Run Java Console Application

Table of Contents

Install Java to VPS
Upload Application to VPS
Aссess Application via SSH
Check Application Operability

In the current tutorial we’ll overview how to install a sample of Java console application to your СentOS virtual private server and check its operability. For that, you’ll need to execute the following operations:

install Java
upload application
access application via SSH
check app operability

Install Java to VPS #

In order to install Java to your VPS container, carry out the next steps, while being connected over SSH protocol by means of CirrusGrid SSH Gate or public IP.

1. Enter the following command to initiate Java package download.

wget {utility_address}

Where {utility_address} is a link to the required Java download source.

Note: The appropriate AuthParam parameter should be specified in the URL, which indicates that you’ve accepted the Oracle licence agreement and can freely download software.

2. Next, execute the command below to unpack the previously downloaded Java rpm package.

rpm -ivh {java_rpm_package}

Where {java_rpm_package} is downloaded Java package with AuthParam parameter indicated.

3. And now let’s check, whether everything is properly set up by inquiring the installed Java version.

java -version

Great! Java is successfully installed, so let’s move further to the application uploading.

Upload Application to VPS #

Prepare your Java application to be uploaded to VPS container. You may use the following example, that will listen the specified port for connections:

import java.io.IOException;  
import java.io.ObjectOutputStream;  
import java.net.InetAddress;  
import java.net.ServerSocket;  
import java.net.Socket;  
import java.util.Date;  
import java.util.logging.Level;  
import java.util.logging.Logger;  
    
public class VdsSocket {  
     
   public static void main(String[] args) {  
      try {  
           int port = 7777;  
           InetAddress thisIp = null;  
           ServerSocket ss = new ServerSocket(port);  
    
           System.out.println  ("**********************************************************************");  
           System.out.println("Socket Listener listens port: " + port);  
           System.out.println("**********************************************************************");  
    
           while (true) {  
               Socket s = ss.accept();  
               String address = s.getRemoteSocketAddress().toString();  
               System.out.println("new client has been detected:");  
               System.out.println("Socket. Remote Address: " + address);  
    
               ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());  
                   
               oos.writeObject("Request time: "+ new Date());  
               oos.writeObject("Socket. Remote Address: " + address);  
           }  
       } catch (IOException ex) {  
       }  
   }  
}

Once your application is ready, you need to pack it into a .jar archive and upload it to VPS container via preferred file transfer client. In our example, we’ll upload vdssocket.jar file by means of WinSCP tool. For that, let’s perform the following steps.

1. Access WinSCP client and connect to your VPS container using credentials received via email upon server installation:

Host name – attached Public IP address
User name – login (i.e. root)
Password – received password

Click on the Login button to initiate connection setup.

2. Once connected to your VPS node, navigate to the home directory and create a new standalone_java context inside. Then drag the required .jar file with your application and drop it into the newly created folder.