ServerGUI.java

import javax.swing.JFrame;

import java.io.*;
import java.net.*;

import javax.swing.JPanel;

import java.awt.SystemColor;

import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.JRadioButton;
import javax.swing.JButton;
import javax.swing.SwingUtilities;

import java.awt.Toolkit;

import javax.swing.ButtonGroup;

import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;

import org.eclipse.wb.swing.FocusTraversalOnArray;

import java.awt.Component;

public class ServerGUI extends JFrame implements ActionListener {

    private static final long serialVersionUID = 1L;
    private JFrame frame;
    public JTextField enterField;
    public JTextField txtServerIP;
    public JTextField txtPort;
    public JTextArea displayArea;
    private final ButtonGroup buttonGroup = new ButtonGroup();
    private ObjectOutputStream output;
    private ObjectInputStream input;
    private ServerSocket server;
    private Socket connection;
    private int counter = 1;

    // private InetAddress ip;

    public static void main(String[] args) {
        // EventQueue.invokeLater(new Runnable() {
        // public void run() {
        // try {
        ServerGUI window = new ServerGUI();
        window.frame.setVisible(true);

        window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // } catch (Exception e) {
        // e.printStackTrace();
        // }
        // }
        // });
    }

    public ServerGUI() {
        super("Sunucu Arayüzü");

        initialize();

    }

    private void initialize() {
        frame = new JFrame();
        frame.setIconImage(Toolkit
                .getDefaultToolkit()
                .getImage(
                        ServerGUI.class
                                .getResource("/javax/swing/plaf/metal/icons/ocean/computer.gif")));
        frame.setBounds(100, 100, 640, 480);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(null);

        JPanel panel1 = new JPanel();
        panel1.setBackground(SystemColor.inactiveCaptionBorder);
        panel1.setBounds(10, 11, 604, 100);
        frame.getContentPane().add(panel1);
        panel1.setLayout(null);

        JLabel lblIp = new JLabel("Your IP Address");
        lblIp.setBounds(10, 71, 89, 14);
        panel1.add(lblIp);

        JLabel lblPortNum = new JLabel("Port Number");
        lblPortNum.setBounds(10, 38, 89, 14);
        panel1.add(lblPortNum);

        txtServerIP = new JTextField();
        txtServerIP.setEnabled(false);
        txtServerIP.setEditable(false);
        txtServerIP.setBounds(111, 68, 200, 20);
        panel1.add(txtServerIP);
        txtServerIP.setColumns(10);

        txtPort = new JTextField();
        txtPort.setText("14789");
        txtPort.setToolTipText("14789 is default port");
        txtPort.setBounds(111, 35, 200, 20);
        panel1.add(txtPort);
        txtPort.setColumns(10);

        JLabel lblProtocolSelection = new JLabel("Select Protocol");
        lblProtocolSelection.setBounds(356, 11, 90, 14);
        panel1.add(lblProtocolSelection);

        JRadioButton rdbtnTcp = new JRadioButton("TCP");
        rdbtnTcp.setBackground(SystemColor.inactiveCaptionBorder);
        buttonGroup.add(rdbtnTcp);
        rdbtnTcp.setSelected(true);
        rdbtnTcp.setBounds(352, 30, 76, 23);
        panel1.add(rdbtnTcp);

        JRadioButton rdbtnUdp = new JRadioButton("UDP");
        rdbtnUdp.setBackground(SystemColor.inactiveCaptionBorder);
        buttonGroup.add(rdbtnUdp);
        rdbtnUdp.setBounds(352, 55, 76, 23);
        panel1.add(rdbtnUdp);

        JButton btnStartConnection = new JButton("Start Connection");
        btnStartConnection.addActionListener(this);

        btnStartConnection.setBounds(458, 10, 136, 78);
        panel1.add(btnStartConnection);
        panel1.setFocusTraversalPolicy(new FocusTraversalOnArray(
                new Component[] { lblProtocolSelection, txtPort,
                        txtServerIP, rdbtnTcp, rdbtnUdp, btnStartConnection,
                        lblIp, lblPortNum }));

        JPanel panel2 = new JPanel();
        panel2.setBounds(10, 122, 604, 309);
        frame.getContentPane().add(panel2);
        panel2.setLayout(null);

        displayArea = new JTextArea();
        displayArea.setEditable(false);
        displayArea.setBounds(10, 11, 584, 247);
        panel2.add(displayArea);

        enterField = new JTextField();
        enterField.addActionListener(new ActionListener() {
            public void actionPerformed(ActionEvent e) {
                sendData(e.getActionCommand());
                enterField.setText("");
            }
        });
        enterField.setBounds(10, 269, 584, 29);
        panel2.add(enterField);
        enterField.setColumns(10);
    }

    public void actionPerformed(ActionEvent a) {
        try {
            txtServerIP.setText(getIPAddress());
        } catch (IOException e1) {

            e1.printStackTrace();
        }

        try {
            runServer();
        } catch (IOException e2) {

            e2.printStackTrace();
        }
    }

    private void sendData(String message) {
        // send object to client
        try {
            output.writeObject("SERVER > " + message);
            output.flush();
            displayMessage("SERVER > " + message);
        }

        // process problems sending object
        catch (IOException ioException) {
            displayArea.append("Error writing object.");
        }
    }

    private void displayMessage(final String messageToDisplay) {
        // display message from event-dispatch thread of execution
        SwingUtilities.invokeLater(new Runnable() { // inner class to ensure GUI
                                                    // updates properly

                    public void run() // updates displayArea
                    {
                        displayArea.append("\n" + messageToDisplay);
                        displayArea.setCaretPosition(displayArea.getText()
                                .length());
                    }

                } // end inner class
                ); // end call to SwingUtilities.invokeLater
    }

    public void runServer() throws IOException {
        // set up server to receive connections; process connections
        try {

            // Step 1: Create a ServerSocket.
            int portNum = Integer.parseInt(txtPort.getText());
            server = new ServerSocket(portNum, 100);

            while (true) {

                try {
                    waitForConnection(); // Step 2: Wait for a connection.
                    getStreams(); // Step 3: Get input & output streams.
                    processConnection(); // Step 4: Process connection.
                }

                // process EOFException when client closes connection
                catch (EOFException eofException) {
                    System.err.println("Client terminated the connection.");
                }

                finally {
                    closeConnection(); // Step 5: Close connection.
                    ++counter;
                }

            } // end while

        } // end try

        // process problems with I/O
        catch (IOException ioException) {
            ioException.printStackTrace();
        }

    } // end method runServer

    private void waitForConnection() throws IOException {
        displayMessage("Waiting for client to connect...");
        connection = server.accept(); // allow server to accept connection
        displayMessage("Connection " + counter + " from "
                + connection.getInetAddress().getHostName() + " ("
                + connection.getInetAddress().getHostAddress()
                + ") established.");
    }

    // get streams to send and receive data
    private void getStreams() throws IOException {
        // set up output stream for objects
        output = new ObjectOutputStream(connection.getOutputStream());
        output.flush(); // flush output buffer to send header information

        // set up input stream for objects
        input = new ObjectInputStream(connection.getInputStream());

        displayMessage("I/O stream receieved.");
    }

    // process connection with client
    private void processConnection() throws IOException {
        // send connection successful message to client
        String message = "Connected.";
        sendData(message);

        // enable enterField so server user can send messages
        setTextFieldEditable(true);

        do { // process messages sent from client

            // read message and display it
            try {
                message = (String) input.readObject();
                displayMessage(message);
            }

            // catch problems reading from client
            catch (ClassNotFoundException classNotFoundException) {
                displayMessage("Unknown object type receieved.");
            }

        } while (!message.equals("TEMINATE"));

    } // end method processConnection

    // close streams and socket
    private void closeConnection() {
        displayMessage("Closing connection...");
        setTextFieldEditable(false); // disable enterField

        try {
            output.close();
            input.close();
            connection.close();
            displayMessage("Connection closed.");
        } catch (IOException ioException) {
            ioException.printStackTrace();
        }
    }

    private void setTextFieldEditable(final boolean editable) {
        // display message from event-dispatch thread of execution
        SwingUtilities.invokeLater(new Runnable() { // inner class to ensure GUI
                                                    // updates properly

                    public void run() // sets enterField's editability
                    {
                        enterField.setEditable(editable);
                    }

                } // end inner class

                ); // end call to SwingUtilities.invokeLater
    }

    public String getIPAddress() throws IOException {

        return InetAddress.getLocalHost().getHostAddress();
    }

}