HDLC Simulator

Client.java

package devoir.client;

import devoir.hdlc.Trame;
import devoir.hdlc.specific.ATrame;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.time.Instant;
import java.time.LocalDateTime;
import java.time.ZoneId;


public abstract class Client {
    private Socket clientSocket;
    private PrintWriter out;
    private BufferedReader in;
    private EnumClient type;

    public Client(EnumClient type) {
        this.type = type;
    }

    public String getType() {
        return this.type.getType();
    }

    public void startConnection(String ip, int port) {
        try {
            System.out.println(getType() + " has connected to IP " + ip
                    + " on port " + port);
            clientSocket = new Socket(ip, port);
            out = new PrintWriter(clientSocket.getOutputStream(), true);
            in  = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));

        } catch (IOException e) {
            // todo: close connection here in case of error?
            e.printStackTrace();
        }
    }


    /**
     * Using "System.out.println()" will print in the ClientMain shell.
     *
     * Using "out.println()" will print in the ServerMain shell. The Server
     * will receive that info through it's "in.readLine()" method.
     * @param trame
     * @return The response
     */
    public String sendFrame(Trame trame) {

        // outward-bound frame
        frameStamp(true, trame);
        out.println(trame);

        // collecting the response
        String response = null;
        try {
            response = in.readLine();
            // todo: translate into a Trame and return that

            // todo: next 2 lines are temporary, for testing purposes: will be removed eventually
            ATrame aTrame = new ATrame(trame.getNumAsInt());
            frameStamp(false, aTrame);

        } catch (IOException e) {
            e.printStackTrace();
        }

        return response;
    }

    /**
     * Identify messages in the shell to let user know what's happening
     * behind the scene.
     * @param isGoingOut 'true' if frame is sent to 'out'
     *                   'false' if frame is receive through 'in'
     * @param trame used to extract relevant information "(Type,Num)"
     */
    public void frameStamp(boolean isGoingOut, Trame trame) {
        // direction
        String direction = isGoingOut ? "OUT" : "IN ";

        // timestamp
        String now = LocalDateTime.ofInstant(Instant.now(), ZoneId.systemDefault()).toString();
        String hours = now.substring(11,24);

        // frame type
        String frame = "(" + trame.getType() + "," + trame.getNumAsInt() + ")";

        // print the actual "frame stamp"
        System.out.println("[ " + direction + " @ " + hours + " ]    " + frame + "    " + trame.toString());
    }

    public void stopConnection() {
        // lazy try-catch :D
        try {
            in.close();
            out.close();
            clientSocket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}