Client.java

package ftp;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;
import java.util.Arrays;
import java.util.List;
import java.util.Scanner;
import java.util.stream.Collectors;
import java.util.stream.Stream;

public class Client {

    int cport;
    int timeout;

    private static SocketChannel client;
    private static ByteBuffer buffer;
    private static Client instance;


    /**
     * @desc constructs a client
     * @param cport controller port to use
     * @param timeout timeout (ms)
     */
    public Client(int cport, int timeout) {
        this.cport = cport;
        this.timeout = timeout;

        try {
            client = SocketChannel.open(new InetSocketAddress(cport));
            buffer = ByteBuffer.allocate(256);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }


    public String sendMessage(String msg) {
        buffer = ByteBuffer.wrap(msg.getBytes());
        String response = null;
        try {
            client.write(buffer);
            buffer.clear();
            client.read(buffer);
            response = new String(buffer.array()).trim();
            System.out.println("response=" + response);
            buffer.clear();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return response;

    }


    public static void main(String args[]) {
        Stream<String> str = Arrays.stream(args);

        List<Integer> intArgs = str.map(x -> {return Integer.parseInt(x);})
                .collect(Collectors.toList());

        instance = new Client(intArgs.get(0),intArgs.get(1));

        Scanner scanner = new Scanner(System.in);
        String command = "";

        while (!command.equals("quit")) {

            System.out.println("Enter Command:");
            command = scanner.nextLine();

            String response = instance.sendMessage(command);

            System.out.println(response);

        }
    }

}