Client.java

import java.io.*;
import java.net.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Client extends JFrame{
   
   private JTextField userText;
   private JTextArea chatWindow;
   private ObjectOutputStream output;
   private ObjectInputStream input;
   private String message = "";
   private String serverIP;
   private Socket connection;
   
   //constructor
   public Client(String host){
      super("Client !");
      serverIP = host;
      userText = new JTextField();
      userText.setEditable(false);
      userText.addActionListener(
         new ActionListener(){
            public void actionPerformed(ActionEvent event){
               sendMessage(event.getActionCommand());
               userText.setText("");
            }
         }
      );
      add(userText, BorderLayout.NORTH);
      chatWindow = new JTextArea();
      add(new JScrollPane(chatWindow), BorderLayout.CENTER);
      setSize(300,150);
      setVisible(true);
   }
   
   //connect to server
   public void startRunning(){
      try{
         connectToServer();
         setupStreams();
         whileChatting();
      }catch(EOFException eofException){
         showMessage("\n Client terminated connection");
      }catch(IOException ioException){
         ioException.printStackTrace();
      }finally{
         closeCrap();
      }
   }
   
   //connect to server
   private void connectToServer() throws IOException{
      showMessage("Attempting connection... \n");
      connection = new Socket(InetAddress.getByName(serverIP), 6789);
      showMessage("Connected to: " + connection.getInetAddress().getHostName() );
   }
   
   //set up streams to send and receive messages
   private void setupStreams() throws IOException{
      output = new ObjectOutputStream(connection.getOutputStream());
      output.flush();
      input = new ObjectInputStream(connection.getInputStream());
      showMessage("\n Friends your streams are now good to go! \n");
   }
   
   //while chatting with server
   private void whileChatting() throws IOException{
      ableToType(true);
      do{
         try{
            message = (String) input.readObject();
            showMessage("\n" + message);
         }catch(ClassNotFoundException classNotfoundException){
            showMessage("\n I dont know that object type");
         }
      }while(!message.equals("SERVER - END"));
   }
   
   //close the streams and sockets
   private void closeCrap(){
      showMessage("\n SHUT DOWN CLIENT NOW...");
      ableToType(false);
      try{
         output.close();
         input.close();
         connection.close();
      }catch(IOException ioException){
         ioException.printStackTrace();
      }
   }
   
   //send messages to server
   private void sendMessage(String message){
      try{
         output.writeObject("CLIENT - " + message);
         output.flush();
         showMessage("\nCLIENT - " + message);
      }catch(IOException ioException){
         chatWindow.append("\n something messed up sending message !");
      }
   }
   
   //change/update chatWindow
   private void showMessage(final String m){
      SwingUtilities.invokeLater(
         new Runnable(){
            public void run(){
               chatWindow.append(m);
            }
         }
      );
   }
   
   //gives user permission to type crap into the text box
   private void ableToType(final boolean tof){
      SwingUtilities.invokeLater(
         new Runnable(){
            public void run(){
               userText.setEditable(tof);
            }
         }
      );      
   }
}