Support message buffering before initial connect

org.eclipse.paho.android.sample/src/main/java/org/eclipse/paho/android/sample/activity/Connection.java

@@ -11,6 +11,7 @@
 import org.eclipse.paho.android.sample.model.ReceivedMessage;
 import org.eclipse.paho.android.sample.model.Subscription;
 import org.eclipse.paho.android.service.MqttAndroidClient;
+import org.eclipse.paho.client.mqttv3.DisconnectedBufferOptions;
 import org.eclipse.paho.client.mqttv3.MqttConnectOptions;
 import org.eclipse.paho.client.mqttv3.MqttException;
 import org.eclipse.paho.client.mqttv3.MqttMessage;
@@ -84,6 +85,10 @@ public class Connection {
      * True if this connection is secured using TLS
      **/
     private boolean tlsConnection = true;
+    /**
+     * Whether the connection should enable the buffer
+     **/
+    private boolean bufferEnabled = true;
     /**
      * Persistence id, used by {@link Persistence}
      **/
@@ -100,9 +105,10 @@ public class Connection {
      * @param context       The application context
      * @param client        The MqttAndroidClient which communicates with the service for this connection
      * @param tlsConnection true if the connection is secured by SSL
+     * @param bufferEnabled true if the connection buffer should be enabled
      */
     private Connection(String clientHandle, String clientId, String host,
-            int port, Context context, MqttAndroidClient client, boolean tlsConnection) {
+            int port, Context context, MqttAndroidClient client, boolean tlsConnection, boolean bufferEnabled) {
         //generate the client handle from its hash code
         this.clientHandle = clientHandle;
         this.clientId = clientId;
@@ -111,6 +117,7 @@ private Connection(String clientHandle, String clientId, String host,
         this.context = context;
         this.client = client;
         this.tlsConnection = tlsConnection;
+        this.bufferEnabled = bufferEnabled;
         history = new ArrayList<>();
         String sb = "Client: " + clientId + " created";
         addAction(sb);
@@ -125,9 +132,11 @@ private Connection(String clientHandle, String clientId, String host,
      * @param port          the port on the server which the client will attempt to connect to
      * @param context       the application context
      * @param tlsConnection true if the connection is secured by SSL
+     * @param bufferEnabled true if the connection buffer should be enabled
      * @return a new instance of <code>Connection</code>
      */
-    public static Connection createConnection(String clientHandle, String clientId, String host, int port, Context context, boolean tlsConnection) {
+    public static Connection createConnection(String clientHandle, String clientId, String host, int port, Context context, boolean tlsConnection,
+            boolean bufferEnabled) {
 
         String uri;
         if (tlsConnection) {
@@ -137,7 +146,15 @@ public static Connection createConnection(String clientHandle, String clientId,
         }
 
         MqttAndroidClient client = new MqttAndroidClient(context, uri, clientId);
-        return new Connection(clientHandle, clientId, host, port, context, client, tlsConnection);
+
+        // add buffer options
+        if (bufferEnabled) {
+            DisconnectedBufferOptions bufferOpts = new DisconnectedBufferOptions();
+            bufferOpts.setBufferEnabled(true);
+            client.setBufferOpts(bufferOpts);
+        }
+
+        return new Connection(clientHandle, clientId, host, port, context, client, tlsConnection, bufferEnabled);
     }
 
     public void updateConnection(String clientId, String host, int port, boolean tlsConnection) {
@@ -339,6 +356,15 @@ public int isSSL() {
         return tlsConnection ? 1 : 0;
     }
 
+    /**
+     * Determines if the connections buffer is enabled
+     *
+     * @return true buffer is enabled
+     */
+    public boolean isBufferEnabled() {
+        return bufferEnabled;
+    }
+
     /**
      * Assign a persistence ID to this object
      *

org.eclipse.paho.android.sample/src/main/java/org/eclipse/paho/android/sample/activity/EditConnectionFragment.java

@@ -35,6 +35,7 @@ public class EditConnectionFragment extends Fragment {
     private EditText serverHostname;
     private EditText serverPort;
     private Switch cleanSession;
+    private Switch buffer;
     private EditText username;
     private EditText password;
     private EditText tlsServerKey;
@@ -66,6 +67,7 @@ public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle sa
         serverPort = rootView.findViewById(R.id.add_connection_port);
         serverPort.setText("");
         cleanSession = rootView.findViewById(R.id.clean_session_switch);
+        buffer = rootView.findViewById(R.id.buffer_switch);
         username = rootView.findViewById(R.id.username);
         password = rootView.findViewById(R.id.password);
         tlsServerKey = rootView.findViewById(R.id.tls_server_key);
@@ -169,6 +171,13 @@ public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
             }
         });
 
+        buffer.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
+            @Override
+            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
+                formModel.setBuffer(isChecked);
+            }
+        });
+
         username.addTextChangedListener(new TextWatcher() {
             @Override
             public void beforeTextChanged(CharSequence s, int start, int count, int after) {
@@ -338,6 +347,7 @@ private void populateFromConnectionModel(ConnectionModel connectionModel) {
         serverHostname.setText(connectionModel.getServerHostName());
         serverPort.setText(Integer.toString(connectionModel.getServerPort()));
         cleanSession.setChecked(connectionModel.isCleanSession());
+        buffer.setChecked(connectionModel.isBufferEnabled());
         username.setText(connectionModel.getUsername());
         password.setText(connectionModel.getPassword());
         tlsServerKey.setText(connectionModel.getTlsServerKey());

org.eclipse.paho.android.sample/src/main/java/org/eclipse/paho/android/sample/activity/MainActivity.java

@@ -202,7 +202,7 @@ public void persistAndConnect(ConnectionModel model) {
         Log.i(TAG, "Persisting new connection:" + model.getClientHandle());
         Connection connection = Connection
                 .createConnection(model.getClientHandle(), model.getClientId(), model.getServerHostName(), model.getServerPort(), this, model
-                        .isTlsConnection());
+                        .isTlsConnection(), model.isBufferEnabled());
         connection.registerChangeListener(changeListener);
         connection.changeConnectionStatus(Connection.ConnectionStatus.CONNECTING);
 

org.eclipse.paho.android.sample/src/main/java/org/eclipse/paho/android/sample/internal/Persistence.java

@@ -85,6 +85,10 @@ public class Persistence extends SQLiteOpenHelper implements BaseColumns {
      * Table column for clean session
      **/
     private static final String COLUMN_CLEAN_SESSION = "cleanSession";
+    /**
+     * Table column for buffer
+     **/
+    private static final String COLUMN_BUFFER = "buffer";
     /** Table column for **/
 
     //last will
@@ -156,6 +160,7 @@ public class Persistence extends SQLiteOpenHelper implements BaseColumns {
                     COLUMN_USER_NAME + TEXT_TYPE + COMMA_SEP +
                     COLUMN_PASSWORD + TEXT_TYPE + COMMA_SEP +
                     COLUMN_CLEAN_SESSION + INT_TYPE + COMMA_SEP +
+                    COLUMN_BUFFER + INT_TYPE + COMMA_SEP +
                     COLUMN_TOPIC + TEXT_TYPE + COMMA_SEP +
                     COLUMN_MESSAGE + TEXT_TYPE + COMMA_SEP +
                     COLUMN_QOS + INT_TYPE + COMMA_SEP +
@@ -271,6 +276,7 @@ private ContentValues getValues(Connection connection) {
         //uses "condition ? trueValue: falseValue" for in line converting of values
         char[] password = conOpts.getPassword();
         values.put(COLUMN_CLEAN_SESSION, conOpts.isCleanSession() ? 1 : 0); //convert boolean to int and then put in values
+        values.put(COLUMN_BUFFER, connection.isBufferEnabled() ? 1 : 0); //convert boolean to int and then put in values
         values.put(COLUMN_PASSWORD, password != null ? String.valueOf(password) : null); //convert char[] to String
         values.put(COLUMN_MESSAGE, lastWill != null ? new String(lastWill.getPayload()) : null); // convert byte[] to string
         values.put(COLUMN_QOS, lastWill != null ? lastWill.getQos() : 0);
@@ -339,6 +345,7 @@ public List<Connection> restoreConnections(Context context) throws PersistenceEx
                 COLUMN_ssl,
                 COLUMN_KEEP_ALIVE,
                 COLUMN_CLEAN_SESSION,
+                COLUMN_BUFFER,
                 COLUMN_TIME_OUT,
                 COLUMN_USER_NAME,
                 COLUMN_PASSWORD,
@@ -393,6 +400,7 @@ public List<Connection> restoreConnections(Context context) throws PersistenceEx
 
             //get all values that need converting and convert integers to booleans in line using "condition ? trueValue : falseValue"
             boolean cleanSession = cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_CLEAN_SESSION)) == 1;
+            boolean bufferEnabled = cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_BUFFER)) == 1;
             boolean retained = cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_RETAINED)) == 1;
             boolean ssl = cursor.getInt(cursor.getColumnIndexOrThrow(COLUMN_ssl)) == 1;
 
@@ -410,7 +418,7 @@ public List<Connection> restoreConnections(Context context) throws PersistenceEx
             }
 
             //now create the connection object
-            connection = Connection.createConnection(clientHandle, clientID, host, port, context, ssl);
+            connection = Connection.createConnection(clientHandle, clientID, host, port, context, ssl, bufferEnabled);
             connection.addConnectionOptions(opts);
             connection.assignPersistenceId(id);
 

org.eclipse.paho.android.sample/src/main/java/org/eclipse/paho/android/sample/model/ConnectionModel.java

@@ -10,6 +10,7 @@ public class ConnectionModel {
     private String serverHostName = "iot.eclipse.org";
     private int serverPort = 1883;
     private boolean cleanSession = true;
+    private boolean buffer = true;
     private String username = "";
     private String password = "";
 
@@ -36,6 +37,7 @@ public ConnectionModel(Connection connection) {
         serverHostName = connection.getHostName();
         serverPort = connection.getPort();
         cleanSession = connection.getConnectionOptions().isCleanSession();
+        buffer = true; // unable to get buffer information from the connection...
 
         if (connection.getConnectionOptions().getUserName() == null) {
             username = "";
@@ -108,6 +110,14 @@ public void setCleanSession(boolean cleanSession) {
         this.cleanSession = cleanSession;
     }
 
+    public boolean isBufferEnabled() {
+        return buffer;
+    }
+
+    public void setBuffer(boolean buffer) {
+        this.buffer = buffer;
+    }
+
     public String getUsername() {
         return username;
     }

org.eclipse.paho.android.sample/src/main/res/layout/fragment_edit_connection.xml

@@ -115,20 +115,34 @@
             android:layout_below="@+id/port_group"/>
 
 
+        <!--                    Advanced Settings                    -->
+        <!--                    General Settings                     -->
+
+
         <Switch
             android:id="@+id/clean_session_switch"
             style="@style/Switch"
-            android:layout_below="@+id/divider3"
+            android:layout_alignParentLeft="true"
+            android:layout_alignParentStart="true"
+            android:layout_below="@+id/port_group"
             android:text="@string/add_connection_clean_session_label"/>
 
-        <!--                    Advanced Settings                    -->
-        <!--                    General Settings                     -->
-
+        <Switch
+            android:id="@+id/buffer_switch"
+            style="@style/Switch"
+            android:layout_width="wrap_content"
+            android:layout_height="wrap_content"
+            android:layout_alignParentLeft="true"
+            android:layout_alignParentStart="true"
+            android:layout_below="@+id/clean_session_switch"
+            android:text="@string/add_connection_buffer"/>
 
         <TextView
             android:id="@+id/advancedTextView"
             style="@style/HeaderText"
-            android:layout_below="@+id/clean_session_switch"
+            android:layout_alignParentLeft="true"
+            android:layout_alignParentStart="true"
+            android:layout_below="@+id/buffer_switch"
             android:text="@string/add_connection_advanced_label"/>
 
 

org.eclipse.paho.android.sample/src/main/res/values/strings.xml

@@ -103,6 +103,7 @@
 
     <!-- Message List Item -->
     <string name="message_topic">Topic: </string>
+    <string name="add_connection_buffer">Enable Message Buffer</string>
 
 
 </resources>