Riassunti

PARTE Server

Per quanto riguarda il file Main.java:

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

public class Main {
    public static void main(String[] args) {
        JFrame f = new JFrame("Server");
        f.setSize(400,400);
        JPanel p = new JPanel();
        p.setLayout(new GridLayout(2, 1));

        JButton startServer = new JButton("Start server");
        JTextArea area = new JTextArea();

        startServer.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                Server server = new Server(area);
                server.startServer();
                startServer.setEnabled(false);
            }
        });

        p.add(startServer);
        p.add(new JScrollPane(area));
        f.add(p);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
}

Per quanto riguarda il file MessagesHandler.java:

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import javax.swing.JTextArea;

public class MessagesHandler implements Runnable {
    private Socket socket;
    private JTextArea area;

    public MessagesHandler(Socket socket, JTextArea area) {
        this.socket = socket;
        this.area = area;
    }

    @Override
    public void run() {
        try {
            BufferedOutputStream bOut = new BufferedOutputStream(socket.getOutputStream());
            PrintWriter out = new PrintWriter(bOut, true);
            out.println("Welcome!");

            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            while(!Thread.currentThread().isInterrupted()) {
                if(in.ready()) {
                    String line = in.readLine();
                    area.append("Client wrote: " + line + System.lineSeparator());
                    if(line.equals("ciao"))
                        out.println("ciao a te!");
                    else if(line.equals("come stai?"))
                        out.println("bene, tu?");
                }
            }
        } catch (IOException e) {
            area.append("Connection error: " + e.getMessage() + System.lineSeparator());
        }
    }
}

Per quanto riguarda il file Server.java:

import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import javax.swing.JTextArea;

public class Server implements Runnable {
    private JTextArea area;
    private ServerSocket server;
    private ExecutorService executor;

    public Server(JTextArea area) {
        this.area = area;
        executor = Executors.newCachedThreadPool();
    }

    public void startServer() {
        try {
            server = new ServerSocket(8000);
            Thread t = new Thread(this);
            t.start();
        } catch (IOException e) {
            area.append("Error while starting the server: " + e.getMessage() + System.lineSeparator());
        }
    }

    @Override
    public void run() {
        while (!Thread.currentThread().isInterrupted()) {
            try {
                area.append("Waiting for new connections..." + System.lineSeparator());
                Socket socket = server.accept();
                area.append("Client connected." + System.lineSeparator());
                MessagesHandler handler = new MessagesHandler(socket, area);
                executor.submit(handler);
            } catch (IOException e) {
                area.append("Connection error: " + e.getMessage() + System.lineSeparator());
                return;
            }
        }
    }
}

PARTE Client

Per quanto riguarda il file Main.java:

import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;

public class Main {
    public static void main(String[] args) {
        JFrame f = new JFrame("Client");
        f.setSize(400,400);
        JPanel p = new JPanel();
        p.setLayout(new GridLayout(3, 1));

        JButton startServer = new JButton("Send message");
        JTextArea area = new JTextArea();
        area.setEditable(false);
        JTextArea myMessages = new JTextArea();
        Client c = new Client(area);
        c.startClient();
        startServer.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                c.sendMessage(myMessages.getText());
                myMessages.setText("");
            }
        });

        p.add(startServer);
        p.add(new JScrollPane(area));
        p.add(new JScrollPane(myMessages));
        f.add(p);
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.setVisible(true);
    }
}

Per quanto riguarda il file Client.java:

import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import javax.swing.JTextArea;

public class Client implements Runnable {
    private JTextArea area;
    private Socket socket;

    public Client(JTextArea area) { this.area = area; }

    public void startClient() {
        try {
            socket = new Socket("localhost", 8000);
            Thread t = new Thread(this);
            t.start();
        } catch (IOException e) {
            area.append("Connection error: " + e.getMessage() + System.lineSeparator());
        }
    }

    public void sendMessage(String text) {
        if(socket == null)
            return;
        try {
            BufferedOutputStream bOut = new BufferedOutputStream(socket.getOutputStream());
            PrintWriter out = new PrintWriter(bOut, true);
            out.println(text);
        } catch (IOException e) {
            area.append("Connection error: " + e.getMessage() + System.lineSeparator());
        }
    }

    @Override
    public void run() {
        if(socket == null)
            return;
        try {
            BufferedReader in = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            while(!Thread.currentThread().isInterrupted()) {
                if(in.ready()) {
                    area.append("Server wrote: " + in.readLine() + System.lineSeparator());
                }
            }
        } catch (IOException e) {
            area.append("Connection error: " + e.getMessage() + System.lineSeparator());
        }
    }
}