The document describes a program for a multi-client chat client-server application using Java graphical programming. It includes the code for the ChatServer class that handles connections from multiple clients and broadcasts messages. It also includes the code for the ChatClient class that allows a client to connect to the server, send and receive messages, and view an online users list. The program allows for real-time text communication between multiple clients connected to a central server.

1. TUGAS
Membuat Program MultiClient Chatting Client-Server
Menggunakan Bahasa Pemrograman Java Berbasis Grafis
Oleh :
M. Ichsan Barokah
061130701305
6CD
JURUSAN TEKNIK KOMPUTER
POLITEKNIK NEGERI SRIWIJAYA
PALEMBANG

2. Chatting memungkinkan kita untuk selalu bisa berkomunikasi
walaupun kita tidak berada bersamanya di suatu tempat. Aplikasi chatting
merupakan suatu aplikasi yang memungkinkan pengguna (client)
berkomunikasi teks secara langsung (Real Time) dengan pengguna lain dengan
menggunakan media yang ada.
Hal yang harus dilakukan kita terlebih dahulu untuk menjalankan program
chatting ialah melakukan setting alamat IP pada masing-masing client.
Setelah melakukan konfigurasi IP pada masing-masingikomputer
kemudian kita juga harus memastikan bahwa firewall pada masing-masing
komputer harus diaktifkan karena pada beberapa kasus program ini tidak dapat saling
terkoneksi akibat firewall yang aktif pada sistem operasinya.
Berikut adalah listing program MultiClient Chatting Client-Server berbasis
grafis
 ChatServer.java
import java.io.*;
import java.net.*;
import java.util.*;
public class ChatServer {
private static int uniqueId;
private ArrayList<ChatServer.ClientThread> clients;
private int port;
private boolean keepGoing;
public ChatServer() {
this.port = 9999;
clients = new ArrayList();
}

3. public void start() {
keepGoing = true;
try {
ServerSocket serverSocket = new ServerSocket(port);
while (keepGoing) {
System.out.println("ChatServer waiting for Clients
on port " + port + ".");
Socket socket = serverSocket.accept();
if (!keepGoing) {
break;
}
ChatServer.ClientThread t = new
ChatServer.ClientThread(socket);
clients.add(t);
t.start();
send("login~" + t.username + "~" + t.username + "
sedang login...~Server~n");
}
try {
serverSocket.close();
for (int i = 0; i < clients.size(); ++i) {
ChatServer.ClientThread tc = clients.get(i);
try {
tc.sInput.close();
tc.sOutput.close();
tc.socket.close();
} catch (IOException ioE) {
}
}

4. } catch (Exception e) {
System.out.println("Exception closing the server
and clients: " + e);
}
} catch (IOException e) {
String msg = "Exception on new ServerSocket: " + e +
"n";
System.out.println(msg);
}
}
private synchronized void send(String message) {
for (int i = clients.size(); --i >= 0;) {
ChatServer.ClientThread ct = clients.get(i);
if (!ct.writeMsg(message)) {
clients.remove(i);
System.out.println("Disconnected Client " +
ct.username + " removed from list.");
}
}
}
private String getClients() {
String s = "";
for (ClientThread clientThread : clients) {
s += clientThread.username + ":";
}
s += "---";
System.out.println(s);

5. return s;
}
private synchronized void remove(int id) {
for (int i = 0; i < clients.size(); ++i) {
ChatServer.ClientThread ct = clients.get(i);
if (ct.id == id) {
clients.remove(i);
return;
}
}
}
public static void main(String[] args) {
ChatServer server = new ChatServer();
server.start();
}
private class ClientThread extends Thread {
private Socket socket;
private ObjectInputStream sInput;
private ObjectOutputStream sOutput;
private int id;
private String username;
public ClientThread(Socket socket) {
id = ++uniqueId;

6. this.socket = socket;
System.out.println("Menciptakan Object Input/Output
Streams");
try {
sOutput = new
ObjectOutputStream(socket.getOutputStream());
sInput = new
ObjectInputStream(socket.getInputStream());
String message = (String) sInput.readObject();
username = message.split("~")[1];
System.out.println(username + " masuk.");
} catch (IOException e) {
System.out.println("Exception creating new
Input/output Streams: " + e);
} catch (ClassNotFoundException e) {
}
}
@Override
public void run() {
boolean keepGoing = true;
while (keepGoing) {
String message;
try {
message = sInput.readObject().toString();
} catch (IOException e) {
System.out.println(username + " Exception
reading Streams: " + e);
break;

7. } catch (ClassNotFoundException e2) {
break;
}
String type = message.split("~")[0];
String pengirim = message.split("~")[1];
String text = message.split("~")[2];
String kepada = message.split("~")[3];
String response;
switch (type) {
case "postText":
response = "recieveText~" + pengirim + "~"
+ text + "~" + kepada + "~n";
send(response);
break;
case "postPrivateText":
response = "recievePrivateText~" +
pengirim + "~" + text + "~" + kepada + "~n";
send(response);
break;
case "login":
response = "login~" + pengirim + "~" +
text + "~" + kepada + "~n";
send(response);
break;
case "logout":
response = "logout~" + pengirim + "~" +
text + "~" + kepada + "~n";
send(response);

8. break;
case "list":
response = "list~server~" + getClients() +
"~ ~ ~ ~ ~n";
send(response);
break;
}
}
remove(id);
close();
}
private void close() {
try {
if (sOutput != null) {
sOutput.close();
}
} catch (Exception e) {
}
try {
if (sInput != null) {
sInput.close();
}
} catch (Exception e) {
}
try {
if (socket != null) {

9. socket.close();
}
} catch (Exception e) {
}
}
private boolean writeMsg(String msg) {
if (!socket.isConnected()) {
close();
return false;
}
try {
sOutput.writeObject(msg);
} catch (IOException e) {
System.out.println("Error sending message to " +
username);
System.out.println(e.toString());
}
return true;
}
}
}
ChatClient.java
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;

10. import java.util.ArrayList;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.table.DefaultTableModel;
public class ChatClient extends javax.swing.JFrame {
/**
* Creates new form ChatClient
*/
private ObjectInputStream input;
private ObjectOutputStream output;
private Socket socket;
private String server, username;
private int port;
private List<String> clients;
public ChatClient() {
clients = new ArrayList();
initComponents();
}
public boolean start() {
try {

11. socket = new Socket(server, port);
} catch (Exception ec) {
System.out.println("Error connectiong to server:" +
ec);
return false;
}
String msg = "Connection accepted " +
socket.getInetAddress() + ":" + socket.getPort();
System.out.println(msg);
try {
input = new
ObjectInputStream(socket.getInputStream());
output = new
ObjectOutputStream(socket.getOutputStream());
} catch (IOException eIO) {
System.out.println("Exception creating new
Input/output Streams: " + eIO);
return false;
}
new ChatClient.ListenFromServer().start();
try {
output.writeObject("login~" + username + "~" +
username + " sedang login...~server~n");
output.writeObject("list~" + username + "~" + username
+ " sedang login...~server~n");
} catch (IOException eIO) {

12. System.out.println("Exception doing login : " + eIO);
disconnect();
return false;
}
return true;
}
private void disconnect() {
try {
// TODO add your handling code here:
output.writeObject("logout~" + username + "~" +
username + " sudah logout...~Server~n");
} catch (IOException ex) {
//Logger.getLogger(ChatClient.class.getName()).log(Level.SEVERE,
null, ex);
}
try {
if (input != null) {
input.close();
}
} catch (Exception e) {
}
try {
if (output != null) {
output.close();
}

13. } catch (Exception e) {
}
try {
if (socket != null) {
socket.close();
}
} catch (Exception e) {
}
}
/**
* This method is called from within the constructor to
initialize the form.
* WARNING: Do NOT modify this code. The content of this
method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated
Code">
private void initComponents() {
jScrollPane1 = new javax.swing.JScrollPane();
viewTextArea = new javax.swing.JTextArea();
jScrollPane2 = new javax.swing.JScrollPane();
clientTable = new javax.swing.JTable();
postTextField = new javax.swing.JTextField();
kirimButton = new javax.swing.JButton();
lbljpg = new javax.swing.JLabel(new
ImageIcon("E:/rara.jpg"));

14. jLabel2 = new javax.swing.JLabel();
serverTextField = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
portTextField = new javax.swing.JTextField();
masukButton = new javax.swing.JButton();
jLabel4 = new javax.swing.JLabel();
usernameTextField = new javax.swing.JTextField();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE
);
viewTextArea.setEditable(false);
viewTextArea.setColumns(20);
viewTextArea.setLineWrap(true);
viewTextArea.setRows(5);
viewTextArea.setFocusable(false);
jScrollPane1.setViewportView(viewTextArea);
jScrollPane2.setViewportView(clientTable);
postTextField.addActionListener(new
java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent
evt) {
postTextFieldActionPerformed(evt);
}
});
kirimButton.setText("Kirim");

15. kirimButton.addActionListener(new
java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent
evt) {
kirimButtonActionPerformed(evt);
}
});
jLabel2.setText("Server");
serverTextField.setText("10.17.0.0");
jLabel3.setText("Port");
portTextField.setText("9999");
masukButton.setText("Masuk");
masukButton.addActionListener(new
java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent
evt) {
masukButtonActionPerformed(evt);
}
});
jLabel4.setText("Username");
usernameTextField.setText("Rara Ariesta");

16. javax.swing.GroupLayout layout = new
javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADI
NG)
.addGroup(layout.createSequentialGroup()
.addContainerGap()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Align
ment.LEADING)
.addGroup(layout.createSequentialGroup()
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Align
ment.LEADING)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING,
layout.createSequentialGroup()
.addComponent(postTextField)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addComponent(kirimButton))
.addComponent(jScrollPane1))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addComponent(jScrollPane2,
javax.swing.GroupLayout.PREFERRED_SIZE, 259,
javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(layout.createSequentialGroup()
.addComponent(lbljpg)
.addComponent(jLabel2)

17. .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addComponent(serverTextField,
javax.swing.GroupLayout.PREFERRED_SIZE, 167,
javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addComponent(portTextField,
javax.swing.GroupLayout.PREFERRED_SIZE, 46,
javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jLabel4)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addComponent(usernameTextField,
javax.swing.GroupLayout.DEFAULT_SIZE, 194, Short.MAX_VALUE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addComponent(masukButton)))
.addContainerGap())
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADI
NG)
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING,
layout.createSequentialGroup()
.addContainerGap()

18. .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Align
ment.BASELINE)
.addComponent(lbljpg)
.addComponent(jLabel2)
.addComponent(serverTextField,
javax.swing.GroupLayout.PREFERRED_SIZE,
javax.swing.GroupLayout.DEFAULT_SIZE,
javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(jLabel3)
.addComponent(portTextField,
javax.swing.GroupLayout.PREFERRED_SIZE,
javax.swing.GroupLayout.DEFAULT_SIZE,
javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(masukButton)
.addComponent(jLabel4)
.addComponent(usernameTextField,
javax.swing.GroupLayout.PREFERRED_SIZE,
javax.swing.GroupLayout.DEFAULT_SIZE,
javax.swing.GroupLayout.PREFERRED_SIZE))
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Align
ment.LEADING)
.addComponent(jScrollPane2,
javax.swing.GroupLayout.Alignment.TRAILING,
javax.swing.GroupLayout.DEFAULT_SIZE, 427, Short.MAX_VALUE)
.addGroup(layout.createSequentialGroup()
.addComponent(jScrollPane1)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATE
D)
.addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Align
ment.BASELINE)

19. .addComponent(postTextField,
javax.swing.GroupLayout.PREFERRED_SIZE,
javax.swing.GroupLayout.DEFAULT_SIZE,
javax.swing.GroupLayout.PREFERRED_SIZE)
.addComponent(kirimButton))))
.addContainerGap())
);
pack();
}// </editor-fold>
private void
masukButtonActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
this.server = serverTextField.getText();
this.port = new Integer(portTextField.getText());
this.username = usernameTextField.getText();
start();
}
private void
kirimButtonActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
try {
String message = "postText~" + username + "~" +
postTextField.getText() + "~all~n";
output.writeObject(message);
postTextField.setText("");
} catch (IOException ex) {

20. Logger.getLogger(ChatClient.class.getName()).log(Level.SEVERE,
null, ex);
}
}
private void
postTextFieldActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
kirimButtonActionPerformed(evt);
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and
feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available,
stay with the default look and feel.
* For details see
http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/pla
f.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info :
javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;

21. }
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(ChatClient.class.getName()).log
(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ChatClient.class.getName()).log
(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ChatClient.class.getName()).log
(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ChatClient.class.getName()).log
(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new ChatClient().setVisible(true);
}
});
}
// Variables declaration - do not modify

22. private javax.swing.JTable clientTable;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JButton kirimButton;
private javax.swing.JButton masukButton;
private javax.swing.JTextField portTextField;
private javax.swing.JTextField postTextField;
private javax.swing.JTextField serverTextField;
private javax.swing.JTextField usernameTextField;
private javax.swing.JTextArea viewTextArea;
private JLabel lbljpg ;
// End of variables declaration
class ListenFromServer extends Thread {
@Override
public void run() {
while (true) {
try {
String msg = (String) input.readObject();
String res;
String type = msg.split("~")[0];
String pengirim = msg.split("~")[1];
String text = msg.split("~")[2];
String kepada = msg.split("~")[3];

23. switch (type) {
case "recieveText":
res = pengirim + ": " + text;
viewTextArea.setText(viewTextArea.getText() + res + "n");
break;
case "recievePrivateText":
res = pengirim + ": " + text;
if (kepada.equals(username)) {
viewTextArea.setText(viewTextArea.getText() + res + "n");
}
break;
case "login":
viewTextArea.setText(viewTextArea.getText() + pengirim + " sudah
login..." + "n");
clients.add(pengirim);
break;
case "logout":
viewTextArea.setText(viewTextArea.getText() + pengirim + " telah
logout..." + "n");
clients.remove(pengirim);
break;
case "list":
setTable(text);
break;
}
} catch (IOException e) {

24. System.out.println("Server has close the
connection: " + e);
break;
} catch (ClassNotFoundException e2) {
}
}
}
private void setTable(String text) {
int rows = text.split(":").length - 1;
Object[][] data = new Object[rows][1];
for (int i = 0; i < rows; i++) {
String t = text.split(":")[i];
data[i][0] = t;
}
String[] header = {"Clients"};
clientTable.setModel(new DefaultTableModel(data,
header));
}
}
}
Jika dijalankan maka tampilan akan seperti berikut: