ChatClient.java

package chat;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.List;
import javax.swing.DefaultListModel;
import javax.swing.JCheckBox;

import javax.swing.JFrame;
import javax.swing.JList;
import javax.swing.JOptionPane;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;

/**
 * A simple Swing-based client for the chat server.  Graphically
 * it is a frame with a text field for entering messages and a
 * textarea to see the whole dialog.
 *
 * The client follows the Chat Protocol which is as follows.
 * When the server sends "SUBMITNAME" the client replies with the
 * desired screen name.  The server will keep sending "SUBMITNAME"
 * requests as long as the client submits screen names that are
 * already in use.  When the server sends a line beginning
 * with "NAMEACCEPTED" the client is now allowed to start
 * sending the server arbitrary strings to be broadcast to all
 * chatters connected to the server.  When the server sends a
 * line beginning with "MESSAGE " then all characters following
 * this string should be displayed in its message area.
 */
public class ChatClient {

    BufferedReader in;
    PrintWriter out;
    JFrame frame = new JFrame("Chatter");
    JTextField textField = new JTextField(40);
    JTextArea messageArea = new JTextArea(8, 40);
    
    JCheckBox broCast = new JCheckBox();
    JList<String> nameList = new JList<>();
    String clientName;

    /**
     * Constructs the client by laying out the GUI and registering a
     * listener with the textfield so that pressing Return in the
     * listener sends the textfield contents to the server.  Note
     * however that the textfield is initially NOT editable, and
     * only becomes editable AFTER the client receives the NAMEACCEPTED
     * message from the server.
     */
    public ChatClient() {

        // Layout GUI
        textField.setEditable(false);
        messageArea.setEditable(false);
        frame.getContentPane().add(textField, "North");
        frame.getContentPane().add(new JScrollPane(messageArea), "Center");
        frame.getContentPane().add(broCast, "South");
        frame.getContentPane().add(new JScrollPane(nameList), "West");
        frame.pack();
        
        // Add Listeners
        textField.addActionListener(new ActionListener() {
            /**
             * Responds to pressing the enter key in the textfield by sending
             * the contents of the text field to the server.    Then clear
             * the text area in preparation for the next message.
             */
            public void actionPerformed(ActionEvent e) {
                
                List<String> userSelect = nameList.getSelectedValuesList();
                
                /*
                 * selecting the message type
                 */
                
                if(broCast.isSelected()){
                    out.println("BROADCAST"+textField.getText());
                }
                else if(userSelect.size() == 0){
                    out.println(textField.getText());
                }
                else{
//                    for(String name : userSelect){
//                        out.println("MULTICAST"+ name + textField.getText());
//                    }
                    
                	/*
                	 * sending the receiver list to server 
                	 * 
                	 */
                	
                    String sendlist="";
                    
                    for(int i=0; i < userSelect.size(); i++){
                        sendlist += userSelect.get(i) + "$";
                    }
                    
                    System.out.println(userSelect);
                    System.out.println(sendlist);
                    
                    out.println("MULTICAST"+ sendlist + "%" + textField.getText()); 
                }
                textField.setText("");
            }
        });
        
    }

    /**
     * Prompt for and return the address of the server.
     */
    private String getServerAddress() {
        return JOptionPane.showInputDialog(
            frame,
            "Enter IP Address of the Server:",
            "Welcome to the Chatter",
            JOptionPane.QUESTION_MESSAGE);
    }

    /**
     * Prompt for and return the desired screen name.
     */
    private String getName() {
        return JOptionPane.showInputDialog(
            frame,
            "Choose a screen name:",
            "Screen name selection",
            JOptionPane.PLAIN_MESSAGE);
    }

    /**
     * Connects to the server then enters the processing loop.
     */
    private void run() throws IOException {

        // Make connection and initialize streams
        String serverAddress = getServerAddress();
        Socket socket = new Socket(serverAddress, 9001);
        in = new BufferedReader(new InputStreamReader(
            socket.getInputStream()));
        out = new PrintWriter(socket.getOutputStream(), true);

        // Process all messages from server, according to the protocol.
        while (true) {
            String line = in.readLine();

            if (line.startsWith("SUBMITNAME")) {
                out.println(clientName=getName());
            } else if (line.startsWith("NAMEACCEPTED")) {
                textField.setEditable(true);
                frame.setTitle("Username :" + clientName + "  ** Chat Room **");
            } else if (line.startsWith("MESSAGE")) {
                messageArea.append(line.substring(8) + "\n");
            }
            else if(line.startsWith("NAMELIST"))
            {
            	/*
            	 * Adding available client names to list
            	 */
            	
                line = line.substring(8);
                String activeNames[] = line.split(":");
                DefaultListModel<String> dlm = new DefaultListModel<String>();
                for(String aN:activeNames)
                {
                    dlm.addElement(aN);
                }
                nameList.setModel(dlm);

            }
        }
    }

    /**
     * Runs the client as an application with a closeable frame.
     */
    public static void main(String[] args) throws Exception {
        ChatClient client = new ChatClient();
        client.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        client.frame.setVisible(true);
        client.run();
    }
}