I am reading the book Head First Java.
Reading the chapter 'networking and threads' I tried to run a project in my Eclipse IDE that consists of a chat server and chat clients.
The problem is that I am getting no feedback in the clients text area and debugging seems to have problem inside a running thread.
Here is the code:
VerySimpleChatServer.java :
package mypackage;
import java.io.*;
import java.net.*;
import java.util.*;
public class VerySimpleChatServer {
ArrayList clientOutputStreams;
//Inner class ClientHandler
public class ClientHandler implements Runnable
{
BufferedReader reader;
Socket sock;
public ClientHandler(Socket clientSocket)
{
try
{
sock = clientSocket;
InputStreamReader isReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(isReader);
}
catch(Exception ex)
{
ex.printStackTrace();
}
}//close constructor
public void run()
{
String message;
try
{
while((message = reader.readLine()) != null)
{
System.out.println("read " + message);
tellEveryone(message);
}//close while
}
catch(Exception ex)
{
ex.printStackTrace();
}
}//close run
}//close inner class
public static void main(String[] args) {
// TODO Auto-generated method stub
new VerySimpleChatServer().go();
}
public void go()
{
clientOutputStreams = new ArrayList();
try
{
ServerSocket serverSock = new ServerSocket(5000);
while(true)
{
Socket clientSocket = serverSock.accept();
PrintWriter writer = new PrintWriter(clientSocket.getOutputStream());
clientOutputStreams.add(writer);
Thread t = new Thread(new ClientHandler(clientSocket));
t.start();
System.out.println("got a connection");
}
}
catch(Exception ex)
{
ex.printStackTrace();
}
}//close go
public void tellEveryone(String message)
{
Iterator it = clientOutputStreams.iterator();
while(it.hasNext())
{
try
{
PrintWriter writer = (PrintWriter)it.next();
writer.println(message);
writer.flush();
}
catch(Exception ex)
{
ex.printStackTrace();
}
}//end while
}//close tellEveryone
}//close class
SimpleChatClient.java :
package mypackage;
import java.io.*;
import java.net.*;
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SimpleChatClient {
JTextArea incoming;
JTextField outgoing;
BufferedReader reader;
PrintWriter writer;
Socket sock;
public static void main(String[] args) {
// TODO Auto-generated method stub
SimpleChatClient client = new SimpleChatClient();
client.go();
}
public void go()
{
JFrame frame = new JFrame("Ludicrously Simple Chat Client");
JPanel mainPanel = new JPanel();
incoming = new JTextArea(15, 50);
incoming.setLineWrap(true);
incoming.setWrapStyleWord(true);
incoming.setEditable(false);
JScrollPane qScroller = new JScrollPane(incoming);
qScroller.setVerticalScrollBarPolicy(ScrollPaneConstants.VERTICAL_SCROLLBAR_ALWAYS);
qScroller.setHorizontalScrollBarPolicy(ScrollPaneConstants.HORIZONTAL_SCROLLBAR_NEVER);
outgoing = new JTextField(20);
JButton sendButton = new JButton("Send");
sendButton.addActionListener(new SendButtonListener());
mainPanel.add(qScroller);
mainPanel.add(outgoing);
mainPanel.add(sendButton);
setUpNetworking();
Thread readerThread = new Thread(new IncomingReader());
readerThread.start();
frame.add(mainPanel, BorderLayout.CENTER);
frame.setSize(400, 500);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}//close go
private void setUpNetworking()
{
try
{
sock = new Socket("127.0.0.1", 5000);
InputStreamReader streamReader = new InputStreamReader(sock.getInputStream());
reader = new BufferedReader(streamReader);
writer = new PrintWriter(sock.getOutputStream());
System.out.println("networking established");
}
catch(IOException ex)
{
ex.printStackTrace();
}
}//close setUpNetworking
//inner class
public class SendButtonListener implements ActionListener
{
public void actionPerformed(ActionEvent ev)
{
try
{
writer.println(outgoing.getText());
writer.flush();
}
catch(Exception ex)
{
ex.printStackTrace();
}
outgoing.setText("");
outgoing.requestFocus();
}
}//close inner class
//inner class
public class IncomingReader implements Runnable
{
public void run()
{
String message;
try
{
while ( (message = reader.readLine()) != null)
{
System.out.println("read " + message);
incoming.append(message + "\n");
}//close while
}
catch(Exception ex)
{
ex.printStackTrace();
}
}//close run
}//close inner class
}
Any ideas?
Thank you very much.