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Java SocketChannel not receiving incoming data properly

I'm writing a chat room server which takes message from a chat client and broadcasts out the message to all users. This is an exercise from a book called An Introduction to Network Programming with Java: Java 7 Compatible with which I'm self-teaching Java networking basics. I wrote a GUI frontend for the chat room and implemented the server backend, following examples from the code in the book. However, when I tested the code with chat clients, the server seemed unable to receive clients' data. I can't figure out why. The code for the chat room (here it was made in command line mode for test purpose) and the client is as followings. Thank you.
// code for the server backend, problem seems to be lie in here.
/**
* The multiecho server itself
*/
package channelEchoServer;
import java.net.*;
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import java.util.*;
public class MultiEchoServerNIO {
private static ServerSocketChannel serverSocketChannel;
private static final int PORT = 1234;
private static Selector selector;
private static Vector<SocketChannel> socketChannelVec;
private static Vector<ChatUser> allUsers;
public static final int CAPACITY = 20;
public static final int BUFFER_SIZE = 2048;
public static final String NEW_LINE = System.lineSeparator();
public static void main(String[] args) {
ServerSocket serverSocket = null;
try {
serverSocketChannel = ServerSocketChannel.open();
serverSocketChannel.configureBlocking(false);
serverSocket = serverSocketChannel.socket();
InetSocketAddress netAddress = new InetSocketAddress(PORT);
serverSocket.bind(netAddress);
selector = Selector.open();
serverSocketChannel.register(selector, SelectionKey.OP_ACCEPT);
}
catch (IOException ioEx) {
ioEx.printStackTrace();
System.exit(1);
}
socketChannelVec = new Vector<>(CAPACITY);
allUsers = new Vector<>(CAPACITY);
System.out.println("Server is opened ...");
processConnections();
}
private static void processConnections () {
do {
try {
int numKeys = selector.select();
System.out.println(numKeys + " keys selected.");
if (numKeys > 0) {
Set eventKeys = selector.selectedKeys();
Iterator keyCycler = eventKeys.iterator();
while (keyCycler.hasNext()) {
SelectionKey key = (SelectionKey)keyCycler.next();
int keyOps = key.readyOps();
if ((keyOps & SelectionKey.OP_ACCEPT) == SelectionKey.OP_ACCEPT) {
acceptConnection(key);
continue;
}
if ((keyOps & SelectionKey.OP_READ) == SelectionKey.OP_READ) {
acceptData(key);
}
}
}
}
catch (IOException ioEx) {
ioEx.printStackTrace();
System.exit(1);
}
} while (true);
}
private static void acceptConnection (SelectionKey key) throws IOException {
SocketChannel socketChannel;
Socket socket;
socketChannel = serverSocketChannel.accept();
socketChannel.configureBlocking(false);
socket = socketChannel.socket();
System.out.println("Connection on " + socket + ".");
socketChannel.register(selector, SelectionKey.OP_READ);
socketChannelVec.add(socketChannel);
selector.selectedKeys().remove(key);
}
private static void acceptData (SelectionKey key) throws IOException {
SocketChannel socketChannel;
Socket socket;
ByteBuffer buffer = ByteBuffer.allocate(BUFFER_SIZE);
socketChannel = (SocketChannel) key.channel();
buffer.clear();
int numBytes = socketChannel.read(buffer);
socket = socketChannel.socket();
if (numBytes == -1) {
key.cancel();
closeSocket(socket);
}
else {
String chatName = null;
byte[] byteArray = buffer.array();
if (byteArray[0] == '#')
announceNewUser(socketChannel, buffer);
else {
for (ChatUser chatUser : allUsers)
if (chatUser.getUserSocketChannel().equals(socketChannel))
chatName = chatUser.getChatName();
broadcastMessage(chatName, buffer);
}
}
}
private static void closeSocket (Socket socket) {
try {
if (socket != null)
socket.close();
}
catch (IOException ioEx) {
System.out.println("Unable to close socket!");
}
}
public static void announceNewUser (SocketChannel userSocketChannel, ByteBuffer buffer) {
ChatUser chatUser;
byte[] byteArray = buffer.array();
int messageSize = buffer.position();
String chatName = new String(byteArray, 1, messageSize);
if (chatName.indexOf("\n") >= 0)
chatName = chatName.substring(0, chatName.indexOf("\n"));
chatUser = new ChatUser(userSocketChannel, chatName);
allUsers.add(chatUser);
if (!socketChannelVec.remove(userSocketChannel)) {
System.out.println("Can't find user!");
return;
} // we should save userSocketChannel in a chatUser instance before deleting it.
chatName = chatUser.getChatName();
System.out.println(chatName + " entered the chat room at " + new Date() + "." + NEW_LINE);
String welcomeMessage = "Welcome " + chatName + "!" + NEW_LINE;
byte[] bytes = welcomeMessage.getBytes();
buffer.clear();
for (int i = 0; i < welcomeMessage.length(); i++)
buffer.put(bytes[i]);
buffer.flip();
try {
chatUser.getUserSocketChannel().write(buffer);
}
catch (IOException ioEx) {
ioEx.printStackTrace();
}
}
public static void announceExit (String name) {
System.out.println(name + " left chat room at " + new Date() + "." + NEW_LINE);
for (ChatUser chatUser : allUsers) {
if (chatUser.getChatName().equals(name))
allUsers.remove(chatUser);
}
}
public static void broadcastMessage (String chatName, ByteBuffer buffer) {
String messagePrefix = chatName + ": ";
byte[] messagePrefixBytes = messagePrefix.getBytes();
final byte[] CR = NEW_LINE.getBytes();
try {
int messageSize = buffer.position();
byte[] messageBytes = buffer.array();
byte[] messageBytesCopy = new byte[messageSize];
String userMessage = new String(messageBytes, 0, messageSize);
if (userMessage.equals("Bye"))
announceExit(chatName);
for (int i = 0; i < messageSize; i++)
messageBytesCopy[i] = messageBytes[i];
buffer.clear();
buffer.put(messagePrefixBytes);
for (int i = 0; i < messageSize; i++)
buffer.put(messageBytesCopy[i]);
buffer.put(CR);
SocketChannel chatSocketChannel;
for (ChatUser chatUser : allUsers) {
chatSocketChannel = chatUser.getUserSocketChannel();
buffer.flip();
chatSocketChannel.write(buffer);
}
}
catch (IOException ioEx) {
ioEx.printStackTrace();
}
}
}
class ChatUser {
private SocketChannel userSocketChannel;
private String chatName;
public ChatUser (SocketChannel userSocketChannel, String chatName) {
this.userSocketChannel = userSocketChannel;
this.chatName = chatName;
}
public SocketChannel getUserSocketChannel () {
return userSocketChannel;
}
public String getChatName () {
return chatName;
}
}
// Code for a chat client for testing purpose
package multithreadEchoChatroomClientGUI;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.net.*;
import java.util.*;
public class MultithreadEchoChatroomClient1 {
private static Socket socket;
private static InetAddress host;
private static String address;
public static final int PORT = 1234;
public static void main(String[] args) {
address = JOptionPane.showInputDialog("Enter the host name or IP address:");
try {
host = InetAddress.getByName(address);
}
catch (UnknownHostException uhEx) {
JOptionPane.showMessageDialog(null, "Unknown Host!", "Error", JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
try {
socket = new Socket(host, PORT);
}
catch (IOException ioEx) {
JOptionPane.showMessageDialog(null, ioEx.toString(), "Error", JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
SwingUtilities.invokeLater(new Runnable () {
public void run () {
ClientFrame client = new ClientFrame(host, socket, address);
client.setTitle("Chat");
client.setSize(400, 500);
client.setVisible(true);
new Thread(client).start();
}
});
}
}
class ClientFrame extends JFrame implements Runnable {
private InetAddress host;
private String address;
private Socket socket;
private Scanner input;
private PrintWriter output;
private JMenuItem connect;
private JTextArea serverResponseArea;
private JTextArea messageArea;
private JTextField messageFiled;
private JButton sendButton;
private String serverResponse;
private String clientName;
public ClientFrame (InetAddress host, Socket socket, String address) {
this.host = host;
this.socket = socket;
this.address = address;
initFrame();
}
public void run () {
try {
input = new Scanner(socket.getInputStream());
output = new PrintWriter(socket.getOutputStream(), true);
}
catch (IOException ioEx) {
JOptionPane.showMessageDialog(this, "Cannot create input or output stream!", "Error", JOptionPane.ERROR_MESSAGE);
closeSocket();
System.exit(1);
}
do {
clientName = JOptionPane.showInputDialog("What nickname would you like to use in the chatroom?");
} while (clientName == null);
output.println("#" + clientName);
do {
serverResponse = input.nextLine();
serverResponseArea.append(serverResponse + "\n");
} while (socket.isClosed() != true);
}
private final void closeSocket () {
try {
socket.close();
}
catch (IOException ioEx) {
JOptionPane.showMessageDialog(this, "Cannot disconnect from chatroom!", "Error", JOptionPane.ERROR_MESSAGE);
}
}
private void initFrame () {
JMenuBar menuBar = createMenuBar();
setJMenuBar(menuBar);
JScrollPane responsePanel = createResponsePanel();
add(responsePanel, BorderLayout.NORTH);
JPanel messagePanel = createMessagePanel();
add(messagePanel, BorderLayout.CENTER);
//JPanel textPanel = createTextPanel();
//add(textPanel, BorderLayout.SOUTH);
addWindowListener(new WindowAdapter () {
#Override
public void windowClosing (WindowEvent we) {
if (!socket.isClosed())
closeSocket();
System.exit(0);
}
});
}
private JMenuBar createMenuBar () {
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("Operations");
connect = new JMenuItem("Connect");
connect.setEnabled(false);
connect.addActionListener(new ActionListener () {
#Override
public void actionPerformed (ActionEvent event) {
try {
host = InetAddress.getByName(address);
}
catch (UnknownHostException uhEx) {
JOptionPane.showMessageDialog(null, "Unknown Host!", "Error", JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
try {
socket = new Socket(host, MultithreadEchoChatroomClient1.PORT);
}
catch (IOException ioEx) {
JOptionPane.showMessageDialog(null, ioEx.toString(), "Error", JOptionPane.ERROR_MESSAGE);
}
try {
input = new Scanner(socket.getInputStream());
output = new PrintWriter(socket.getOutputStream(), true);
}
catch (IOException ioEx) {
JOptionPane.showMessageDialog(ClientFrame.this, "Cannot create input or output stream!", "Error", JOptionPane.ERROR_MESSAGE);
closeSocket();
System.exit(1);
}
output.println("#" + clientName);
serverResponse = input.nextLine();
serverResponseArea.append(serverResponse + "\n");
}
});
JMenuItem quit = new JMenuItem("Quit");
quit.addActionListener(new ActionListener() {
#Override
public void actionPerformed (ActionEvent event) {
if (!socket.isClosed())
closeSocket();
System.exit(0);
}
});
menu.add(connect);
menu.add(quit);
menuBar.add(menu);
return menuBar;
}
private JScrollPane createResponsePanel () {
serverResponseArea = new JTextArea(20, 35);
serverResponseArea.setEditable(false);
serverResponseArea.setLineWrap(true);
serverResponseArea.setWrapStyleWord(true);
serverResponseArea.setMargin(new Insets(5, 5, 5, 5));
JScrollPane scrlPane = new JScrollPane(serverResponseArea);
scrlPane.setBorder(BorderFactory.createEmptyBorder(20, 10, 10, 20));
scrlPane.setBackground(Color.yellow);
return scrlPane;
}
private JPanel createMessagePanel () {
JPanel msgPanel = new JPanel();
msgPanel.setBorder(BorderFactory.createEmptyBorder(20,10, 10, 20));
msgPanel.setBackground(Color.blue);
msgPanel.setLayout(new BoxLayout(msgPanel, BoxLayout.LINE_AXIS));
JScrollPane srlPanel = createMessageTextPanel();
msgPanel.add(srlPanel);
JButton sdButton = createSendButton();
msgPanel.add(sdButton);
return msgPanel;
}
private JScrollPane createMessageTextPanel () {
messageArea = new JTextArea(10, 35);
//messageArea.setEditable(false);
messageArea.setLineWrap(true);
messageArea.setWrapStyleWord(true);
messageArea.setMargin(new Insets(5, 5, 5, 5));
JScrollPane mtPanel = new JScrollPane(messageArea);
return mtPanel;
}
private JButton createSendButton () {
JButton button = new JButton("Send");
button.addActionListener(new ActionListener() {
#Override
public void actionPerformed (ActionEvent event) {
String message;
message = messageArea.getText();
System.out.println(message);
output.println(message);
if (message.equals("Bye")) {
closeSocket();
connect.setEnabled(true);
}
messageArea.setText("");
//serverResponse = input.nextLine();
//serverResponseArea.append(serverResponse + "\n");
}
});
return button;
}
}
Thank you again for taking so much trouble reading much code and giving suggestions!

The problem is solved according to #user207421. I should have put a remove() operation in the else {} block in the method acceptData(SelectedKey key) so that the old key associated with the socketChannel is removed from the selected key set for new incoming keys to be able to be detected.
I don't know whether my understanding of user207421's solution was right or not, but it did solve the problem for now. If anybody has any other ideas, please share your views.
Thank you again, user207421. And thank all visitors to this post for your attention.

Passing data between class and running thread

Using code examples from stockoverflow I made a class to receive data over TCP/IP.
Class code below. It is working OK and I do receive data from other PC.
recPositions Map is build correctly. After transmission is finished I can display all data I received using getRecPositions()
This thread is started in other class that build simple HMI screen.
Thread runs and display data received from other PC.
Problem is I would like to access same data in MainWindow class (HMI)
but it always show that nothing was received.
Class MainWindow below (not all of it since there is lots of useless pushbuttons and so on)
At the very bottom I have pushbutton that should display how many positions were recorded (elements in Map) but it always show 0.
Code snippet from push button update.
System.out.println(dataServer.getRecPositions().size())
So at some point I am doing something wrong.
Thread starts and runs and I can see incoming positions. At some point after I received "EOT" I display received positions stored in Map. But when I tried to display the size of Map in main window it always show 0.
/*
* Simple data server for receiving string data from IIWA robot
*/
public class SimpleDataServer implements Runnable {
Map<Integer, String> recPositions = new HashMap<>();
Server1Connection oneconnection;
ServerSocket echoServer = null;
Socket clientSocket = null;
int port;
boolean reset = false;
public SimpleDataServer( int port ) {
this.port = port;
}
public void stopServer() {
System.out.println( "Simple data server stopped" );
}
public void startServer() {
// Try to open a server socket on the given port
// Note that we can't choose a port less than 1024 if we are not
// privileged users (root)
try {
echoServer = new ServerSocket(port);
}
catch (IOException e) {
System.out.println(e);
}
System.out.println( "Waiting for connections. Only one connection is allowed." );
// Create a socket object from the ServerSocket to listen and accept connections.
// Use Server1Connection to process the connection.
while ( true ) {
try {
clientSocket = echoServer.accept();
oneconnection = new Server1Connection(clientSocket, this);
oneconnection.run();
if(isReset()) {
setReset(false);
System.out.println("Recording finished");
System.out.println("DEBUG:" + this.getRecPositions().size() + " positions recorded: " + this.getRecPositions());
}
}
catch (IOException e) {
System.out.println(e);
}
}
}
#Override
public void run() {
int port = this.port;
SimpleDataServer server = new SimpleDataServer( port );
server.startServer();
}
public Map<Integer, String> getRecPositions() {
return recPositions;
}
public void setRecPositions(Map<Integer, String> recPositions) {
this.recPositions = recPositions;
}
public boolean isReset() {
return reset;
}
public void setReset(boolean reset) {
this.reset = reset;
}
}
class Server1Connection {
BufferedReader is;
PrintStream os;
Socket clientSocket;
SimpleDataServer server;
public Server1Connection(Socket clientSocket, SimpleDataServer server) {
this.clientSocket = clientSocket;
this.server = server;
System.out.println( "Connection established with: " + clientSocket );
try {
is = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
os = new PrintStream(clientSocket.getOutputStream());
} catch (IOException e) {
System.out.println(e);
}
}
public Map<Integer, String> getPositions() {
return server.getRecPositions();
}
public void run() {
String line; //whole line recevied
String segment = null; //single segment from line using comma delimiter
List<String> stringsList;
try {
boolean serverStop = false;
//server runs here
while (true)
{
line = is.readLine();
System.out.println( "DEBUG Server Received: " + line );
//check is string is not empty
if (line.equals(null)) {
System.err.println("Empty String received");
break;
}
stringsList = new ArrayList<String>(Arrays.asList(line.split(";")));
if (!stringsList.isEmpty()) {
stringsList.set(0, stringsList.get(0).replaceAll("\\s+",""));
stringsList.set((stringsList.size()-1), stringsList.get(stringsList.size()-1).replaceAll("\\s+",""));
String lastSegment = stringsList.get((stringsList.size()-1));
if (lastSegment.equals("ETX") || lastSegment.equals("EOT")) {
switch (stringsList.get(0)) {
case "MSG":
stringsList.remove(0);
stringsList.remove(stringsList.size()-1);
System.out.println("Message: " + stringsList.toString());
break;
case "POS":
// for (String blah : stringsList) {
// System.out.println("DEBUG" + blah);
// }
iiwaPosfromString iiwaPos = new iiwaPosfromString(stringsList.get(1), stringsList.get(2));
System.out.println("DEBUG Position number: " + iiwaPos.posNum + " ; " + iiwaPos.toString());
if (iiwaPos.getPosNum() > 0) {
server.getRecPositions().put(iiwaPos.getPosNum(), iiwaPos.toString());
}
break;
case "EOT":
case "EXT":
//ignore handled later
break;
default:
System.err.println("Ausgebombt!");
break;
}
}
//ETX End Of Text - dump data to screen - close current connection
if(lastSegment.equals("ETX")) {
System.out.println("End of Text received");
break;
}
//EOT End Of Transmission - shuts down server
if(lastSegment.equals("EOT")) {
System.out.println("End of Transmission received");
serverStop = true;
server.setReset(true);
break;
}
System.err.println("No correct end string!");
try {
Thread.sleep(500);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
break;
} else {
System.out.println("Empty String received");
break;
}
}
System.out.println( "Connection closed." );
is.close();
os.close();
clientSocket.close();
if ( serverStop ) server.stopServer();
} catch (IOException e) {
System.out.println(e);
}
}
public class iiwaPosfromString {
private double posX;
private double posY;
private double posZ;
private double posA;
private double posB;
private double posC;
private int posNum;
public iiwaPosfromString(String posNum, String posString) {
List <String>stringsList = new ArrayList<String>(Arrays.asList(posString.split(" ")));
for (int i = 0; i < stringsList.size(); i++) {
String newElement = stringsList.get(i);
newElement = newElement.replaceAll("[^\\d.]", "");
stringsList.set(i, newElement);
}
this.setPosNum(Integer.parseInt(posNum));
this.setPosX(Double.parseDouble(stringsList.get(1)));
this.setPosY(Double.parseDouble(stringsList.get(2)));
this.setPosZ(Double.parseDouble(stringsList.get(3)));
//this is stupid and don't do that
//from right to left, string to double, change radians to degrees, format to two decimals(string), string to double again
this.setPosA(Double.parseDouble(String.format("%.2f",(Math.toDegrees(Double.parseDouble(stringsList.get(4)))))));
this.setPosB(Double.parseDouble(String.format("%.2f",(Math.toDegrees(Double.parseDouble(stringsList.get(4)))))));
this.setPosC(Double.parseDouble(String.format("%.2f",(Math.toDegrees(Double.parseDouble(stringsList.get(4)))))));
}
public double getPosX() {
return posX;
}
public void setPosX(double posX) {
this.posX = posX;
}
public double getPosY() {
return posY;
}
public void setPosY(double posY) {
this.posY = posY;
}
public double getPosZ() {
return posZ;
}
public void setPosZ(double posZ) {
this.posZ = posZ;
}
public double getPosA() {
return posA;
}
public void setPosA(double posA) {
this.posA = posA;
}
public double getPosB() {
return posB;
}
public void setPosB(double posB) {
this.posB = posB;
}
public double getPosC() {
return posC;
}
public void setPosC(double posC) {
this.posC = posC;
}
#Override
public String toString() {
return "<" +
"X: " + getPosX() + ", " +
"Y: " + getPosY() + ", " +
"Z: " + getPosZ() + ", " +
"A: " + getPosA() + ", " +
"B: " + getPosB() + ", " +
"C: " + getPosC() +
">";
}
public int getPosNum() {
return posNum;
}
public void setPosNum(int posNum) {
this.posNum = posNum;
}
}
}
public class MainWindow {
private Thread dataServerThread;
private SimpleDataServer dataServer;
private XmlParserGlobalVarsRD globalVarPLC, globalVarKRC;
private JFrame frame;
private JTextField simpleWorkingDirStiffness;
private JTextField simpleWorkingDirAdditionalForce;
private JTextField simpleTravelDistance;
private JTextField simpleTravelVelocity;
private JTextField simpleTotalTime;
private JTextField simpleTheoreticalDepth;
private JTextField simpleZProgress;
private JComboBox oscillationMode;
/**
* Launch the application.
*/
public static void main(String[] args) {
try {
UIManager.setLookAndFeel("javax.swing.plaf.nimbus.NimbusLookAndFeel");
} catch (Throwable e) {
e.printStackTrace();
}
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
MainWindow window = new MainWindow();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public MainWindow() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
final JCheckBox emptyScanCycle = new JCheckBox("VRSI Scan Cycle Plain Fasteners");
//set data server thread and start it
dataServer = new SimpleDataServer(30008);
dataServerThread = new Thread(dataServer);
dataServerThread.setDaemon(true);
dataServerThread.start();
...
JButton pbUpdate = new JButton("UPDATE");
pbUpdate.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
System.out.println(dataServer.getRecPositions().size())
}
});
pbUpdate.setBounds(210, 176, 90, 28);
frame.getContentPane().add(pbUpdate);
}

I believe the issue is in your SimpleDataServer.run method. You are creating a separate instance of SimpleDataServer from WITHIN your SimpleDataServer instance. Therefore, all of the communication is taking place in an object that your MainWindow has no direct reference to. I believe your SimpleDataServer.run method should look like this:
#Override
public void run() {
this.startServer();
}

How do I select which stream to close out of multiple streams?

I didn't realize until now that my disconnect button on my program was failing. If I have 3 clients up, and any of them click disconnect, then only the last client gets disconnected. How do I select which instance I need to close? If out of the 3 users I want to remove the first one..
server:
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.HashSet;
import java.util.Scanner;
import java.util.Set;
public class Server {
private Set<Socket> sockets = new HashSet<Socket>();
private Set<String> names = new HashSet<String>();
private Socket sock;
private static int port;
private Calendar cal = Calendar.getInstance();
private SimpleDateFormat date = new SimpleDateFormat("dd/mm/yyyy hh:mm:ss");
public Server(int input) {
port = input;
}
public static void main(String[] args) {
/*
* user defines port number, server initialized
*/
System.out.println("enter a port");
Scanner input = new Scanner(System.in);
port = input.nextInt();
new Server(port).go();
input.close();
}
public void go() {
try {
/*
* wait for connections, add connections to Set, setup streams per
* connection in new threads
*/
System.out.println("waiting for connetion");
#SuppressWarnings("resource")
ServerSocket serverSocket = new ServerSocket(port);
while (true) {
sock = serverSocket.accept();
sockets.add(sock);
Thread t = new Thread(new ClientHandler(sock));
t.start();
System.out.println("connected: " + sock.getInetAddress());
}
} catch (IOException ex) {
ex.printStackTrace();
System.out.println("server setup failed");
}
}
class ClientHandler implements Runnable {
/*
* client handler sets up streams
*/
private BufferedReader in;
private PrintWriter out;
private String name;
public ClientHandler(Socket sock) {
try {
in = new BufferedReader(new InputStreamReader(
sock.getInputStream()));
out = new PrintWriter(sock.getOutputStream(), true);
} catch (IOException e) {
e.printStackTrace();
System.out.println("stream setup failed");
}
}
#Override
public void run() {
/*
* First check if user exists, if true than close connection and
* warn user about name. Then relay message to all clients, if user
* DC's than remove the socket from the Set
*/
String message;
try {
name = in.readLine();
if (names.contains(name)) {
System.out.println("duplicate name detected, removing..");
out.println("choose new name and reconnect: "
+ sock.getInetAddress());
sock.close();
sockets.remove(sock);
} else {
names.add(name);
System.out.println("Users active: " + names);
shout("user: " + name + " connected!" + " from "
+ sock.getInetAddress());
}
while ((message = in.readLine()) != null) {
/*
* call method which checks if user tries to enter a command
* such as /laugh or /roll, otherwise relay the message to
* all clients
*/
swich(message);
}
} catch (IOException ex) {
System.out.println("user disconnected: " + name + " "
+ sock.getInetAddress());
shout("user disconnected: " + name + " "
+ sock.getInetAddress());
names.remove(name);
remove(sock);
}
}
public synchronized void shout(String message) {
// send message to all clients in Set
for (Socket sock : sockets) {
try {
PrintWriter writer = new PrintWriter(
sock.getOutputStream(), true);
writer.println(date.format(cal.getTime()) + " " + message
+ "\n");
} catch (IOException e) {
e.printStackTrace();
}
}
}
public void swich(String message) throws IOException {
// check if user calls a chat command
// otherwise shout message to all clients
switch (message) {
case "/disconnect":
out.println("disconnected");
remove(sock);
break;
case "/laugh":
String[] laughs = { "HahHA!", "HAHAAH!!!!", "haaaaa!!!",
"hohohoohohahhaa!!!", "huehuehue!" };
shout(name + " " + laughs[(int) (Math.random() * 5)]);
break;
case "/roll":
shout(name + " rolls "
+ Integer.toString((int) ((Math.random() * 6) + 1)));
break;
case "kirby!":
shout("(>'-')> <('-'<) ^(' - ')^ <('-'<) (>'-')>");
break;
default:
shout(message);
System.out.println("client says : "
+ date.format(cal.getTime()) + message);
}
}
}
public void remove(Socket soc) {
try {
soc.close();
sockets.remove(soc);
} catch (IOException e) {
e.printStackTrace();
}
}
}
client:
import java.awt.BorderLayout;
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.Scanner;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class Client {
private JTextArea tArea;
private JTextField tField;
private JTextField portText;
private JTextField hostText;
private BufferedReader in;
private Socket sock;
private static PrintWriter out;
private static String name;
private String host;
private String port;
public static void main(String[] args) {
System.out.println("Enter username");
Scanner input = new Scanner(System.in);
name = input.nextLine();
input.close();
new Client().go();
}
public void go() {
/*
* build gui
*/
SwingUtilities.invokeLater(new Runnable() {
public void run() {
JFrame frame = new JFrame("hakobChat");
JPanel topPanel = new JPanel();
JLabel portLabel = new JLabel("port");
JLabel hostLabel = new JLabel("host");
portText = new JTextField(6);
hostText = new JTextField(12);
JButton connect = new JButton("connect");
connect.addActionListener(new connectListener());
JButton disconnect = new JButton("disconnect");
disconnect.addActionListener(new disconnectListener());
tField = new JTextField(30);
tField.addActionListener(new sendListener());
tArea = new JTextArea(30, 50);
tArea.setEditable(false);
tArea.setLineWrap(true);
JScrollPane tScroll = new JScrollPane(tArea,
JScrollPane.VERTICAL_SCROLLBAR_ALWAYS,
JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
JButton button = new JButton("send");
button.addActionListener(new sendListener());
topPanel.add(hostLabel);
topPanel.add(hostText);
topPanel.add(portLabel);
topPanel.add(portText);
topPanel.add(connect);
topPanel.add(disconnect);
frame.setSize(300, 500);
frame.setVisible(true);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.getContentPane().add(topPanel, BorderLayout.NORTH);
frame.getContentPane().add(tScroll, BorderLayout.CENTER);
frame.getContentPane().add(tField, BorderLayout.SOUTH);
frame.getContentPane().add(button, BorderLayout.EAST);
frame.pack();
}
});
}
public void setupNetwork(String host, int port) {
/*
* setup in and out stream send user name to server to check if
* duplicate start thread for incoming messages
*/
try {
sock = new Socket(host, port);
in = new BufferedReader(
new InputStreamReader(sock.getInputStream()));
out = new PrintWriter(sock.getOutputStream(), true);
out.println(name);
showMessage("Connected!");
showMessage("enter /laugh or /roll or kirby! for some fun!");
Thread t = new Thread(new IncomingReader());
t.start();
} catch (IOException ex) {
ex.printStackTrace();
showMessage("please enter valid network");
}
}
class IncomingReader implements Runnable {
// receive messages from server
public void run() {
try {
String message = null;
while ((message = in.readLine()) != null) {
showMessage(message + "\n");
}
} catch (Exception e) {
e.printStackTrace();
showMessage("choose new name and reconnect please");
}
}
}
public synchronized void sendMessage(String message) {
try {
switch (message) {
case "/laugh":
out.println("/laugh");
break;
case "/roll":
out.println("/roll");
break;
case "kirby!":
out.println("kirby!");
break;
default:
out.println("(" + name + ")" + ": " + message);
}
} catch (Exception e) {
e.printStackTrace();
System.out.println("fail send message");
}
}
public void showMessage(final String message) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
tArea.append(message + "\n");
tArea.setCaretPosition(tArea.getDocument().getLength());
// SetCaretPosition forces autos scroll
}
});
}
class sendListener implements ActionListener {
// listens for user to trying to send a message
public void actionPerformed(ActionEvent ev) {
sendMessage(tField.getText());
tField.setText("");
}
}
class disconnectListener implements ActionListener {
public void actionPerformed(ActionEvent ev) {
try {
out.println("/disconnect");
} catch (NullPointerException e) {
showMessage("not connected");
}
}
}
class connectListener implements ActionListener {
public void actionPerformed(ActionEvent ev) {
host = hostText.getText();
port = portText.getText();
if (!host.equals("") && !port.equals("") && port.matches("[1-9]+")) {
// make sure user enters valid inputs
// before setting up network
setupNetwork(host, Integer.parseInt(port));
} else {
showMessage("enter valid network credentials");
}
}
}
}
Also, how do I avoid this "#SuppressWarnings("resource")". If I don't have this eclipse provided warning than the serverSocket is underlined yellow.

You need to save a the Socket used for the client inside of the ClientHandler.
You can do this by simply adding a
private Socket sock;
inside of ClientHandler, and adding:
this.sock = sock;
inside of its constructor.
Currently you're using the Socket saved in the server, which will always be the socket of the last client that connected, rather than the Socket belonging to the current client.

This is just a scoping problem. The Socket sock member shouldn't be part of the Server class. It should be part of the ClientHandler class. One per client.

Java Multi-Client Chat Application - Sending messages issue

My problem is, I can still send messages between Clients(Client-to-Client) but after sending two or three times, messages are no more displayed to the recipient.
So basically whenever the Client wish to send a message to another Client, the message is first sent to the server. But as you have noticed from my coding, I am sending the server data in form of an object.
For example:
send(new ChatMessage(type, sender, content, recipient));
When you send a message the type is "message". When the server receives the object, it checks the receive data and its type.
For example:
ChatMessage cm = (ChatMessage) in[client[id].readObject();
if(cm.type.equals("message"){
send(findUserThread(toWhom), new ChatMessage("message", sender, content, recipient);
}
If the type is "message", then it sends that specific client the message.
I am using System.out.println() at the Client side to see the incoming data from server. So when I try to send some messages, it is working fine but then after sending some messages nothing is display on my chat screen.
According to my logic the errors can be:
1 Selected index in JList
2 Client[] array or username[] array
3 ObjectOutputStream and ObjectInputStream
ServerGUI class(Server Side)
package test2;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.*;
import java.util.zip.GZIPOutputStream;
import javax.swing.SwingUtilities;
public class ServerGUI extends JFrame implements ActionListener {
public JList online;
private JTextField ipaddress, textMessage;
private JButton send, start, disconnect;
private JTextArea chatArea;
private JLabel port;
int client[] = new int[100];
private ObjectOutputStream out[] = new ObjectOutputStream[client.length + 1];
private ObjectInputStream in[] = new ObjectInputStream[client.length + 1];
String username[] = new String[client.length + 1];
static String b;
public String nm, usm;
private ServerSocket server;
private Socket connect;
boolean success = true;
int id = 0;
ArrayList<String> UserList = new ArrayList<String>();
public ServerGUI() {
Container c = getContentPane();
c.setLayout(new BorderLayout());
c.setPreferredSize(new Dimension(650, 500));
JPanel p = new JPanel();
p.setLayout(new FlowLayout());
p.setBackground(Color.LIGHT_GRAY);
p.add(port = new JLabel("Port No"));
p.add(ipaddress = new JTextField("1500"));
p.add(start = new JButton("START"));
p.add(disconnect = new JButton("DISCONNECT"));
disconnect.setEnabled(false);
start.setBorderPainted(false);
start.setBackground(Color.blue);
start.setForeground(Color.WHITE);
disconnect.setBorderPainted(false);
disconnect.setBackground(Color.blue);
disconnect.setForeground(Color.WHITE);
ipaddress.setCaretPosition(0);
JPanel p1 = new JPanel();
p1.setLayout(new FlowLayout());
p1.setBackground(Color.LIGHT_GRAY);
p1.add(chatArea = new JTextArea());
chatArea.setPreferredSize(new Dimension(300, 350));
chatArea.setLineWrap(true);
chatArea.setEditable(false);
JPanel p2 = new JPanel();
p2.setLayout(new FlowLayout());
p2.setBackground(Color.LIGHT_GRAY);
p2.add(textMessage = new JTextField(20));
p2.add(send = new JButton("SEND"));
send.setBackground(Color.blue);
send.setForeground(Color.WHITE);
send.setBorderPainted(false);
start.addActionListener(this);
send.addActionListener(this);
c.add(p, BorderLayout.NORTH);
c.add(p1, BorderLayout.CENTER);
c.add(p2, BorderLayout.SOUTH);
}
//current time
SimpleDateFormat log = new SimpleDateFormat("HH:mm");
String d = log.format(new Date());
//Start server
public void Start() {
int portNo = 0;
try {
String no = ipaddress.getText();
portNo = Integer.parseInt(no);
chatArea.append("Connection to port " + portNo + "...\n");
server = new ServerSocket(portNo);
success = true;
} catch (Exception ex) {
chatArea.append("Error cannot bind to port \n");
success = false;
}
if (success == true) {
addClient ob1 = new addClient("RunServer");
start.setEnabled(false);
disconnect.setEnabled(true);
}
}
public class addClient implements Runnable {
Thread t;
addClient(String tot) {
t = new Thread(this, tot);
t.start();
}
public void run() {
while (true) {
try {
try {
WaitClient();
} catch (Exception ex) {
break;
}
for (int i = 0; i < client.length; i++) {
if (client[i] == 0) {
client[i] = i + 1;
id = i;
break;
}
}
//set stream to send and receive data
out[client[id]] = new ObjectOutputStream(connect.getOutputStream());
out[client[id]].flush();
in[client[id]] = new ObjectInputStream(connect.getInputStream());
chatArea.append(d + " Client:[" + client[id] + "] : Connected successful \n");
chatArea.setCaretPosition(chatArea.getText().length());
//inform user that connection is successfull
ChatMessage cm = (ChatMessage) in[client[id]].readObject(); // read client username
if(cm.type.equals("login")){
chatArea.append("User " +cm.sender + " connected successfully" + "\n" );
username[client[id]] = cm.sender;
System.out.println(username[0]+ username[1]+ username[2]);
send(client[id], new ChatMessage("login", username[client[id]], "user", "SERVER"));
sendUserList(cm.sender);
Announce("newuser", "SERVER", cm.sender);
}
Chat c = new Chat(client[id], "StartChat" + client[id]); // make new thread for every new client
} catch (Exception e) {
e.printStackTrace();
}
}
}
}
public class Chat implements Runnable {
int id1;
Chat ob1;
Thread t;
Chat(int id1, String info1) {
this.id1 = id1; // create a thread for client
t = new Thread(this, info1);
t.start();
}
public void run() {
boolean running = true;
while(running){
try {
ChatMessage cm = (ChatMessage) in[client[id]].readObject(); // read client username
if(cm.type.equals("message")){
send(findUserThread(cm.recipient), new ChatMessage(cm.type, cm.sender, cm.content, cm.recipient));
}
} catch (Exception e) {
}
}
}
}
//wait for connection, then display connection information
private void WaitClient() throws IOException {
chatArea.append(d + " : Waiting for connection... \n");
connect = server.accept();
chatArea.append(d + " : Now connected to " + connect.getInetAddress().getHostName() + "\n");
}
//send message to specific user
public void sendUser(int number, String info) {
try {
out[number].writeObject(info);
out[number].flush();
} catch (Exception e) {
}
}
public void sendServer(String por) {
for (int i = 0; i < client.length; i++) // for loop trying to send message from server to all clients
{
if (client[i] != 0) // this line stop server to send messages to offline clients
{
try {
out[i + 1].writeObject(por);
out[i + 1].flush();
} catch (Exception e) {
}
}
}
}
public void Announce(String type, String sender, String content){
ChatMessage cm = new ChatMessage(type, sender, content, "All");
for(int i = 0; i < id; i++){
send(client[i], cm);
}
}
public void send(int number, ChatMessage cm) {
try {
out[number].writeObject(cm);
out[number].flush();
} catch (Exception e) {
}
}
void sendAll(int num, String por) {
for (int i = 0; i < client.length; i++) // for loop trying to send message from server to all clients
{
if (client[i] != 0) // this line stop server to send messages to offline clients (if "clientNiz[X] = 0" don't try to send him message, because that slot is empty)
{
if (num != i + 1) // don't repeat messages (when for ex. client_1 send message to all clients, this line stop server to send same message back to client_1)
{
try {
out[i + 1].writeObject(por);
out[i + 1].flush();
} catch (Exception e) {
}
}
}
}
}
public void sendUserList(String toWhom){
for(int i = 0; i <= id; i++){
send(findUserThread(toWhom), new ChatMessage("newuser", "SERVER", username[client[i]], toWhom));
}
}
public int findUserThread(String usr){
for(int i = 0; i <= id; i++){
if(username[client[i]].equals(usr)){
return client[i];
}
}
return -1;
}
private int findClient(int num){
for (int i = 0; i <= id; i++){
if (client[i] == (num+1)){
return i;
}
}
return -1;
}
public void actionPerformed(ActionEvent e) {
if (e.getSource() == send) {
//current time
String s1 = textMessage.getText();
send(client[id], new ChatMessage("message", "admin", s1, "client"));
chatArea.append("Administrator: " + s1 + "\n");
} else if (e.getSource() == start) {
Start();
}
if (e.getSource() == disconnect) {
try {
server.close();
} catch (Exception ex) {
}
for (int i = 0; i < client.length; i++) {
try {
in[i].close();
out[i].close();
} catch (Exception ex) {
}
}
chatArea.append("Server is disconnected\n");
start.setEnabled(true);
disconnect.setEnabled(false);
}
}
}
MainGUI class(Client Side)
package test2;
import java.io.*;
import java.net.*;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Date;
import java.io.BufferedOutputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import javax.swing.DefaultListModel;
import javax.swing.JFileChooser;
public class MainGUI extends javax.swing.JFrame {
public MainGUI() {
initComponents();
}
#SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jButton1 = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
start = new javax.swing.JButton();
jLabel2 = new javax.swing.JLabel();
textMessage = new javax.swing.JTextField();
jScrollPane2 = new javax.swing.JScrollPane();
chatArea = new javax.swing.JTextArea();
usernm = new javax.swing.JTextField();
jLabel1 = new javax.swing.JLabel();
send = new javax.swing.JButton();
upload = new javax.swing.JButton();
filename = new javax.swing.JTextField();
jScrollPane1 = new javax.swing.JScrollPane();
online = new javax.swing.JList();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("ICARE ");
setFocusable(false);
setPreferredSize(new java.awt.Dimension(840, 650));
setResizable(false);
getContentPane().setLayout(null);
jButton1.setText("Video Call");
getContentPane().add(jButton1);
jButton1.setBounds(270, 10, 100, 30);
jButton3.setText("Send");
jButton3.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jButton3ActionPerformed(evt);
}
});
getContentPane().add(jButton3);
jButton3.setBounds(690, 100, 100, 30);
start.setBackground(new java.awt.Color(51, 51, 255));
start.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
start.setForeground(new java.awt.Color(255, 255, 255));
start.setText("Start");
start.setBorder(null);
start.setBorderPainted(false);
start.setRequestFocusEnabled(false);
start.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
startActionPerformed(evt);
}
});
getContentPane().add(start);
start.setBounds(630, 50, 90, 40);
getContentPane().add(jLabel2);
jLabel2.setBounds(0, 0, 820, 0);
getContentPane().add(textMessage);
textMessage.setBounds(270, 450, 420, 70);
chatArea.setColumns(20);
chatArea.setFont(new java.awt.Font("Arial", 0, 14)); // NOI18N
chatArea.setRows(5);
jScrollPane2.setViewportView(chatArea);
getContentPane().add(jScrollPane2);
jScrollPane2.setBounds(270, 140, 520, 300);
getContentPane().add(usernm);
usernm.setBounds(450, 60, 170, 30);
jLabel1.setFont(new java.awt.Font("Tahoma", 1, 14)); // NOI18N
jLabel1.setText("Enter your nickname:");
getContentPane().add(jLabel1);
jLabel1.setBounds(270, 60, 150, 30);
send.setBackground(new java.awt.Color(51, 51, 255));
send.setFont(new java.awt.Font("Tahoma", 0, 14)); // NOI18N
send.setForeground(new java.awt.Color(255, 255, 255));
send.setText("Send");
send.setBorder(null);
send.setBorderPainted(false);
send.setRequestFocusEnabled(false);
send.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
sendActionPerformed(evt);
}
});
getContentPane().add(send);
send.setBounds(700, 470, 90, 40);
upload.setFont(new java.awt.Font("Tahoma", 0, 18)); // NOI18N
upload.setText("+");
upload.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
uploadActionPerformed(evt);
}
});
getContentPane().add(upload);
upload.setBounds(633, 100, 50, 30);
getContentPane().add(filename);
filename.setBounds(270, 100, 350, 30);
jScrollPane1.setViewportView(online);
getContentPane().add(jScrollPane1);
jScrollPane1.setBounds(30, 20, 220, 500);
pack();
}// </editor-fold>
private void startActionPerformed(java.awt.event.ActionEvent evt) {
Start();
}
private void sendActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
String z = textMessage.getText();
String target = online.getSelectedValue().toString();
chatArea.append("[ " + usernm.getText() + " ] : " + z + "\n");
send(new ChatMessage("message", usernm.getText(), z, target));
textMessage.setText("");
}
private void uploadActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
//Create a file chooser
//In response to a button click:
JFileChooser fileChooser = new JFileChooser();
fileChooser.showDialog(this, "Select File");
file = fileChooser.getSelectedFile();
if(file != null){
if(!file.getName().isEmpty()){
String str;
if(filename.getText().length() > 30){
String t = file.getPath();
str = t.substring(0, 20) + " [...] " + t.substring(t.length() - 20, t.length());
}
else{
str = file.getPath();
}
filename.setText(str);
}
}
}
private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
long size = file.length();
if(size < 120 * 1024 * 1024){
sendUser("download");
}
else{
chatArea.append("File is size too large\n");
}
}
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/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(MainGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MainGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MainGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MainGUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new MainGUI().setVisible(true);
}
});
}
// Variables declaration - do not modify
public javax.swing.JTextArea chatArea;
private javax.swing.JTextField filename;
private javax.swing.JButton jButton1;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JScrollPane jScrollPane2;
public javax.swing.JList online;
private javax.swing.JButton send;
private javax.swing.JButton start;
private javax.swing.JTextField textMessage;
private javax.swing.JButton upload;
private javax.swing.JTextField usernm;
// End of variables declaration
private ObjectOutputStream out;
private ObjectInputStream in;
static String b; //variable for message
private Socket join;
boolean success = true;
private String serverIP = "127.0.0.1"; //set IP Address
ArrayList<String> userlist = new ArrayList<String>(); //ArrayList to store online users
//current time
SimpleDateFormat log = new SimpleDateFormat("HH:mm");
String d = log.format(new Date());
public File file;
public DefaultListModel model = new DefaultListModel();
//Start client program
public void Start() {
try {
start.setEnabled(false);
chatArea.append(d + " : Attempting connection... \n");
join = new Socket(serverIP, 10500);
chatArea.append(d + " : Connected to - " + join.getInetAddress().getHostName() + "\n");
success = true;
} catch (Exception ex) {
chatArea.append("Error cannot bind to port \n");
success = false;
}
if (success == true) {
ClientThread ct = new ClientThread();
}
}
class ClientThread implements Runnable {
ClientThread ct;
Thread t;
ClientThread() {
t = new Thread(this, "RunClient");
t.start();
}
public void run() {
try {
try {
out = new ObjectOutputStream(join.getOutputStream());
out.flush();
in = new ObjectInputStream(join.getInputStream());
send(new ChatMessage("login", usernm.getText(), "password", "SERVER"));
} catch (Exception e) { }
CThread c1 = new CThread();
} catch (Exception ex) { }
}
}
class CThread implements Runnable {
CThread ob1;
Thread t;
CThread() {
t = new Thread(this, "Message");
t.start();
}
public void run() {
boolean running = true;
try {
while(running){
try {
ChatMessage cm = (ChatMessage) in.readObject();
System.out.println("Incoming :" + cm.toString());
if(cm.type.equals("login")){
chatArea.append(cm.sender + " is online" + "\n");
}else if(cm.type.equals("message")){
if(cm.recipient.equals(usernm.getText())){
chatArea.append("[ "+cm.sender +" ] : " + cm.content + "\n");
}
}else if(cm.type.equals("newuser")){
online.setModel(model);
model.addElement(cm.content);
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
} catch (Exception ex) {
}
}
}
void sendUser(String por) {
try {
out.writeObject(por);
out.flush();
} catch (Exception e) {
}
}
void send(ChatMessage cm){
try {
out.writeObject(cm);
out.flush();
} catch (Exception e) {
}
}
}
ChatMessage class
package test2;
import java.io.Serializable;
public class ChatMessage implements Serializable{
private static final long serialVersionUID = 1L;
public String type, sender, content, recipient;
public ChatMessage(String type, String sender, String content, String recipient){
this.type = type; this.sender = sender; this.content = content; this.recipient = recipient;
}
#Override
public String toString(){
return "{type='"+type+"', sender='"+sender+"', content='"+content+"', recipient='"+recipient+"'}";
}
}
ServerTest to run ServerGUI
public class ServerTest
{
public static void main(String args[]){
ServerGUI m = new ServerGUI();
m.setTitle("Server");
m.setVisible(true);
m.pack();
//to make to the center of the screen
m.setLocationRelativeTo(null);
}
}

Classes in Java should start with uppercase. For example: ServerGUI but not addClient as seen in your code.
Classes represent objects. Or "classes" of objects. For example Car or ServerGUI but not addClient. What is an new addClient()? Is that an object really?
Variable names should have significant names if possible. For example Car limousine = new Car(4,Color.Black) and not addClient ob1 = new addClient("RunServer"). What does ob1 mean?
Comments are fresh air for readers. Please, use comments. For example: //we are going to represent the server as a special user with admin privileges
Method names ir Java should not start with uppercase. This is a bad example: private void WaitClient() throws IOException
Indent and blank lines. Don't know if it is your fault partly or completely but the code is bad indented, has blank lines inside blocks (not just one or two, nor acting as separator), and misses spaces (if(cm.type.equals("login")){)
StackOverflow is not a good place for your problem. Here people ask specific questions. Yours is not a specific question, it is more a "my program doesn't work" problem.
In conclusion: your code is hard to read and understand. It seems you are new to Java so please, start with simple and easy examples, use a Java IDE like Eclipse or Netbeans and take your time! You won't learn Java in a week, be patient.
Sorry if I've been too honest but that's what I think (and probably one of the reasons nobody else here is helping you).

But after sending two or three messages, my program stop sending messages
First of all you should try to debug your application. Using logs or System.out.println you can easily find out where is it "stopping". Is the message being sent to the server? Is the server sending the message to the client? You can answer these questions with just a few println.
Once you know where (in your code, which method) it is failing you can post a more specific question if you still need help.
Also when you have a problem, please explain what problem it is really, in detail. Does the application crash? Does it stop sending messages to everybody? "my program stops sending messages" is a little bit vague.
EDIT: Well, now that I see the code, please, do not do this:
void send(ChatMessage cm){
try {
out.writeObject(cm);
out.flush();
} catch (Exception e) {
}
}
If an exception is thrown, you won't notice.
You should add:
e.printStackTrace();
inside every catch() block so you can see errors in console when they occur.
Nobody likes red messages in console, but hiding them is not going to help. Always print errors, or log them, or both :)

Starting a thread in a Swing event

I'm working on the client side application of the client/server chat I'm doing for learning experience. My problem is I can't seem to get the socket and swing,both to run at the same time.
What I want to is, when the user opens a JOpionsPane and enters the hostname and port number, clicks okay, then they are connected. When the socket information was hardcoded it worked fine, but now I'm trying to get the users input for it.
What's meant to happen is, action listener is supposed to create the new SocketManager object that handles communication. Event though it says it's connected, it doesn't run. When I create the new SocketManager object and run it on a new thread it connects and revives messages form the server, but then the swings freezes and I have to end the process to shut it down.
Should I start it on a new worker thread or something? Maybe it's just because I'm tired, but I'm out of ideas.
EDIT
I updated my ActLis.class and SocketManager.class with the suggestion of adding a new thread for my SocketManager object 'network'. When I try and use 'network' though it returns null for some reason.
ActLis.clss
package com.client.core;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JComponent;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
public class ActLis implements ActionListener {
private Main main = new Main();;
private JTextField ipadress = new JTextField(),
portnumber = new JTextField(),
actionField;
private String username;
final JComponent[] ipinp = new JComponent[]{new JLabel("Enter Hostname (IP Adress): "),
ipadress,
new JLabel("Enter Port number: "), portnumber};
private SocketManager network;
private Window win;
public ActLis(){
}
public ActLis(JTextField t, Window w){
actionField = t;
win = w;
}
#Override
public void actionPerformed(ActionEvent e) {
String cmd = e.getActionCommand();
if(cmd == "Exit"){
System.exit(0);
} else if(cmd == "Connect to IP"){
try{
JOptionPane.showMessageDialog(null, ipinp, "Connect to IP", JOptionPane.PLAIN_MESSAGE);
if(network != null){
network.close();
}
network = new SocketManager(ipadress.getText(),Integer.parseInt(portnumber.getText()));
network.setGUI(win);
Thread t = new Thread(network);
t.start();
JOptionPane.showMessageDialog(null, "Connected to chat host successfully!","Connected", JOptionPane.INFORMATION_MESSAGE);
}catch(Exception ee){
JOptionPane.showMessageDialog(null, "Could not connect. Check IP adress or internet connection","Error - Could not connect", JOptionPane.ERROR_MESSAGE);
ee.printStackTrace();
}
} else if (cmd == "chatWriter"){
if( actionField.getText() != ""){
try{
network.send(actionField.getText());
win.updateChat(actionField.getText());
actionField.setText("");
actionField.requestFocus();
}catch(Exception ex){
JOptionPane.showMessageDialog(null, "You are not connected to a host. (File -> Connect to IP)","Error - Not Connected", JOptionPane.ERROR_MESSAGE);
ex.printStackTrace();
}
}
} else if (cmd == "setUsername"){
username = actionField.getText();
network.send("USERNAME:" + username);
}
}
}
Main.class
package com.client.core;
import javax.swing.JFrame;
public class Main extends JFrame{
private SocketManager network;
public static void main(String[] args){
Main main = new Main();
main.run();
}
private void run(){
Window win = new Window();
win.setVisible(true);
}
}
SocketManager.class
package com.client.core;
import java.io.*;
import java.net.*;
public class SocketManager implements Runnable {
private Socket sock;
private PrintWriter output;
private BufferedReader input;
private String hostname;
private int portnumber;
private String message;
private Window gui;
public SocketManager(String ip, int port){
try{
hostname = ip;
portnumber = port;
}catch(Exception e){
System.out.println("Client: Socket failed to connect.");
}
}
public synchronized void send(String data){
try{
//System.out.println("Attempting to send: " + data);
output.println(data);
output.flush();
//System.out.println("Message sent.");
}catch(Exception e){
System.out.println("Message could not send.");
}
}
public synchronized void setGUI(Window w){
gui = w;
}
public synchronized void connect(){
try{
sock = new Socket(hostname,portnumber);
}catch(Exception e){
}
}
public synchronized Socket getSocket(){
return sock;
}
public synchronized void setSocket(SocketManager s){
sock = s.getSocket();
}
public synchronized void close(){
try{
sock.close();
}catch(Exception e){
System.out.println("Could not close connection.");
}
output = null;
input = null;
System.gc();
}
public synchronized boolean isConnected(){
return (sock == null) ? false : (sock.isConnected() && !sock.isClosed());
}
public synchronized void listenStream(){
try {
while((message = input.readLine()) != null){
System.out.println("Server: " + message);
gui.updateChat(message);
}
} catch (Exception e) {
}
}
#Override
public void run() {
try {
sock = new Socket(hostname,portnumber);
output = new PrintWriter(sock.getOutputStream(),true);
input = new BufferedReader(
new InputStreamReader(sock.getInputStream()));
while(true){
listenStream();
}
} catch (Exception e) {
System.out.println("Run method fail. -> SocketManager.run()");
}finally{
try {
sock.close();
} catch (Exception e) {
}
}
}
}
Window.class
package com.client.core;
import java.awt.*;
import javax.swing.*;
public class Window extends JFrame{
private int screenWidth = 800;
private int screenHeight = 600;
private SocketManager network;
private JPanel window = new JPanel(new BorderLayout()),
center = new JPanel(new BorderLayout()),
right = new JPanel(new BorderLayout()),
display = new JPanel( new BorderLayout()),
chat = new JPanel(),
users = new JPanel(new BorderLayout());
private JTextArea chatBox = new JTextArea("Welcome to the chat!", 7,50),
listOfUsers = new JTextArea("None Online");
private JTextField chatWrite = new JTextField(),
userSearch = new JTextField(10),
username = new JTextField();
private JScrollPane userList = new JScrollPane(listOfUsers),
currentChat = new JScrollPane(chatBox);
private JMenuBar menu = new JMenuBar();
private JMenu file = new JMenu("File");
private JMenuItem exit = new JMenuItem("Exit"),
ipconnect = new JMenuItem("Connect to IP");
private JComponent[] login = new JComponent[]{new JLabel("Username:"), username};
public Window(){
//Initial Setup
super("NAMEHERE - Chat Client Alpha v0.0.1");
setResizable(true);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setSize(screenWidth,screenHeight);
//Panels
listOfUsers.setLineWrap(true);
listOfUsers.setEditable(false);
display.setBackground(Color.black);
chat.setLayout(new BoxLayout(chat, BoxLayout.Y_AXIS));
chat.setBackground(Color.blue);
users.setBackground(Color.green);
//TextFields
addChatArea();
//Menu bar
addMenuBar();
//Adding the main panels.
addPanels();
//Listeners
addListeners();
for(int x = 0; x < 1; x++){
login();
}
}
private void login(){
JOptionPane.showMessageDialog(null, login, "Log in", JOptionPane.PLAIN_MESSAGE);
}
private void addChatArea(){
chatBox.setEditable(false);
userList.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
currentChat.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
users.add(userList);
users.add(userSearch, BorderLayout.NORTH);
chat.add(currentChat);
chat.add(chatWrite);
chat.setBorder(BorderFactory.createEmptyBorder(1, 1, 1, 1));
}
private void addMenuBar(){
file.add(ipconnect);
file.add(exit);
menu.add(file);
}
private void addPanels(){
right.add(users);
center.add(display, BorderLayout.CENTER);
center.add(chat, BorderLayout.SOUTH);
window.add(center, BorderLayout.CENTER);
window.add(right, BorderLayout.EAST);
window.add(menu, BorderLayout.NORTH);
add(window);
}
private void addListeners(){
username.addActionListener(new ActLis(username, this));
chatWrite.addActionListener(new ActLis(chatWrite, this));
username.setActionCommand("setUsername");
chatWrite.setActionCommand("chatWriter");
ipconnect.addActionListener(new ActLis());
exit.addActionListener(new ActLis());
}
public void setNetwork(SocketManager n){
network = n;
}
public void updateChat(String s){
chatBox.setText(chatBox.getText() + "\n" + s);
}
}

Ok #Zexanima you have create a Socket class for socket manager. Something like this:
public class YouSocketClass {
static public Socket socket = null;
static public InputStream in = null;
static public OutputStream out = null;
public YouSocketClass() {
super();
}
public static final Socket getConnection(final String ip, final int port, final int timeout) {
try {
socket = new Socket(ip, port);
try {
socket.setSoTimeout(timeout);
} catch(SocketException se) {
log("Server Timeout");
}
in = socket.getInputStream();
out = socket.getOutputStream();
} catch(ConnectException e) {
log("Server name or server ip is failed. " + e.getMessage());
e.printStackTrace();
} catch(Exception e) {
log("ERROR Socket: " + e.getMessage() + " " + e.getCause());
e.printStackTrace();
}
return socket;
}
public static void closeConnection() {
try {
if(socket != null) {
if(in != null) {
if(out != null) {
socket.close();
in.close();
out.close();
}
}
}
} catch(Exception e2) {
e2.printStackTrace();
}
}
private static Object log(Object sms) {
System.out.println("Test Socket1.0: " + sms);
return sms;
}
}
I hope that serve. :)