Dodit Suprianto

/*
---------------------------------------------------------
 Dodit Suprianto dodit.suprianto@polinema.ac.id
 Mata Kuliah Pemrograman Jaringan
 September 2020, Implementasi Socket TCP pada Java Swing
 http://doditsuprianto.blogspot.com
---------------------------------------------------------
 Thanks and Credit to Steven Ou (ochinchina)
 https://gist.github.com/ochinchina/72cc23220dc8a933fc46
---------------------------------------------------------
 */

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.net.UnknownHostException;
import java.nio.ByteBuffer;
import java.nio.channels.AsynchronousSocketChannel;
import java.nio.channels.CompletionHandler;
import java.util.concurrent.atomic.AtomicInteger;

import java.nio.channels.AsynchronousServerSocketChannel;

public class frmDemoSocketJava {
    private JTabbedPane tabbedPane1;
    private JPanel panel1;
    private JTextField txtPortServer;
    private JTextField txtIPServer;
    private JButton btnListen;
    private JTextField txtPesanDiterimaServer;
    private JTextField txtPortClient;
    private JTextField txtAlamatIPTujuan;
    private JTextField txtPesanDikirimKeServer;
    private JButton btnKirim;

    public frmDemoSocketJava() {
        btnListen.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                //JOptionPane.showMessageDialog(null, "Tombol LISTENER diklik");
                try {
                    new Thread(() -> {
                        try {
                            EchoServer(txtIPServer.getText(), Integer.parseInt(txtPortServer.getText()));
                        } catch (IOException ioException) {
                            ioException.printStackTrace();
                        }
                    }).start();
                } catch(Exception ex) {
                    JOptionPane.showMessageDialog(null, ex.getMessage());
                }
            }
        });

        btnKirim.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                //JOptionPane.showMessageDialog(null, "Tombol KIRIM diklik");
                try {
                    AtomicInteger messageWritten = new AtomicInteger(0);
                    AtomicInteger messageRead = new AtomicInteger(0);

                    EchoClient(txtAlamatIPTujuan.getText(), Integer.parseInt(txtPortClient.getText()), txtPesanDikirimKeServer.getText(), messageWritten, messageRead);
                } catch (Exception ex) {
                    JOptionPane.showMessageDialog(null, ex.getMessage());
                }
            }
        });
    }

    public static void main(String[] args){
        JFrame gui = new JFrame("Socket Java");
        gui.setContentPane(new frmDemoSocketJava().panel1);
        gui.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        gui.pack();
        gui.setVisible(true);
    }

    //////////////////////////
    // Socket Client Helper //
    //////////////////////////
    public void EchoClient( String host, int port, final String message, final AtomicInteger messageWritten, final AtomicInteger messageRead ) throws IOException {
        //create a socket channel
        AsynchronousSocketChannel sockChannel = AsynchronousSocketChannel.open();

        //try to connect to the server side
        sockChannel.connect( new InetSocketAddress(host, port), sockChannel, new CompletionHandler<Void, AsynchronousSocketChannel >() {
            @Override
            public void completed(Void result, AsynchronousSocketChannel channel ) {
                //start to read message
                startRead( channel,messageRead );

                //write an message to server side
                startWrite( channel, message, messageWritten );
            }

            @Override
            public void failed(Throwable exc, AsynchronousSocketChannel channel) {
                System.out.println( "fail to connect to server");
            }

        });
    }

    private void startRead( final AsynchronousSocketChannel sockChannel, final AtomicInteger messageRead ) {
        final ByteBuffer buf = ByteBuffer.allocate(2048);

        sockChannel.read( buf, sockChannel, new CompletionHandler<Integer, AsynchronousSocketChannel>(){

            @Override
            public void completed(Integer result, AsynchronousSocketChannel channel) {
                //message is read from server
                messageRead.getAndIncrement();

                //print the message
                System.out.println( "Read message:" + new String( buf.array()) );
            }

            @Override
            public void failed(Throwable exc, AsynchronousSocketChannel channel) {
                System.out.println( "fail to read message from server");
            }
        });
    }

    private void startWrite( final AsynchronousSocketChannel sockChannel, final String message, final AtomicInteger messageWritten ) {
        ByteBuffer buf = ByteBuffer.allocate(2048);
        buf.put(message.getBytes());
        buf.flip();
        messageWritten.getAndIncrement();
        sockChannel.write(buf, sockChannel, new CompletionHandler<Integer, AsynchronousSocketChannel >() {
            @Override
            public void completed(Integer result, AsynchronousSocketChannel channel ) {
                //after message written
                //NOTHING TO DO
            }

            @Override
            public void failed(Throwable exc, AsynchronousSocketChannel channel) {
                System.out.println( "Fail to write the message to server");
            }
        });
    }

    ///////////////////
    // Socket Server //
    //////////////////
    public void EchoServer( String bindAddr, int bindPort ) throws IOException {
        InetSocketAddress sockAddr = new InetSocketAddress(bindAddr, bindPort);

        //create a socket channel and bind to local bind address
        AsynchronousServerSocketChannel serverSock =  AsynchronousServerSocketChannel.open().bind(sockAddr);

        //start to accept the connection from client
        serverSock.accept(serverSock, new CompletionHandler<AsynchronousSocketChannel,AsynchronousServerSocketChannel >() {

            @Override
            public void completed(AsynchronousSocketChannel sockChannel, AsynchronousServerSocketChannel serverSock ) {
                //a connection is accepted, start to accept next connection
                serverSock.accept( serverSock, this );
                //start to read message from the client
                startRead( sockChannel );

            }

            @Override
            public void failed(Throwable exc, AsynchronousServerSocketChannel serverSock) {
                System.out.println( "fail to accept a connection");
            }

        });
    }

    private void startRead( AsynchronousSocketChannel sockChannel ) {
        final ByteBuffer buf = ByteBuffer.allocate(2048);

        //read message from client
        sockChannel.read( buf, sockChannel, new CompletionHandler<Integer, AsynchronousSocketChannel >() {

            /**
             * some message is read from client, this callback will be called
             */
            @Override
            public void completed(Integer result, AsynchronousSocketChannel channel  ) {
                buf.flip();

                // echo the message
                startWrite( channel, buf );

                //start to read next message again
                startRead( channel );

                // menampilkan string pesan ke textfield txtPesanDiterimaServer
                txtPesanDiterimaServer.setText(new String( buf.array()));
            }

            @Override
            public void failed(Throwable exc, AsynchronousSocketChannel channel ) {
                System.out.println( "fail to read message from client");
            }
        });
    }

    private void startWrite( AsynchronousSocketChannel sockChannel, final ByteBuffer buf) {
        sockChannel.write(buf, sockChannel, new CompletionHandler<Integer, AsynchronousSocketChannel >() {

            @Override
            public void completed(Integer result, AsynchronousSocketChannel channel) {
                //finish to write message to client, nothing to do
            }

            @Override
            public void failed(Throwable exc, AsynchronousSocketChannel channel) {
                //fail to write message to client
                System.out.println( "Fail to write message to client");
            }

        });
    }
}