atualizando o arquivo documentation.md

- Login.commitEdit() no JSpinner para capturar porta digitada manualmente
- Main.java agora exibe o Login antes de criar o MainWindow
- MenuBar aplica os valores do Login no MainWindow via setUserName/setPort
- MainWindow: campos userName/port deixam de ser final; setPort() reconecta o socket
- Socket.java ganha close() para permitir reconexão limpa em nova porta

.gitignore

@@ -0,0 +1,7 @@
+/pitiupi/build/
+/pitiupi/dist/
+/pitiupi.chat/build/
+/pitiupi.chat/dist/
+/pitiupi.chat/nbproject/private/
+/pitiupi.screenCast/build/
+/pitiupi.screenCast/dist/

.idea/workspace.xml

@@ -4,29 +4,7 @@
     <option name="autoReloadType" value="SELECTIVE" />
   </component>
   <component name="ChangeListManager">
-    <list default="true" id="62118a1b-608f-4144-b29c-cf46419ca676" name="Changes" comment="">
+    <list default="true" id="62118a1b-608f-4144-b29c-cf46419ca676" name="Changes" comment="" />
-      <change afterPath="$PROJECT_DIR$/pitiupi/Documentation.md" afterDir="false" />
-      <change afterPath="$PROJECT_DIR$/pitiupi/PluginTutorial.md" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi.chat/build/built-jar.properties" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi.chat/build/built-jar.properties" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi.chat/dist/pitiupi.chat.jar" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi.chat/dist/pitiupi.chat.jar" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi.screenCast/build/built-jar.properties" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi.screenCast/build/built-jar.properties" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi.screenCast/dist/pitiupi.screenCast.jar" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi.screenCast/dist/pitiupi.screenCast.jar" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/.netbeans_automatic_build" beforeDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/.netbeans_update_resources" beforeDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/GUI/Login.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/GUI/Login.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/GUI/MainWindow.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/GUI/MainWindow.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/GUI/MenuBar.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/GUI/MenuBar.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/Main$1.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/Main$1.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/Main.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/Main.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/control/PluginLoader.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/control/PluginLoader.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/net/Socket.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/net/Socket.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/plugin/Plugin.class" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/build/classes/pitiupi/plugin/Plugin.class" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/dist/README.TXT" beforeDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/dist/pitiupi.jar" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/dist/pitiupi.jar" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/plugins/pitiupi.chat.jar" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/plugins/pitiupi.chat.jar" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/plugins/pitiupi.screenCast.jar" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/plugins/pitiupi.screenCast.jar" afterDir="false" />
-      <change beforePath="$PROJECT_DIR$/pitiupi/src/pitiupi/GUI/MenuBar.java" beforeDir="false" afterPath="$PROJECT_DIR$/pitiupi/src/pitiupi/GUI/MenuBar.java" afterDir="false" />
-    </list>
     <option name="SHOW_DIALOG" value="false" />
     <option name="HIGHLIGHT_CONFLICTS" value="true" />
     <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
@@ -43,20 +21,20 @@
     <option name="hideEmptyMiddlePackages" value="true" />
     <option name="showLibraryContents" value="true" />
   </component>
-  <component name="PropertiesComponent"><![CDATA[{
+  <component name="PropertiesComponent">{
-  "keyToString": {
+  &quot;keyToString&quot;: {
-    "Application.Main.executor": "Run",
+    &quot;Application.Main.executor&quot;: &quot;Run&quot;,
-    "ModuleVcsDetector.initialDetectionPerformed": "true",
+    &quot;ModuleVcsDetector.initialDetectionPerformed&quot;: &quot;true&quot;,
-    "RunOnceActivity.ShowReadmeOnStart": "true",
+    &quot;RunOnceActivity.ShowReadmeOnStart&quot;: &quot;true&quot;,
-    "RunOnceActivity.TerminalTabsStorage.copyFrom.TerminalArrangementManager.252": "true",
+    &quot;RunOnceActivity.TerminalTabsStorage.copyFrom.TerminalArrangementManager.252&quot;: &quot;true&quot;,
-    "RunOnceActivity.git.unshallow": "true",
+    &quot;RunOnceActivity.git.unshallow&quot;: &quot;true&quot;,
-    "git-widget-placeholder": "feature/help-and-documentation",
+    &quot;git-widget-placeholder&quot;: &quot;feature/help-and-documentation&quot;,
-    "ignore.virus.scanning.warn.message": "true",
+    &quot;ignore.virus.scanning.warn.message&quot;: &quot;true&quot;,
-    "kotlin-language-version-configured": "true",
+    &quot;kotlin-language-version-configured&quot;: &quot;true&quot;,
-    "last_opened_file_path": "C:/Users/extre/OneDrive/Documentos/Faculdade/2026_02/Monitoria/Pitiupi",
+    &quot;last_opened_file_path&quot;: &quot;C:/Users/extre/OneDrive/Documentos/Faculdade/2026_02/Monitoria/Pitiupi&quot;,
-    "settings.editor.selected.configurable": "preferences.keymap"
+    &quot;settings.editor.selected.configurable&quot;: &quot;preferences.keymap&quot;
   }
-}]]></component>
+}</component>
   <component name="RecentsManager">
     <key name="CopyFile.RECENT_KEYS">
       <recent name="C:\Users\extre\OneDrive\Documentos\Faculdade\2026_02\Monitoria\Pitiupi\pitiupi\plugins" />

pitiupi.chat/src/pitiupi/chat/GUI/ChatWindow.java

@@ -94,7 +94,7 @@ public class ChatWindow extends javax.swing.JDialog {
         if (jTextArea1.getText().trim().length() == 0) {
             return;
         }
-        ChatMessage message = new ChatMessage(mainWindow.getName(), jTextArea1.getText());
+        ChatMessage message = new ChatMessage(mainWindow.getUserName(), jTextArea1.getText());
         this.sendChatMessage(message);
         jTextArea1.setText("");
     }

pitiupi.screenCast/.idea/workspace.xml

@@ -0,0 +1,61 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="AutoImportSettings">
+    <option name="autoReloadType" value="SELECTIVE" />
+  </component>
+  <component name="ChangeListManager">
+    <list default="true" id="083e72ce-fa9b-4ddf-a0ef-24105aa3eabb" name="Changes" comment="">
+      <change afterPath="$PROJECT_DIR$/../pitiupi.quiz/src/META-INF/services/pitiupi.plugin.Plugin" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/../pitiupi.quiz/src/pitiupi/GUI/QuizWindow.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/../pitiupi.quiz/src/pitiupi/control/Pergunta.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/../pitiupi.quiz/src/pitiupi/control/Quiz.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/../pitiupi.quiz/src/pitiupi/net/QuizMessage.java" afterDir="false" />
+      <change afterPath="$PROJECT_DIR$/../pitiupi.quiz/src/pitiupi/plugin/Quiz.java" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/../.idea/workspace.xml" beforeDir="false" afterPath="$PROJECT_DIR$/../.idea/workspace.xml" afterDir="false" />
+      <change beforePath="$PROJECT_DIR$/src/pitiupi/screenCast/net/ScreenCastMessage.java" beforeDir="false" afterPath="$PROJECT_DIR$/src/pitiupi/screenCast/net/ScreenCastMessage.java" afterDir="false" />
+    </list>
+    <option name="SHOW_DIALOG" value="false" />
+    <option name="HIGHLIGHT_CONFLICTS" value="true" />
+    <option name="HIGHLIGHT_NON_ACTIVE_CHANGELIST" value="false" />
+    <option name="LAST_RESOLUTION" value="IGNORE" />
+  </component>
+  <component name="Git.Settings">
+    <option name="RECENT_GIT_ROOT_PATH" value="$PROJECT_DIR$/.." />
+  </component>
+  <component name="ProjectColorInfo"><![CDATA[{
+  "associatedIndex": 7
+}]]></component>
+  <component name="ProjectId" id="3Gs0wFaRD4HyhP9VXLUWBeq0qTL" />
+  <component name="ProjectViewState">
+    <option name="hideEmptyMiddlePackages" value="true" />
+    <option name="showLibraryContents" value="true" />
+  </component>
+  <component name="PropertiesComponent"><![CDATA[{
+  "keyToString": {
+    "ModuleVcsDetector.initialDetectionPerformed": "true",
+    "RunOnceActivity.ShowReadmeOnStart": "true",
+    "RunOnceActivity.git.unshallow": "true",
+    "git-widget-placeholder": "QuizPlugin",
+    "kotlin-language-version-configured": "true",
+    "last_opened_file_path": "C:/Users/extre/OneDrive/Documentos/Faculdade/2026_02/Monitoria/Pitiupi/pitiupi.screenCast",
+    "settings.editor.selected.configurable": "preferences.keymap"
+  }
+}]]></component>
+  <component name="SharedIndexes">
+    <attachedChunks>
+      <set>
+        <option value="bundled-jdk-9823dce3aa75-bf35d07a577b-intellij.indexing.shared.core-IU-252.28539.54" />
+      </set>
+    </attachedChunks>
+  </component>
+  <component name="TaskManager">
+    <task active="true" id="Default" summary="Default task">
+      <changelist id="083e72ce-fa9b-4ddf-a0ef-24105aa3eabb" name="Changes" comment="" />
+      <created>1784745206049</created>
+      <option name="number" value="Default" />
+      <option name="presentableId" value="Default" />
+      <updated>1784745206049</updated>
+    </task>
+    <servers />
+  </component>
+</project>

pitiupi/docs/Documentation.md

@@ -60,7 +60,7 @@ O método `send()` recebe uma mensagem já serializada em bytes e cria um
 
 De forma geral, o socket atua apenas como mecanismo de transporte das mensagens. 
 A única exceção é o tratamento de HeartbeatMessage, utilizado pela infraestrutura
-da aplicação para manter a lista de usuários ativos.
+da aplicação para manter a lista de peers ativos.
 
 #### Recepção de mensagens
 
@@ -98,9 +98,15 @@ comportamentos necessários para cada funcionalidade.
 O mecanismo de heartbeat é utilizado para identificar quais usuários estão
 ativos na rede.
 
-A aplicação envia periodicamente uma `HeartbeatMessage` contendo informações
+A aplicação envia periodicamente uma `HeartbeatMessage` contendo
-do usuário e um timestamp. Quando outra instância recebe essa mensagem, o
+informações do usuário, um identificador único da instância da aplicação
-`HeartbeatManager` atualiza o registro do usuário correspondente.
+e um timestamp. Quando outra instância recebe essa mensagem, o `HeartbeatManager`
+registra ou atualiza o peer correspondente, utilizando o identificador
+da instância para diferenciá-lo das demais.
+
+Um peer é considerado inativo quando permanece mais de 15 segundos
+sem receber um novo heartbeat. O `HeartbeatManager` então remove o peer
+da lista e notifica os listeners sobre a alteração.
 
 O fluxo de heartbeat é independente das mensagens dos plugins:
 
@@ -109,7 +115,7 @@ O fluxo de heartbeat é independente das mensagens dos plugins:
 3. O `Socket` transmite a mensagem pela rede multicast.
 4. O `Socket` identifica mensagens de heartbeat recebidas e encaminha ao
    `HeartbeatManager`.
-5. O `HeartbeatManager` atualiza a lista de usuários ativos e notifica os
+5. O `HeartbeatManager` atualiza a lista de peers ativos e notifica os
    listeners.
 
 ## Sistema de plugins

pitiupi/src/pitiupi/GUI/Login.java

@@ -1,8 +1,3 @@
-/*
- * To change this license header, choose License Headers in Project Properties.
- * To change this template file, choose Tools | Templates
- * and open the template in the editor.
- */
 package pitiupi.GUI;
 
 import java.awt.BorderLayout;
@@ -11,6 +6,7 @@ import java.awt.GridBagConstraints;
 import java.awt.GridBagLayout;
 import java.awt.Insets;
 import java.awt.event.ActionEvent;
+import java.util.prefs.Preferences;
 
 import javax.swing.JButton;
 import javax.swing.JDialog;
@@ -26,9 +22,14 @@ import javax.swing.JTextField;
  * multicast que será utilizada pela comunicação.</p>
  *
  * @author flavio
+ * @author tony
  */
 public final class Login extends JDialog {
 
+    private static final Preferences prefs = Preferences.userNodeForPackage(Login.class);
+    private static final String PREF_NOME = "lastUserName";
+    private static final String PREF_PORTA = "lastPort";
+
     JLabel nameLabel = new JLabel("Name: ");
     JLabel portLabel = new JLabel("Port: ");
 
@@ -47,8 +48,12 @@ public final class Login extends JDialog {
     public void initComponents() {
         this.setTitle("Login");
 
-        portField.setModel(new javax.swing.SpinnerNumberModel(8000, 8000, 9000, 1));
+
-        nameField.setText(System.getProperty("user.name"));
+        String nomeSalvo = prefs.get(PREF_NOME, System.getProperty("user.name"));
+        int portaSalva = prefs.getInt(PREF_PORTA, 8000);
+
+        portField.setModel(new javax.swing.SpinnerNumberModel(portaSalva, 8000, 9000, 1));
+        nameField.setText(nomeSalvo);
 
         JPanel topPanel = new JPanel(new GridBagLayout());
         JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT));
@@ -87,6 +92,15 @@ public final class Login extends JDialog {
         this.add(buttonPanel, BorderLayout.SOUTH);
 
         okButton.addActionListener((ActionEvent e) -> {
+            try {
+                portField.commitEdit();
+            } catch (java.text.ParseException ex) {
+                return;
+            }
+
+            prefs.put(PREF_NOME, nameField.getText());
+            prefs.putInt(PREF_PORTA, (Integer) portField.getValue());
+
             Login.this.setVisible(false);
         });
 

pitiupi/src/pitiupi/GUI/MainWindow.java

@@ -41,8 +41,8 @@ public class MainWindow extends javax.swing.JFrame {
 
     private Socket socket;
 
-    private final String userName;
+    private String userName;
-    private final int port;
+    private  int port;
 
     private PluginLoader pluginManager;
     private final List<Plugin> plugins;
@@ -137,4 +137,28 @@ public class MainWindow extends javax.swing.JFrame {
     public List<Plugin> getPlugins() {
         return plugins;
     }
+
+    public void setUserName(String userName) {
+        this.userName = userName;
+        updateStatus();
+    }
+
+    public void setPort(int port) {
+        this.port = port;
+        reconnect();
+        updateStatus();
+    }
+
+    private void updateStatus() {
+        this.status.setText("Connected on port " + this.port + " name " + this.userName);
+    }
+
+    private void reconnect() {
+        if (this.socket != null) {
+            this.socket.close();
+        }
+        this.socket = new Socket(this);
+        this.socket.start();
+    }
+
 }

pitiupi/src/pitiupi/GUI/MenuBar.java

@@ -16,6 +16,8 @@ import javax.swing.JMenuBar;
  *
  * @author flavio
  * @author Gustavo
+ * @author tony
+ *
  */
 public class MenuBar extends JMenuBar {
 
@@ -27,6 +29,11 @@ public class MenuBar extends JMenuBar {
     private javax.swing.JMenuItem exitMenu;
     private final MainWindow mainWindow;
 
+    /**
+     * Cria a barra de menus principal da aplicação.
+     *
+     * @param mainWindow mainWindow janela principal da aplicação utilizada para executar
+     */
     public MenuBar(MainWindow mainWindow) {
         this.mainWindow = mainWindow;
         this.initComponents();
@@ -67,9 +74,14 @@ public class MenuBar extends JMenuBar {
         mainWindow.exit();
     }
 
-    private void setupMenuActionPerformed(java.awt.event.ActionEvent evt) {
+
+   private void setupMenuActionPerformed(java.awt.event.ActionEvent evt) {
         Login login = new Login();
         login.setVisible(true);
+
+        mainWindow.setUserName(login.getName());
+        mainWindow.setPort(login.getPort());
+
         login.dispose();
     }
 

pitiupi/src/pitiupi/Main.java

@@ -12,6 +12,7 @@ import java.util.logging.Logger;
 /**
  *
  * @author flavio
+ * @author tony
  */
 public class Main {
     /**
@@ -39,16 +40,17 @@ public class Main {
         } catch (javax.swing.UnsupportedLookAndFeelException ex) {
             java.util.logging.Logger.getLogger(pitiupi.GUI.MainWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
         }
-        //</editor-fold>
 
-        /* Create and display the form */
         java.awt.EventQueue.invokeLater(new Runnable() {
             @Override
             public void run() {
+                pitiupi.GUI.Login login = new pitiupi.GUI.Login();
+                login.setVisible(true); 
+
                 pitiupi.GUI.MainWindow main;
-                main = new pitiupi.GUI.MainWindow(System.getProperty("user.name"), 8000);
+                main = new pitiupi.GUI.MainWindow(login.getName(), login.getPort());
                 main.setVisible(true);
-            }
+            }   
         });
     }
 

pitiupi/src/pitiupi/control/HeartbeatManager.java

@@ -14,6 +14,7 @@ import java.util.logging.Level;
 import java.util.logging.Logger;
 import pitiupi.GUI.MainWindow;
 import pitiupi.net.HeartbeatMessage;
+import java.util.UUID;
 /**
  * Gerencia o mecanismo de heartbeat da aplicação.
  *
@@ -32,17 +33,30 @@ public class HeartbeatManager {
     private final Map<String, PeerInfo> peers = new ConcurrentHashMap<>();
     private final List<PeerListener> listeners = new CopyOnWriteArrayList<>();
     private ScheduledExecutorService scheduler;
+    private final String instanceId = UUID.randomUUID().toString();
 
+    /**
+     * Cria um gerenciador de heartbeat associado à janela principal da aplicação.
+     *
+     * @param mainWindow janela principal utilizada para obter o nome do usuário
+     * e o socket de comunicação.
+     */
     public HeartbeatManager(MainWindow mainWindow) {
         this.mainWindow = mainWindow;
     }
 
+    /**
+     * Inicia o mecanismo de heartbeat.
+     */
     public void start() {
         scheduler = Executors.newScheduledThreadPool(1);
         scheduler.scheduleAtFixedRate(this::announce, 0, HEARTBEAT_INTERVAL_MS, TimeUnit.MILLISECONDS);
         scheduler.scheduleAtFixedRate(this::checkTimeouts, HEARTBEAT_INTERVAL_MS, HEARTBEAT_INTERVAL_MS, TimeUnit.MILLISECONDS);
     }
 
+    /**
+     * Para o mecanismo de heartbeat e encerra as tarefas agendadas.
+     */
     public void stop() {
         if (scheduler != null) {
             scheduler.shutdownNow();
@@ -51,7 +65,7 @@ public class HeartbeatManager {
 
     private void announce() {
         try {
-            HeartbeatMessage msg = new HeartbeatMessage(mainWindow.getUserName());
+            HeartbeatMessage msg = new HeartbeatMessage(mainWindow.getUserName(), instanceId);
             mainWindow.getSocket().send(msg.toByteArray());
         } catch (IOException ex) {
             Logger.getLogger(HeartbeatManager.class.getName()).log(Level.WARNING, "Falha ao enviar heartbeat", ex);
@@ -62,21 +76,22 @@ public class HeartbeatManager {
     /**
      * Processa uma mensagem de heartbeat recebida de outro usuário.
      *
-     * <p>Atualiza a informação do peer correspondente e notifica os listeners
+     * <p>Atualiza o momento da última atividade do peer correspondente e notifica os listeners
-     * caso um novo usuário seja identificado.</p>
+     * caso outra instância da aplicação seja identificada.</p>
      *
      * <p>Mensagens de heartbeat enviadas pela própria aplicação são ignoradas.</p>
      *
      * @param msg mensagem de heartbeat recebida.
      * @param from endereço de rede do usuário que enviou a mensagem.
      */
+
     public void receiveHeartbeat(HeartbeatMessage msg, InetAddress from) {
         // ignora o próprio heartbeat 
-        if (msg.getUserName().equals(mainWindow.getUserName())) {
+        if (msg.getInstanceId().equals(instanceId) ) {
             return;
         }
 
-        String key = from.getHostAddress() + "#" + msg.getUserName();
+        String key =  msg.getInstanceId();
         boolean isNew = !peers.containsKey(key);
 
         PeerInfo peer = peers.computeIfAbsent(key, k -> new PeerInfo(msg.getUserName(), from, msg.getTimestamp()));
@@ -115,10 +130,20 @@ public class HeartbeatManager {
         l.onPeersChanged(new ArrayList<>(peers.values()));
     }
 
+    /**
+     * Remove um listener previamente registrado.
+     *
+     * @param l listener que deixará de receber atualizações.
+     */
     public void removePeerListener(PeerListener l) {
         listeners.remove(l);
     }
 
+    /**
+     * Retorna uma cópia da lista atual de peers conhecidos.
+     *
+     * @return lista contendo os peers atualmente conhecidos.
+     */
     public List<PeerInfo> getPeers() {
         return new ArrayList<>(peers.values());
     }

pitiupi/src/pitiupi/net/HeartbeatMessage.java

@@ -11,9 +11,11 @@ public class HeartbeatMessage extends Message {
 
     private final String userName;
     private final long timestamp;
+    private final String instanceId; 
 
-    public HeartbeatMessage(String userName) {
+    public HeartbeatMessage(String userName, String instanceId) {
         this.userName = userName;
+        this.instanceId = instanceId;
         this.timestamp = System.currentTimeMillis();
     }
 
@@ -24,4 +26,8 @@ public class HeartbeatMessage extends Message {
     public long getTimestamp() {
         return timestamp;
     }
+
+    public String getInstanceId() {
+        return instanceId;
+    }
 }

pitiupi/src/pitiupi/net/Socket.java

@@ -20,7 +20,7 @@ import pitiupi.plugin.Plugin;
 import pitiupi.net.HeartbeatMessage;
 
 /**
- * Responsável pela comunicação multicast entre a aplicação e os plugins.
+ * "Responsável pela comunicação multicast da aplicação e pelo encaminhamento de mensagens aos plugins."
  *
  * <p>Esta classe gerencia o envio e o recebimento de mensagens, além de
  * manter a conexão com o grupo multicast utilizado pela aplicação.</p>
@@ -33,6 +33,7 @@ public class Socket extends Thread {
     private MulticastSocket multicastSocket;
     private InetAddress address;
     private MainWindow main;
+    private volatile boolean running = true;
     public final static String INET_ADDR = "224.0.0.3";
 
     /**
@@ -71,6 +72,22 @@ public class Socket extends Thread {
         multicastSocket.send(msgPacket);
     }
 
+    /**
+     * Encerra a comunicação multicast e interrompe a recepção de mensagens.
+     */
+    public void close() {
+        running = false;
+        if (multicastSocket != null) {
+            try {
+                multicastSocket.leaveGroup(address);
+            } catch (IOException ex) {
+
+            }
+            multicastSocket.close();
+        }
+    }
+
+
     /**
      * Inicia o loop de recepção de mensagens da aplicação.
      *
@@ -84,16 +101,21 @@ public class Socket extends Thread {
      */
     public void receive() throws UnknownHostException, IOException, ClassNotFoundException {
         byte[] buf = new byte[256000];
-        while (true) {
+        while (running) {
             DatagramPacket msgPacket = new DatagramPacket(buf, buf.length);
-            multicastSocket.receive(msgPacket);
+            try {
-
+                multicastSocket.receive(msgPacket);
+            } catch (IOException ex) {
+                if (!running) {
+                    break;
+                }
+                throw ex;
+            }
             HeartbeatMessage heartbeat = tryParseHeartbeat(msgPacket.getData());
             if (heartbeat != null) {
                 main.getHeartbeatManager().receiveHeartbeat(heartbeat, msgPacket.getAddress());
                 continue;
             }
-
             for (Plugin plugin : main.getPlugins()) {
                 System.out.println(msgPacket.getAddress().toString());
                 plugin.receiveMessage(msgPacket.getData());