Hi I am trying create a small client server or server client chat message application as an experiment and to gain some knowledge and experience in java socket. I have been having problem sending and receiving messages. I do get a connection and the Thread looks like it is running but it wouldn’t send or receive a message to each to other. I am not sure if the connection automatically closes once it connects but i know i am doing something wrong but i cant seem to find it. If you can help me that would be great. the code is below
Server:
public class ServerGUI extends JFrame implements KeyListener{
/**
*
*/
private static final long serialVersionUID = 1L;
/*private JButton sendButton = new JButton("send");
private JButton connectButton = new JButton("Connect");
private JButton disconnectButton = new JButton("Disconnect");*/
private JTextField textMessage = new JTextField();
private JLabel connectMessageLabel = new JLabel("Waiting for Client");
private JTextArea messageTextArea = new JTextArea();
private JPanel buttonPanel = new JPanel();
private JPanel messageLabelPanel = new JPanel();
private JPanel messageTextAreaPanel = new JPanel();
private JPanel content = new JPanel();
private static String thisName= "<Me> ";
private static String friendLabel= "<My Friend> ";
private static JFrame serverFrame = new JFrame();
private int port= 0;
private String clientMessage=null;
private String myMessage=null;
private ServerSocket listenSocket;
private Socket connection;
private InputStream inStream;
private DataInputStream inDataStream;
private OutputStream outStream;
private DataOutputStream outDataStream;
private Thread runChatServer;
//----------------------------------------------------------------------------------------------
//-------------------------serverGui------------------------------------------------------------
@SuppressWarnings("deprecation")
public ServerGUI(int port){
this.port = port;
messageLabelPanel.setLayout(new GridLayout(1, 1, 1, 1));
messageLabelPanel.add(connectMessageLabel);
buttonPanel.setLayout(new GridLayout(1, 1, 1, 1));
//buttonPanel.add(connectButton);
//buttonPanel.add(sendButton);
buttonPanel.add(textMessage);
textMessage.addKeyListener(this);
textMessage.setForeground(Color.BLACK);
messageTextAreaPanel.setLayout(new BorderLayout(1, 1));
messageTextAreaPanel.add(buttonPanel, BorderLayout.SOUTH);
messageTextAreaPanel.add(messageLabelPanel,BorderLayout.NORTH);
messageTextAreaPanel.add(new JScrollPane(messageTextArea),BorderLayout.CENTER);
messageTextArea.setDisabledTextColor(Color.BLACK);
messageTextArea.enable(false);
content.setLayout(new GridLayout(1, 1, 1, 1));
content.add(messageTextAreaPanel);
content.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
serverFrame.setContentPane(content);
serverFrame.pack();
serverFrame.setSize(450,550);
serverFrame.setLocationRelativeTo(null);
serverFrame.setVisible(true);
serverFrame.setTitle("Chat Server");
serverFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
startServer();
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------keyPressed------------------------------------------------------------
public void startServer(){
System.out.println("startServer");
try{
listenSocket = new ServerSocket(port);
System.out.println("Waiting for client");
connection = listenSocket.accept();
System.out.println("Client Found");
connectMessageLabel.setText("Client Found");
runChatServer = new Thread(serverListeningAndChatting);
runChatServer.start();
}
catch (Exception ex){
System.out.println("No Connection Found");
connectMessageLabel.setText("No Connection Found");
}
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------listening------------------------------------------------------------
public void listening(){
System.out.println("listening");
try{
inStream = connection.getInputStream();
inDataStream = new DataInputStream(inStream);
clientMessage = inDataStream.readUTF();
if (clientMessage!= null){
messageTextArea.append(clientMessage + "\n");
clientMessage = null;
}
}catch(Exception ex){System.out.println(ex);}
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------sendMessage------------------------------------------------------------
public void sendMessage(){
System.out.println("sendMessage");
try{
outStream = connection.getOutputStream();
outDataStream = new DataOutputStream(outStream);
if (myMessage!=null){
outDataStream.writeUTF(myMessage);
myMessage=null;
}
}catch(Exception ex){System.out.println("Message Failed");}
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------keyPressed------------------------------------------------------------
public void keyPressed(KeyEvent e) {
if(e.getKeyChar() == KeyEvent.VK_ENTER){
myMessage = friendLabel+ textMessage.getText();
messageTextArea.append(thisName+textMessage.getText() +"\n");
textMessage.setText("");
}
}
public void keyReleased(KeyEvent e) {}
public void keyTyped(KeyEvent e) {}
//-----------------------------------------------------------------------------------------------------
//-------------------------------main------------------------------------------------------------
public static void main (String args[]){
new ServerGUI(8901);
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------run------------------------------------------------------------
public Runnable serverListeningAndChatting = new Runnable(){
public void run() {
while (true){
System.out.println("Running");
listening();
sendMessage();
}
}
};
}
Client:
public class ClientGUI extends JFrame implements KeyListener{
/**
*
*/
private static final long serialVersionUID = 1L;
private JTextField textMessage = new JTextField();
private JLabel connectMessageLabel = new JLabel("Connection failed or no Server is available");
private JTextArea messageTextArea = new JTextArea();
private JPanel buttonPanel = new JPanel();
private JPanel messageLabelPanel = new JPanel();
private JPanel messageTextAreaPanel = new JPanel();
private JPanel content = new JPanel();
private static String thisName= "<Me> ";
private static String friendLabel= "<My Friend> ";
private static JFrame clientFrame = new JFrame();
private int port =0;
private String remoteMachine =null;
private String clientMessage=null;
private String myMessage=null;
private Socket connection;
private InputStream inStream;
private DataInputStream inDataStream;
private OutputStream outStream;
private DataOutputStream outDataStream;
private Thread runChatClient;
//-----------------------------------------------------------------------------------------------------
//-------------------------------ClientGUI------------------------------------------------------------
@SuppressWarnings("deprecation")
public ClientGUI(String remoteMachine, int port){
this.port= port;
this.remoteMachine = remoteMachine;
messageLabelPanel.setLayout(new GridLayout(1, 1, 1, 1));
messageLabelPanel.add(connectMessageLabel);
buttonPanel.setLayout(new GridLayout(1, 1, 1, 1));
//buttonPanel.add(connectButton);
//buttonPanel.add(sendButton);
buttonPanel.add(textMessage);
textMessage.addKeyListener(this);
textMessage.setForeground(Color.BLACK);
messageTextAreaPanel.setLayout(new BorderLayout(1, 1));
messageTextAreaPanel.add(buttonPanel, BorderLayout.SOUTH);
messageTextAreaPanel.add(messageLabelPanel,BorderLayout.NORTH);
messageTextAreaPanel.add(new JScrollPane(messageTextArea),BorderLayout.CENTER);
messageTextArea.setDisabledTextColor(Color.BLACK);
messageTextArea.enable(false);
content.setLayout(new GridLayout(1, 1, 1, 1));
content.add(messageTextAreaPanel);
content.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
clientFrame.setContentPane(content);
clientFrame.pack();
clientFrame.setSize(450,550);
clientFrame.setLocationRelativeTo(null);
clientFrame.setVisible(true);
clientFrame.setTitle("Chat Client");
clientFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
startClient();
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------startClient------------------------------------------------------------
public void startClient(){
System.out.println("startClient");
try{
System.out.println("Connecting to Server");
connection = new Socket(remoteMachine, port);
System.out.println("Server Found");
connectMessageLabel.setText("Server Found");
runChatClient = new Thread(clientListeningAndChatting);
runChatClient.start();
}
catch (Exception ex){
System.out.println("No Connection Found");
connectMessageLabel.setText("No Connection Found");
}
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------keyPressed------------------------------------------------------------
public void keyPressed(KeyEvent e) {
if(e.getKeyChar() == KeyEvent.VK_ENTER){
myMessage = friendLabel+ textMessage.getText();
messageTextArea.append(thisName+textMessage.getText() +"\n");
textMessage.setText("");
}
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------listening------------------------------------------------------------
public void listening(){
System.out.println("listening");
try{
inStream = connection.getInputStream();
inDataStream = new DataInputStream(inStream);
clientMessage = inDataStream.readUTF();
if (clientMessage!= null){
messageTextArea.append(clientMessage + "\n");
clientMessage = null;
}
}catch(Exception ex){System.out.println("Disconnected");}
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------sendMessage------------------------------------------------------------
public void sendMessage(){
System.out.println("sendMessage");
try{
outStream = connection.getOutputStream();
outDataStream = new DataOutputStream(outStream);
if (myMessage!=null){
outDataStream.writeUTF(myMessage);
myMessage=null;
}
}catch(Exception ex){System.out.println("Message Failed");}
}
public void keyReleased(KeyEvent e) {}
public void keyTyped(KeyEvent e) {}
//-----------------------------------------------------------------------------------------------------
//-------------------------------main------------------------------------------------------------
public static void main (String args[]){
new ClientGUI(null, 8901);
}
//-----------------------------------------------------------------------------------------------------
//-------------------------------run------------------------------------------------------------
public Runnable clientListeningAndChatting = new Runnable(){
public void run() {
System.out.println("Running");
while (true){
listening();
sendMessage();
}
}
};
}
The statement
is a blocking call is is blocking the
EDT. This and any other network access calls should be handled by a SwingWorker. As Swing is single threaded, no events can be processed so no messages can be exchanged between the client & server.Use
SwingWorkeroverThread—it takes care of GUI interaction tasks.