Java

Hello everyone, I need to develop a Java software that takes a .PDF file as input and signs it in PAdeS format using a CNS or a SmartCard containing one's own PIN-protected certificate.
I've been trying to understand how to do this for several days, but I can't figure out the correct workflow to follow. I also don't understand how to interact with the SmartCard, it's not clear to me whether I need to extract the certificates to load them into my Java application, or if it's possible to proceed simply by using the reader driver to access the card. In both cases, I don't know where to start.
Do you have any advice or code snippets/classes to share? Thanks.

Given an array arr of size N. Your task is to determine that if by reversing any one subarray can the given array be sorted or not.

You have to complete solve function which consists of arr array of size N as inputs and you have to return boolean answer as output.

Input Format
The first line of input contains a single integer N.

The second line of input contains N space seperated integers.

Output Format
Return true, if by reversing any one subarray sorted array can be formed as else false , "Yes" or "No" will be taken care by driver code.

public static void main(String[] args) throws Exception {
    Thread thread = new Thread(new Runnable() {
        @Override
        public void run() {
            try {
                ServerSocket server = new ServerSocket(port);
                Socket socket = server.accept();
                System.out.println(new ObjectInputStream(socket.getInputStream()).readObject());
                socket.close();
                server.close();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (ClassNotFoundException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    });
    thread.start();

    Socket socket = new Socket("IP_ADDRESS", port);
    new ObjectOutputStream(socket.getOutputStream()).writeObject("Test");
    socket.close();
}