to your severs (A, B, etc):

ConnectionOptions options = new ConnectionOptions();
options.set(ConnectionOptions.PASSWORD, passwd);
options.set(ConnectionOptions.CONNECTION_TIMEOUT_MILLIS, connectionTimeout);
options.set(ConnectionOptions.USERNAME, login);
options.set(ConnectionOptions.ADDRESS, host);
options.set(ConnectionOptions.OPERATING_SYSTEM, OperatingSystemFamily.UNIX);
options.set(SshConnectionBuilder.CONNECTION_TYPE, SshConnectionType.SCP);
OverthereConnection connection = Overthere.getConnection(SshConnectionBuilder.SSH_PROTOCOL, options);

answered Dec 19 '16 at 12:41

Boni García

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is it not possible to achieve multiple SSH Connections through JSch? – Nagendra Vummadi Dec 21 '16 at 09:32
It is possible. Simply repeat the snippet before for each SSH connection you need. – Boni García Dec 21 '16 at 09:35
Multiple jumphost connection can be achieved through jsch setportforwarding method. – Nagendra Vummadi Apr 01 '17 at 00:36

score 0 · Answer 2 · answered Mar 30 '17 at 08:59

What you're actually looking for is what is called in Overthere a Jumpstation.

You want to connect like this: client -> Server A -> Server B

Using overthere you can setup that connection as follows:

ConnectionOptions jumpStationOptions = new ConnectionOptions();
jumpStationOptions.set(ConnectionOptions.ADDRESS, "Server A");
jumpStationOptions.set(ConnectionOptions.USERNAME, "Username A");
jumpStationOptions.set(ConnectionOptions.PASSWORD, "Password A");
jumpStationOptions.set(ConnectionOptions.PROTOCOL, "ssh-jumpstation");
jumpStationOptions.set(ConnectionOptions.OPERATING_SYSTEM, OperatingSystemFamily.UNIX);
ConnectionOptions options = new ConnectionOptions();
options.set(ConnectionOptions.PASSWORD, "Password B");
options.set(ConnectionOptions.USERNAME, "Username B");
options.set(ConnectionOptions.ADDRESS, "Server B");
options.set(ConnectionOptions.OPERATING_SYSTEM, OperatingSystemFamily.UNIX);
options.set(SshConnectionBuilder.CONNECTION_TYPE, SshConnectionType.SCP);
options.set(ConnectionOptions.JUMPSTATION, jumpStationOptions);
OverthereConnection connection = Overthere.getConnection(SshConnectionBuilder.SSH_PROTOCOL, options);

This setup will configure "Server A" to be used as a jumpstation to reach "Server B".

Connect using SSH to a server through another server in Java

2 Answers2