Shrink code in the ConnectionHandlers

Fixes issue #37

client/src/main/java/ch/zhaw/pm2/multichat/client/ChatWindowController.java

@@ -1,12 +1,12 @@
 package ch.zhaw.pm2.multichat.client;
 
-import ch.zhaw.pm2.multichat.client.ClientConnectionHandler.State;
+import ch.zhaw.pm2.multichat.protocol.ConnectionHandler.State;
 import ch.zhaw.pm2.multichat.protocol.ChatProtocolException;
+import ch.zhaw.pm2.multichat.protocol.ConnectionHandler;
 import ch.zhaw.pm2.multichat.protocol.NetworkHandler;
 import javafx.application.Platform;
 import javafx.beans.value.ChangeListener;
 import javafx.beans.value.ObservableValue;
-import javafx.collections.ListChangeListener;
 import javafx.event.EventHandler;
 import javafx.fxml.FXML;
 import javafx.scene.control.Button;
@@ -16,10 +16,8 @@ import javafx.scene.layout.Pane;
 import javafx.stage.WindowEvent;
 
 import java.io.IOException;
-import java.util.regex.Matcher;
-import java.util.regex.Pattern;
 
-import static ch.zhaw.pm2.multichat.client.ClientConnectionHandler.State.*;
+import static ch.zhaw.pm2.multichat.protocol.ConnectionHandler.State.*;
 
 public class ChatWindowController {
     private ClientConnectionHandler connectionHandler;
@@ -42,23 +40,24 @@ public class ChatWindowController {
     public void initialize() {
         serverAddressField.setText(NetworkHandler.DEFAULT_ADDRESS.getCanonicalHostName());
         serverPortField.setText(String.valueOf(NetworkHandler.DEFAULT_PORT));
-        this.messages = new ClientMessageList();
-
-        messages.getChangedProperty().addListener(new ChangeListener<Boolean>() {
-            @Override
-            public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
-                setMessageField(messages.getMessages());
     }
-        });
+
+    public void setMessages(ClientMessageList messages) {
+        this.messages = messages;
+        messageListener();
+    }
+
+    public void setConnectionHandler(ClientConnectionHandler connectionHandler){
+        this.connectionHandler = connectionHandler;
     }
 
     private void applicationClose() {
-        connectionHandler.setState(DISCONNECTED);
+        disconnect();
     }
 
     @FXML
     private void toggleConnection () {
-        if (connectionHandler == null || connectionHandler.getStateObjectProperty().get() != CONNECTED) {
+        if (connectionHandler == null || connectionHandler.getStateProperty().get() != CONNECTED) {
             connect();
         } else {
             disconnect();
@@ -71,19 +70,19 @@ public class ChatWindowController {
             startConnectionHandler();
             connectionHandler.connect();
         } catch(ChatProtocolException | IOException e) {
-            messages.addMessage(null,null, e.getMessage(), Message.MessageType.ERROR);
+            addError(e.getMessage());
         }
     }
 
     private void disconnect() {
         if (connectionHandler == null) {
-            messages.addMessage(null,null,"No connection handler", Message.MessageType.ERROR);
+            addError("No connection handler");
             return;
         }
         try {
             connectionHandler.disconnect();
         } catch (ChatProtocolException e) {
-            messages.addMessage(null,null, e.getMessage(), Message.MessageType.ERROR);
+            addError(e.getMessage());
         }
     }
 
@@ -92,43 +91,37 @@ public class ChatWindowController {
         String messageString = messageField.getText().strip();
         try {
             if (connectionHandler == null) {
-                messages.addMessage(null,null,"No connection handler", Message.MessageType.ERROR);
+                addError("No connection handler");
             } else if (!connectionHandler.message(messageString)) {
-                messages.addMessage(null,null,"Not a valid message format.", Message.MessageType.ERROR);
+                addError("Not a valid message format.");
             } else {
                 messageField.clear();
             }
         } catch (ChatProtocolException e) {
-            messages.addMessage(null,null, e.getMessage(), Message.MessageType.ERROR);
+            addError(e.getMessage());
         }
     }
 
-    //TODO: TEST
     @FXML
     private void applyFilter( ) {
-        messages.getFilteredMessages(filterValue.getText().strip());
+    	this.redrawMessageList();
     }
 
     private void startConnectionHandler() throws IOException {
         String userName = userNameField.getText();
+        if(!userName.contains(" ")) {
             String serverAddress = serverAddressField.getText();
             int serverPort = Integer.parseInt(serverPortField.getText());
-        connectionHandler = new ClientConnectionHandler(messages,serverAddress,serverPort,userName);
+            connectionHandler.initialize(serverAddress, serverPort, userName);
             new Thread(connectionHandler).start();
 
-        //register changelistener
+            //register Listener
-        startChangeListener();
+            startListener();
 
             // register window close handler
             rootPane.getScene().getWindow().addEventHandler(WindowEvent.WINDOW_CLOSE_REQUEST, windowCloseHandler);
-    }
+        } else {
-
+            addError("It is not allowed to have spaces in username!");
-    private void terminateConnectionHandler() {
-        // unregister window close handler
-        rootPane.getScene().getWindow().removeEventHandler(WindowEvent.WINDOW_CLOSE_REQUEST, windowCloseHandler);
-        if (connectionHandler != null) {
-            connectionHandler.stopReceiving();
-            connectionHandler = null;
         }
     }
 
@@ -140,54 +133,11 @@ public class ChatWindowController {
                 connectButton.setText((newState == CONNECTED || newState == CONFIRM_DISCONNECT) ? "Disconnect" : "Connect");
             }
         });
-        if (newState == DISCONNECTED) {
+        if(newState == DISCONNECTED){
-            terminateConnectionHandler();
+            connectionHandler.stopReceiving();
         }
     }
 
-    private void startChangeListener() {
-        //Listener for State
-        connectionHandler.getStateObjectProperty().addListener(new ChangeListener<State>() {
-            @Override
-            public void changed(ObservableValue<? extends State> observable, State oldValue, State newValue) {
-                stateChanged(newValue);
-            }
-        });
-
-        //Listener for Username
-        connectionHandler.getUserNameProperty().addListener(new ChangeListener<String>() {
-            @Override
-            public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
-                setUserName(newValue);
-            }
-        });
-
-        //Listener for Address
-        connectionHandler.getServerAddressProperty().addListener(new ChangeListener<String>() {
-            @Override
-            public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
-                setServerAddress(newValue);
-            }
-        });
-
-        //Listener for Port
-        connectionHandler.getServerPortProperty().addListener(new ChangeListener<Number>() {
-            @Override
-            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
-                setServerPort(newValue.intValue());
-            }
-        });
-    }
-
-    public void setMessageField(String message) {
-        Platform.runLater(new Runnable() {
-            @Override
-            public void run() {
-                messageField.setText(message);
-            }
-        });
-    }
-
     public void setUserName(String userName) {
         Platform.runLater(new Runnable() {
             @Override
@@ -215,7 +165,10 @@ public class ChatWindowController {
         });
     }
 
-    //TODO: MAKE ChangeListener
+    public void addError(String message) {
+        messages.addMessage(new Message(Message.MessageType.ERROR, null, null, message));
+    }
+
     private void redrawMessageList() {
         this.messageArea.clear();
         Platform.runLater(() -> this.messageArea.setText(messages.getFilteredMessages(filterValue.getText().strip())));
@@ -228,4 +181,43 @@ public class ChatWindowController {
 
     }
 
+    public void startListener() {
+        connectionHandler.getStateProperty().addListener(new ChangeListener<State>() {
+            @Override
+            public void changed(ObservableValue<? extends State> observable, State oldValue, State newValue) {
+                stateChanged(newValue);
+            }
+        });
+
+        connectionHandler.getUserNameProperty().addListener(new ChangeListener<String>() {
+            @Override
+            public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
+                setUserName(newValue);
+            }
+        });
+
+        connectionHandler.getServerAddressProperty().addListener(new ChangeListener<String>() {
+            @Override
+            public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue) {
+                setServerAddress(newValue);
+            }
+        });
+
+        connectionHandler.getServerPortProperty().addListener(new ChangeListener<Number>() {
+            @Override
+            public void changed(ObservableValue<? extends Number> observable, Number oldValue, Number newValue) {
+                setServerPort(newValue.intValue());
+            }
+        });
+    }
+
+    private void messageListener() {
+        messages.getChangedProperty().addListener(new ChangeListener<Boolean>() {
+            @Override
+            public void changed(ObservableValue<? extends Boolean> observable, Boolean oldValue, Boolean newValue) {
+                redrawMessageList();
+            }
+        });
+    }
+
 }

client/src/main/java/ch/zhaw/pm2/multichat/client/ClientConnectionHandler.java

@@ -1,8 +1,8 @@
 package ch.zhaw.pm2.multichat.client;
 
 import ch.zhaw.pm2.multichat.protocol.ChatProtocolException;
+import ch.zhaw.pm2.multichat.protocol.ConnectionHandler;
 import ch.zhaw.pm2.multichat.protocol.NetworkHandler;
-import javafx.beans.property.ObjectProperty;
 import javafx.beans.property.SimpleIntegerProperty;
 import javafx.beans.property.SimpleObjectProperty;
 import javafx.beans.property.SimpleStringProperty;
@@ -13,73 +13,59 @@ import java.net.SocketException;
 import java.util.Scanner;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import static ch.zhaw.pm2.multichat.protocol.ConnectionHandler.State.*;
 
-import static ch.zhaw.pm2.multichat.client.ClientConnectionHandler.State.*;
+public class ClientConnectionHandler extends ConnectionHandler implements Runnable {
-import static ch.zhaw.pm2.multichat.client.Message.MessageType.*;
 
-public class ClientConnectionHandler implements Runnable {
+    private final Pattern messagePattern = Pattern.compile( "^(?:@(\\S*))?\\s*(.*)$" );
-    private NetworkHandler.NetworkConnection<String> connection;
-
-    // Data types used for the Chat Protocol
-    private static final String DATA_TYPE_CONNECT = "CONNECT";
-    private static final String DATA_TYPE_CONFIRM = "CONFIRM";
-    private static final String DATA_TYPE_DISCONNECT = "DISCONNECT";
-    private static final String DATA_TYPE_MESSAGE = "MESSAGE";
-    private static final String DATA_TYPE_ERROR = "ERROR";
-
-    public static final String USER_NONE = "";
-    public static final String USER_ALL = "*";
 
     private SimpleStringProperty userName;
-    private SimpleIntegerProperty serverPort;
+    private SimpleObjectProperty<State> state;
+    private ClientMessageList messages;
     private SimpleStringProperty serverAddress;
-    private ObjectProperty<State> stateObjectProperty;
+    private SimpleIntegerProperty serverPort;
-    private ClientMessageList messageList;
-    private final Pattern messagePattern = Pattern.compile( "^(?:@(\\w*))?\\s*(.*)$" );
 
-    enum State {
+    public ClientConnectionHandler(ClientMessageList messages)  {
-        NEW, CONFIRM_CONNECT, CONNECTED, CONFIRM_DISCONNECT, DISCONNECTED;
+        super();
+        this.messages = messages;
+        state = new SimpleObjectProperty<>(State.NEW);
+        serverAddress = new SimpleStringProperty(NetworkHandler.DEFAULT_ADDRESS.getCanonicalHostName());
+        serverPort = new SimpleIntegerProperty(NetworkHandler.DEFAULT_PORT);
+        this.userName = new SimpleStringProperty(null);
     }
 
-    public ClientConnectionHandler(ClientMessageList messageList,String serverAddress,int serverPort,String userName) throws IOException {
+    public void initialize(String serverAddress, int serverPort, String userName) throws IOException {
-        this.stateObjectProperty = new SimpleObjectProperty<>(NEW);
+        state.set(NEW);
+        this.serverAddress.set(serverAddress);
+        this.serverPort.set(serverPort);
+        setConnection(NetworkHandler.openConnection(serverAddress, serverPort));
         this.userName = new SimpleStringProperty((userName == null || userName.isBlank())? USER_NONE : userName);
-        this.serverPort = new SimpleIntegerProperty();
-        this.serverAddress = new SimpleStringProperty();
-        this.messageList = messageList;
-        this.connection = NetworkHandler.openConnection(serverAddress,serverPort);
     }
 
-    public ObjectProperty<State> getStateObjectProperty() {
+    public SimpleStringProperty getServerAddressProperty() { return serverAddress; }
-        return stateObjectProperty;
+
+    public SimpleIntegerProperty getServerPortProperty() { return serverPort; }
+
+    public SimpleObjectProperty<State> getStateProperty() {
+        return this.state;
     }
 
-    public SimpleStringProperty getUserNameProperty() {
+    public SimpleStringProperty getUserNameProperty() { return userName; }
-        return userName;
-    }
-
-    public SimpleStringProperty getServerAddressProperty() {
-        return serverAddress;
-    }
-
-    public SimpleIntegerProperty getServerPortProperty() {
-        return serverPort;
-    }
 
     public void setState (State newState) {
-        this.stateObjectProperty.set(newState);
+        state.set(newState);
     }
 
     public void run () {
         startReceiving();
     }
 
-    public void startReceiving() {
+    private void startReceiving() {
         System.out.println("Starting Connection Handler");
         try {
             System.out.println("Start receiving data...");
-            while (connection.isAvailable()) {
+            while (getConnection().isAvailable()) {
-                String data = connection.receive();
+                String data = getConnection().receive();
                 processData(data);
             }
             System.out.println("Stopped recieving data");
@@ -103,7 +89,7 @@ public class ClientConnectionHandler implements Runnable {
         System.out.println("Closing Connection Handler to Server");
         try {
             System.out.println("Stop receiving data...");
-            connection.close();
+            getConnection().close();
             System.out.println("Stopped receiving data.");
         } catch (IOException e) {
             System.err.println("Failed to close connection." + e.getMessage());
@@ -111,113 +97,90 @@ public class ClientConnectionHandler implements Runnable {
         System.out.println("Closed Connection Handler to Server");
     }
 
-
     private void processData(String data) {
         try {
-            // parse data content
             Scanner scanner = new Scanner(data);
-            String sender = null;
+            StringBuilder sender = new StringBuilder();
-            String reciever = null;
+            StringBuilder reciever = new StringBuilder();
-            String type = null;
+            StringBuilder type = new StringBuilder();
-            String payload = null;
+            StringBuilder payload = new StringBuilder();
-            if (scanner.hasNextLine()) {
+            super.processData(scanner,sender,reciever,type,payload);
-                sender = scanner.nextLine();
+
-            } else {
-                throw new ChatProtocolException("No Sender found");
-            }
-            if (scanner.hasNextLine()) {
-                reciever = scanner.nextLine();
-            } else {
-                throw new ChatProtocolException("No Reciever found");
-            }
-            if (scanner.hasNextLine()) {
-                type = scanner.nextLine();
-            } else {
-                throw new ChatProtocolException("No Type found");
-            }
-            if (scanner.hasNextLine()) {
-                payload = scanner.nextLine();
-            }
             // dispatch operation based on type parameter
-            if (type.equals(DATA_TYPE_CONNECT)) {
+            if (type.toString().equals(getDataTypeConnect())) {
                 System.err.println("Illegal connect request from server");
-            } else if (type.equals(DATA_TYPE_CONFIRM)) {
+            } else if (type.toString().equals(getDataTypeConfirm())) {
-                if (stateObjectProperty.get() == CONFIRM_CONNECT) {
+                caseConfirm(sender.toString(), reciever.toString(), payload.toString());
-                    this.userName.set(reciever);
+            } else if (type.toString().equals(getDataTypeDisconnect())) {
-                    this.serverAddress.set(connection.getRemoteHost());
+                caseDisconnect(sender.toString(),reciever.toString(),payload.toString());
-                    this.serverPort.set(connection.getRemotePort());
+            } else if (type.toString().equals(getDataTypeMessage())) {
-                    messageList.addMessage(sender,reciever,payload,INFO);
+                caseMessage(sender.toString(),reciever.toString(),payload.toString());
-                    System.out.println("CONFIRM: " + payload);
+            } else if (type.toString().equals(getDataTypeError())) {
-                    this.setState(CONNECTED);
+                caseError(sender.toString(), reciever.toString(), payload.toString());
-                } else if (stateObjectProperty.get() == CONFIRM_DISCONNECT) {
-                    messageList.addMessage(sender,reciever,payload,INFO);
-                    System.out.println("CONFIRM: " + payload);
-                    this.setState(DISCONNECTED);
-                } else {
-                    System.err.println("Got unexpected confirm message: " + payload);
-                }
-            } else if (type.equals(DATA_TYPE_DISCONNECT)) {
-                if (stateObjectProperty.get() == DISCONNECTED) {
-                    System.out.println("DISCONNECT: Already in disconnected: " + payload);
-                    return;
-                }
-                messageList.addMessage(sender,reciever,payload,INFO);
-                System.out.println("DISCONNECT: " + payload);
-                this.setState(DISCONNECTED);
-            } else if (type.equals(DATA_TYPE_MESSAGE)) {
-                if (stateObjectProperty.get() != CONNECTED) {
-                    System.out.println("MESSAGE: Illegal state " + stateObjectProperty.get() + " for message: " + payload);
-                    return;
-                }
-                messageList.addMessage(sender,reciever,payload,MESSAGE);
-                System.out.println("MESSAGE: From " + sender + " to " + reciever + ": "+  payload);
-            } else if (type.equals(DATA_TYPE_ERROR)) {
-                messageList.addMessage(sender,reciever,payload,ERROR);
-                System.out.println("ERROR: " + payload);
             } else {
                 System.out.println("Unknown data type received: " + type);
             }
         } catch (ChatProtocolException e) {
             System.err.println("Error while processing data: " + e.getMessage());
-            sendData(USER_NONE, userName.get(), DATA_TYPE_ERROR, e.getMessage());
+            sendData(USER_NONE, userName.get(), getDataTypeError(), e.getMessage());
         }
     }
 
-    public void sendData(String sender, String receiver, String type, String payload) {
+    private void caseConfirm(String sender, String reciever, String payload) {
-        if (connection.isAvailable()) {
+        if (state.get() == CONFIRM_CONNECT) {
-            new StringBuilder();
+            this.userName.set(reciever);
-            String data = new StringBuilder()
+            this.serverPort.set(getConnection().getRemotePort());
-                .append(sender+"\n")
+            this.serverAddress.set(getConnection().getRemoteHost());
-                .append(receiver+"\n")
+            messages.addMessage(new Message(Message.MessageType.INFO,sender,reciever,payload));
-                .append(type+"\n")
+            System.out.println("CONFIRM: " + payload);
-                .append(payload+"\n")
+            this.setState(CONNECTED);
-                .toString();
+        } else if (state.get() == CONFIRM_DISCONNECT) {
-            try {
+            messages.addMessage(new Message(Message.MessageType.INFO,sender,reciever,payload));
-                connection.send(data);
+            System.out.println("CONFIRM: " + payload);
-            } catch (SocketException e) {
+            this.setState(DISCONNECTED);
-                System.err.println("Connection closed: " + e.getMessage());
+        } else {
-            } catch (EOFException e) {
+            System.err.println("Got unexpected confirm message: " + payload);
-                System.out.println("Connection terminated by remote");
-            } catch(IOException e) {
-                System.err.println("Communication error: " + e.getMessage());
         }
     }
+
+    private void caseDisconnect(String sender, String reciever, String payload) {
+        if (state.get() == DISCONNECTED) {
+            System.out.println("DISCONNECT: Already in disconnected: " + payload);
+            return;
+        }
+        messages.addMessage(new Message(Message.MessageType.INFO,sender,reciever,payload));
+        System.out.println("DISCONNECT: " + payload);
+        this.setState(DISCONNECTED);
+    }
+
+    private void caseMessage(String sender, String reciever, String payload) {
+        if (state.get() != CONNECTED) {
+            System.out.println("MESSAGE: Illegal state " + state + " for message: " + payload);
+            return;
+        }
+        messages.addMessage(new Message(Message.MessageType.MESSAGE,sender,reciever,payload));
+        System.out.println("MESSAGE: From " + sender + " to " + reciever + ": "+  payload);
+    }
+
+    private void caseError(String sender, String reciever, String payload) {
+        messages.addMessage(new Message(Message.MessageType.ERROR,sender,reciever,payload));
+        System.out.println("ERROR: " + payload);
     }
 
     public void connect() throws ChatProtocolException {
-        if (stateObjectProperty.get() != NEW) throw new ChatProtocolException("Illegal state for connect: " + stateObjectProperty.get());
+        if (state.get() != NEW) throw new ChatProtocolException("Illegal state for connect: " + state);
-        this.sendData(userName.get(), USER_NONE, DATA_TYPE_CONNECT,null);
+        this.sendData(userName.get(), USER_NONE, getDataTypeConnect(),null);
         this.setState(CONFIRM_CONNECT);
     }
 
     public void disconnect() throws ChatProtocolException {
-        if (stateObjectProperty.get() != NEW && stateObjectProperty.get() != CONNECTED) throw new ChatProtocolException("Illegal state for disconnect: " + stateObjectProperty.get());
+        if (state.get() != NEW && state.get() != CONNECTED) throw new ChatProtocolException("Illegal state for disconnect: " + state);
-        this.sendData(userName.get(), USER_NONE, DATA_TYPE_DISCONNECT,null);
+        this.sendData(userName.get(), USER_NONE, getDataTypeDisconnect(),null);
         this.setState(CONFIRM_DISCONNECT);
     }
 
     public boolean message(String messageString) throws ChatProtocolException {
-        if (stateObjectProperty.get() != CONNECTED) throw new ChatProtocolException("Illegal state for message: " + stateObjectProperty.get());
+        if (state.get() != CONNECTED) throw new ChatProtocolException("Illegal state for message: " + state);
 
         Matcher matcher = messagePattern.matcher(messageString);
         if (matcher.find()) {
@@ -227,11 +190,10 @@ public class ClientConnectionHandler implements Runnable {
                 return false;
             }
             if (receiver == null || receiver.isBlank()) receiver = ClientConnectionHandler.USER_ALL;
-            this.sendData(userName.get(), receiver, DATA_TYPE_MESSAGE,message);
+            this.sendData(userName.get(), receiver, getDataTypeMessage(),message);
             return true;
         } else {
             return false;
         }
     }
-
 }

client/src/main/java/ch/zhaw/pm2/multichat/client/ClientMessageList.java

@@ -1,33 +1,16 @@
 package ch.zhaw.pm2.multichat.client;
 
 import javafx.beans.property.SimpleBooleanProperty;
-import javafx.beans.property.SimpleListProperty;
-import javafx.collections.FXCollections;
-import javafx.collections.ObservableList;
 
 import java.util.ArrayList;
 import java.util.List;
 
-import static ch.zhaw.pm2.multichat.client.ClientConnectionHandler.USER_NONE;
-
 public class ClientMessageList {
-    private List<Message> messages;
+    private List<Message> messages = new ArrayList<>();
-    private SimpleBooleanProperty changed;
+    private SimpleBooleanProperty changed = new SimpleBooleanProperty(false);
 
-    public ClientMessageList() {
+    public void addMessage(Message message) {
-        messages = new ArrayList<>();
+	    messages.add(message);
-        changed = new SimpleBooleanProperty(true);
-    }
-
-    public SimpleBooleanProperty getChangedProperty() {
-        return changed;
-    }
-
-    public void addMessage(String sender, String receiver, String message, Message.MessageType type) {
-        if(sender == null) {
-            sender = USER_NONE;
-        }
-        messages.add(new Message(type, sender, receiver, message));
 	    changed.set(!changed.get());
     }
 
@@ -48,21 +31,11 @@ public class ClientMessageList {
         return result.toString();
 	}
 
-	public String getMessages() {
+    public void clear() {
-        StringBuilder result = new StringBuilder();
+        messages = new ArrayList<>();
-        for(Message message : messages) {
+        changed.set(!changed.get());
-            switch (message.getType()) {
-                case MESSAGE -> result.append(String.format("[%s -> %s] %s\n", message.getSender(), message.getReceiver(), message.getText()));
-                case ERROR -> result.append(String.format("[ERROR] %s\n", message.getText()));
-                case INFO -> result.append(String.format("[INFO] %s\n", message.getText()));
-                default -> result.append(String.format("[ERROR] %s\n", "Unexpected message type: " + message.getType()));
-            }
-        }
-        return result.toString();
     }
 
-    public void clear() {
+    public SimpleBooleanProperty getChangedProperty() { return changed; }
-        messages = new SimpleListProperty<>();
-    }
 
 }

client/src/main/java/ch/zhaw/pm2/multichat/client/ClientUI.java

@@ -8,6 +8,7 @@ import javafx.stage.Stage;
 
 public class ClientUI extends Application {
     private ClientMessageList clientMessageList = new ClientMessageList();
+    private ClientConnectionHandler connectionHandler = new ClientConnectionHandler(clientMessageList);
 
     @Override
     public void start(Stage primaryStage) {
@@ -17,9 +18,12 @@ public class ClientUI extends Application {
     private void chatWindow(Stage primaryStage) {
         try {
             FXMLLoader loader = new FXMLLoader(getClass().getResource("ChatWindow.fxml"));
-
             Pane rootPane = loader.load();
 
+            ChatWindowController chatWindowController = loader.getController();
+            chatWindowController.setMessages(clientMessageList);
+            chatWindowController.setConnectionHandler(connectionHandler);
+
             // fill in scene and stage setup
             Scene scene = new Scene(rootPane);
             //scene.getStylesheets().add(getClass().getResource("application.css").toExternalForm());

protocol/src/main/java/ch/zhaw/pm2/multichat/protocol/ConnectionHandler.java

@@ -0,0 +1,95 @@
+package ch.zhaw.pm2.multichat.protocol;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.net.SocketException;
+import java.util.Scanner;
+
+public abstract class ConnectionHandler {
+    private NetworkHandler.NetworkConnection<String> connection;
+
+    // Data types used for the Chat Protocol
+    private static final String DATA_TYPE_CONNECT = "CONNECT";
+    private static final String DATA_TYPE_CONFIRM = "CONFIRM";
+    private static final String DATA_TYPE_DISCONNECT = "DISCONNECT";
+    private static final String DATA_TYPE_MESSAGE = "MESSAGE";
+    private static final String DATA_TYPE_ERROR = "ERROR";
+
+    public static final String USER_NONE = "";
+    public static final String USER_ALL = "*";
+
+    public enum State {
+        NEW, CONFIRM_CONNECT, CONNECTED, CONFIRM_DISCONNECT, DISCONNECTED, ERROR;
+    }
+
+    public static String getDataTypeConnect() {
+        return DATA_TYPE_CONNECT;
+    }
+
+    public static String getDataTypeConfirm() {
+        return DATA_TYPE_CONFIRM;
+    }
+
+    public static String getDataTypeDisconnect() {
+        return DATA_TYPE_DISCONNECT;
+    }
+
+    public static String getDataTypeMessage() {
+        return DATA_TYPE_MESSAGE;
+    }
+
+    public static String getDataTypeError() {
+        return DATA_TYPE_ERROR;
+    }
+
+    public NetworkHandler.NetworkConnection<String> getConnection() {
+        return connection;
+    }
+
+    protected void setConnection(NetworkHandler.NetworkConnection<String> connection) {
+        this.connection = connection;
+    }
+
+    protected void processData(Scanner scanner, StringBuilder sender, StringBuilder reciever, StringBuilder type, StringBuilder payload) throws ChatProtocolException {
+        // parse data content
+        if (scanner.hasNextLine()) {
+            sender.append(scanner.nextLine());
+        } else {
+            throw new ChatProtocolException("No Sender found");
+        }
+        if (scanner.hasNextLine()) {
+            reciever.append(scanner.nextLine());
+        } else {
+            throw new ChatProtocolException("No Reciever found");
+        }
+        if (scanner.hasNextLine()) {
+            type.append(scanner.nextLine());
+        } else {
+            throw new ChatProtocolException("No Type found");
+        }
+        if (scanner.hasNextLine()) {
+            payload.append(scanner.nextLine());
+        }
+    }
+
+    protected void sendData(String sender, String receiver, String type, String payload) {
+        if (connection.isAvailable()) {
+            new StringBuilder();
+            String data = new StringBuilder()
+                    .append(sender+"\n")
+                    .append(receiver+"\n")
+                    .append(type+"\n")
+                    .append(payload+"\n")
+                    .toString();
+            try {
+                getConnection().send(data);
+            } catch (SocketException e) {
+                System.err.println("Connection closed: " + e.getMessage());
+            } catch (EOFException e) {
+                System.out.println("Connection terminated by remote");
+            } catch(IOException e) {
+                System.err.println("Communication error: " + e.getMessage());
+            }
+        }
+    }
+}

server/src/main/java/ch/zhaw/pm2/multichat/server/Server.java

@@ -1,11 +1,14 @@
 package ch.zhaw.pm2.multichat.server;
 
+import ch.zhaw.pm2.multichat.protocol.ConnectionHandler;
 import ch.zhaw.pm2.multichat.protocol.NetworkHandler;
 
 import java.io.IOException;
 import java.net.SocketException;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.ReentrantLock;
 
 
 public class Server {
@@ -62,23 +65,40 @@ public class Server {
     }
 
     private void start() {
+        ReentrantLock mutex = new ReentrantLock();
+        Condition nameComplete = mutex.newCondition();
         System.out.println("Server started.");
         try {
             while (true) {
                  NetworkHandler.NetworkConnection<String> connection = networkServer.waitForConnection();
-                 ServerConnectionHandler connectionHandler = new ServerConnectionHandler(connection, connections);
+                 ServerConnectionHandler connectionHandler = new ServerConnectionHandler(connection, connections, mutex, nameComplete);
                  new Thread(connectionHandler).start();
+                 mutex.lock();
+                 try {
+                     nameComplete.await();
+                     if(connectionHandler.getState() == ConnectionHandler.State.ERROR) {
+                         System.out.println(String.format("Connecting failed for new Client with IP:Port <%s:%d>.\nReason: Name already taken.",
+                                 connection.getRemoteHost(),
+                                 connection.getRemotePort()));
+                     }
+                     else {
                          System.out.println(String.format("Connected new Client %s with IP:Port <%s:%d>",
                                  connectionHandler.getUserName(),
                                  connection.getRemoteHost(),
-                     connection.getRemotePort()
+                                 connection.getRemotePort()));
-                 ));
+                     }
+                 }
+                finally {
+                     mutex.unlock();
+                 }
             }
         } catch(SocketException e) {
             System.out.println("Server connection terminated");
         }
         catch (IOException e) {
             System.err.println("Communication error " + e);
+        } catch (InterruptedException e) {
+            throw new RuntimeException(e);
         }
         // close server
         System.out.println("Server Stopped.");

server/src/main/java/ch/zhaw/pm2/multichat/server/ServerConnectionHandler.java

@@ -1,34 +1,30 @@
 package ch.zhaw.pm2.multichat.server;
 
 import ch.zhaw.pm2.multichat.protocol.ChatProtocolException;
+import ch.zhaw.pm2.multichat.protocol.ConnectionHandler;
+import static ch.zhaw.pm2.multichat.protocol.ConnectionHandler.State.*;
 import ch.zhaw.pm2.multichat.protocol.NetworkHandler;
 
 import java.io.EOFException;
 import java.io.IOException;
 import java.net.SocketException;
-import java.util.HashMap;
 import java.util.Map;
 import java.util.Objects;
 import java.util.Scanner;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.concurrent.locks.Condition;
+import java.util.concurrent.locks.ReentrantLock;
 
-import static ch.zhaw.pm2.multichat.server.ServerConnectionHandler.State.*;
 
-public class ServerConnectionHandler implements Runnable{
+
+public class ServerConnectionHandler extends ConnectionHandler implements Runnable{
     private static final AtomicInteger connectionCounter = new AtomicInteger(0);
     private final int connectionId = connectionCounter.incrementAndGet();
-    private final NetworkHandler.NetworkConnection<String> connection;
     private final Map<String,ServerConnectionHandler> connectionRegistry;
 
-    // Data types used for the Chat Protocol
+    private ReentrantLock mutex;
-    private static final String DATA_TYPE_CONNECT = "CONNECT";
-    private static final String DATA_TYPE_CONFIRM = "CONFIRM";
-    private static final String DATA_TYPE_DISCONNECT = "DISCONNECT";
-    private static final String DATA_TYPE_MESSAGE = "MESSAGE";
-    private static final String DATA_TYPE_ERROR = "ERROR";
 
-    private static final String USER_NONE = "";
+    private Condition nameComplete;
-    private static final String USER_ALL = "*";
 
     private String userName = "Anonymous-"+connectionId;
     private State state = NEW;
@@ -38,28 +34,31 @@ public class ServerConnectionHandler implements Runnable{
         startReceiving();
     }
 
-    enum State {
-        NEW, CONNECTED, DISCONNECTED;
-    }
-
     public ServerConnectionHandler(NetworkHandler.NetworkConnection<String> connection,
-                                   Map<String,ServerConnectionHandler> registry) {
+                                   Map<String,ServerConnectionHandler> registry, ReentrantLock mutex, Condition nameComplete) {
+        super();
+        setConnection(connection);
         Objects.requireNonNull(connection, "Connection must not be null");
         Objects.requireNonNull(registry, "Registry must not be null");
-        this.connection = connection;
         this.connectionRegistry = registry;
+        this.mutex = mutex;
+        this.nameComplete = nameComplete;
     }
 
     public String getUserName() {
         return this.userName;
     }
 
-    public void startReceiving() {
+    public State getState() {
-        System.out.println("Starting Connection Handler for " + userName);
+        return state;
+    }
+
+    private void startReceiving() {
+            System.out.println("Starting Connection Handler for new User");
             try {
                 System.out.println("Start receiving data...");
-            while (connection.isAvailable()) {
+                while (getConnection().isAvailable() && !(state == ERROR)) {
-                String data = connection.receive();
+                    String data = getConnection().receive();
                     processData(data);
                 }
                 System.out.println("Stopped recieving data");
@@ -71,75 +70,100 @@ public class ServerConnectionHandler implements Runnable{
                 System.out.println("Connection terminated by remote");
                 connectionRegistry.remove(userName);
                 System.out.println("Unregistered because client connection terminated: " + userName + " " + e.getMessage());
-        } catch(IOException e) {
+            } catch (IOException e) {
                 System.err.println("Communication error: " + e);
-        } catch(ClassNotFoundException e) {
+            } catch (ClassNotFoundException e) {
                 System.err.println("Received object of unknown type: " + e.getMessage());
             }
+        if (state == ERROR) {
+            System.out.println("Stopping Connection Handler for Rejected Client");
+        } else {
             System.out.println("Stopping Connection Handler for " + userName);
         }
 
-    public void stopReceiving() {
+    }
+
+    private void stopReceiving() {
         System.out.println("Closing Connection Handler for " + userName);
         try {
             System.out.println("Stop receiving data...");
-            connection.close();
+            getConnection().close();
             System.out.println("Stopped receiving data.");
         } catch (IOException e) {
-            System.err.println("Failed to close connection." + e);
+            System.err.println("Failed to close connection." + e.getMessage());
         }
         System.out.println("Closed Connection Handler for " + userName);
     }
 
     private void processData(String data)  {
         try {
-            // parse data content
             Scanner scanner = new Scanner(data);
-            String sender = null;
+            StringBuilder sender = new StringBuilder();
-            String reciever = null;
+            StringBuilder reciever = new StringBuilder();
-            String type = null;
+            StringBuilder type = new StringBuilder();
-            String payload = null;
+            StringBuilder payload = new StringBuilder();
-            if (scanner.hasNextLine()) {
+            super.processData(scanner,sender,reciever,type,payload);
-                sender = scanner.nextLine();
-            } else {
-                throw new ChatProtocolException("No Sender found");
-            }
-            if (scanner.hasNextLine()) {
-                reciever = scanner.nextLine();
-            } else {
-                throw new ChatProtocolException("No Reciever found");
-            }
-            if (scanner.hasNextLine()) {
-                type = scanner.nextLine();
-            } else {
-                throw new ChatProtocolException("No Type found");
-            }
-            if (scanner.hasNextLine()) {
-                payload = scanner.nextLine();
-            }
 
             // dispatch operation based on type parameter
-            if (type.equals(DATA_TYPE_CONNECT)) {
+            if (type.toString().equals(getDataTypeConnect())) {
-                if (this.state != NEW) throw new ChatProtocolException("Illegal state for connect request: " + state);
+                caseConnect(sender.toString());
-                if (sender == null || sender.isBlank()) sender = this.userName;
+            } else if (type.toString().equals(getDataTypeConfirm())) {
-                if (connectionRegistry.containsKey(sender))
-                    throw new ChatProtocolException("User name already taken: " + sender);
-                this.userName = sender;
-                connectionRegistry.put(userName, this);
-                sendData(USER_NONE, userName, DATA_TYPE_CONFIRM, "Registration successfull for " + userName);
-                this.state = CONNECTED;
-            } else if (type.equals(DATA_TYPE_CONFIRM)) {
                 System.out.println("Not expecting to receive a CONFIRM request from client");
-            } else if (type.equals(DATA_TYPE_DISCONNECT)) {
+            } else if (type.toString().equals(getDataTypeDisconnect())) {
+                caseDisconnect();
+            } else if (type.toString().equals(getDataTypeMessage())) {
+                caseMessage(sender.toString(), reciever.toString(), type.toString(), payload.toString());
+            } else if (type.toString().equals(getDataTypeError())) {
+                System.err.println("Received error from client (" + sender + "): " + payload);
+            } else {
+                System.err.println("Unknown data type received: " + type);
+
+            }
+        } catch(ChatProtocolException e) {
+            System.out.println("Error while processing data " + e.getMessage());
+            sendData(USER_NONE, userName, getDataTypeError(), e.getMessage());
+        }
+    }
+
+    private void caseConnect(String sender) throws ChatProtocolException {
+        if (this.state != NEW) throw new ChatProtocolException("Illegal state for connect request: " + state);
+        if (sender.isBlank()) sender = this.userName;
+        if (connectionRegistry.containsKey(sender)) {
+            mutex.lock();
+            try {
+                state = ERROR;
+                nameComplete.signal();
+            }
+            finally {
+                mutex.unlock();
+            }
+            throw new ChatProtocolException("User name already taken: " + sender);
+        }
+        mutex.lock();
+        try {
+            this.userName = sender.toString();
+            nameComplete.signal();
+        }
+        finally {
+            mutex.unlock();
+        }
+        connectionRegistry.put(userName, this);
+        sendData(USER_NONE, userName, getDataTypeConfirm(), "Registration successfull for " + userName);
+        this.state = CONNECTED;
+    }
+
+    private void caseDisconnect() throws ChatProtocolException {
         if (state == DISCONNECTED)
             throw new ChatProtocolException("Illegal state for disconnect request: " + state);
         if (state == CONNECTED) {
             connectionRegistry.remove(this.userName);
         }
-                sendData(USER_NONE, userName, DATA_TYPE_CONFIRM, "Confirm disconnect of " + userName);
+        sendData(USER_NONE, userName, getDataTypeConfirm(), "Confirm disconnect of " + userName);
         this.state = DISCONNECTED;
         this.stopReceiving();
-            } else if (type.equals(DATA_TYPE_MESSAGE)) {
+    }
+
+    private void caseMessage(String sender, String reciever, String type, String payload) throws ChatProtocolException{
         if (state != CONNECTED) throw new ChatProtocolException("Illegal state for message request: " + state);
         if (USER_ALL.equals(reciever)) {
             for (ServerConnectionHandler handler : connectionRegistry.values()) {
@@ -149,39 +173,11 @@ public class ServerConnectionHandler implements Runnable{
             ServerConnectionHandler handler = connectionRegistry.get(reciever);
             if (handler != null) {
                 handler.sendData(sender, reciever, type, payload);
+                if(!reciever.equals(sender)){
+                    sendData(sender, reciever, type, payload); //send message to sender if it's a direct message and sender is not receiver.
+                }
             } else {
-                        this.sendData(USER_NONE, userName, DATA_TYPE_ERROR, "Unknown User: " + reciever);
+                this.sendData(USER_NONE, userName, getDataTypeError(), "Unknown User: " + reciever);
-                    }
-                }
-            } else if (type.equals(DATA_TYPE_ERROR)) {
-                System.err.println("Received error from client (" + sender + "): " + payload);
-            } else {
-                System.err.println("Unknown data type received: " + type);
-
-            }
-        } catch(ChatProtocolException e) {
-            System.out.println("Error while processing data" + e.getMessage());
-            sendData(USER_NONE, userName, DATA_TYPE_ERROR, e.getMessage());
-        }
-    }
-
-    public void sendData(String sender, String receiver, String type, String payload) {
-        if (connection.isAvailable()) {
-            new StringBuilder();
-            String data = new StringBuilder()
-                .append(sender+"\n")
-                .append(receiver+"\n")
-                .append(type+"\n")
-                .append(payload+"\n")
-                .toString();
-            try {
-                connection.send(data);
-            } catch (SocketException e) {
-                System.out.println("Connection closed: " + e.getMessage());
-            } catch (EOFException e) {
-                System.out.println("Connection terminated by remote");
-            } catch(IOException e) {
-                System.out.println("Communication error: " + e.getMessage());
             }
         }
     }