fix: typo fix in variable name and method name

netty-mqtt/src/main/java/org/thingsboard/mqtt/MqttChannelHandler.java

@@ -166,7 +166,7 @@ final class MqttChannelHandler extends SimpleChannelInboundHandler<MqttMessage>
         for (MqttPendingSubscription.MqttPendingHandler handler : pendingSubscription.getHandlers()) {
             MqttSubscription subscription = new MqttSubscription(pendingSubscription.getTopic(), handler.getHandler(), handler.isOnce());
             this.client.getSubscriptions().put(pendingSubscription.getTopic(), subscription);
-            this.client.getHandlerToSubscribtion().put(handler.getHandler(), subscription);
+            this.client.getHandlerToSubscription().put(handler.getHandler(), subscription);
         }
         this.client.getPendingSubscribeTopics().remove(pendingSubscription.getTopic());
 

netty-mqtt/src/main/java/org/thingsboard/mqtt/MqttClientImpl.java

@@ -55,7 +55,6 @@ import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.ConcurrentMap;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
-import java.util.function.BiConsumer;
 
 /**
  * Represents an MqttClientImpl connected to a single MQTT server. Will try to keep the connection going at all times
@@ -70,7 +69,7 @@ final class MqttClientImpl implements MqttClient {
     private final HashMultimap<String, MqttSubscription> subscriptions = HashMultimap.create();
     private final ConcurrentMap<Integer, MqttPendingSubscription> pendingSubscriptions = new ConcurrentHashMap<>();
     private final Set<String> pendingSubscribeTopics = new HashSet<>();
-    private final HashMultimap<MqttHandler, MqttSubscription> handlerToSubscribtion = HashMultimap.create();
+    private final HashMultimap<MqttHandler, MqttSubscription> handlerToSubscription = HashMultimap.create();
     private final AtomicInteger nextMessageId = new AtomicInteger(1);
 
     private final MqttClientConfig clientConfig;
@@ -166,7 +165,7 @@ final class MqttClientImpl implements MqttClient {
                     pendingPublishes.forEach((id, mqttPendingPublish) -> mqttPendingPublish.onChannelClosed());
                     pendingPublishes.clear();
                     pendingSubscribeTopics.clear();
-                    handlerToSubscribtion.clear();
+                    handlerToSubscription.clear();
                     scheduleConnectIfRequired(host, port, true);
                 });
             } else {
@@ -283,11 +282,11 @@ final class MqttClientImpl implements MqttClient {
     @Override
     public Future<Void> off(String topic, MqttHandler handler) {
         Promise<Void> future = new DefaultPromise<>(this.eventLoop.next());
-        for (MqttSubscription subscription : this.handlerToSubscribtion.get(handler)) {
+        for (MqttSubscription subscription : this.handlerToSubscription.get(handler)) {
             this.subscriptions.remove(topic, subscription);
         }
-        this.handlerToSubscribtion.removeAll(handler);
-        this.checkSubscribtions(topic, future);
+        this.handlerToSubscription.removeAll(handler);
+        this.checkSubscriptions(topic, future);
         return future;
     }
 
@@ -303,12 +302,12 @@ final class MqttClientImpl implements MqttClient {
         Promise<Void> future = new DefaultPromise<>(this.eventLoop.next());
         ImmutableSet<MqttSubscription> subscriptions = ImmutableSet.copyOf(this.subscriptions.get(topic));
         for (MqttSubscription subscription : subscriptions) {
-            for (MqttSubscription handSub : this.handlerToSubscribtion.get(subscription.getHandler())) {
+            for (MqttSubscription handSub : this.handlerToSubscription.get(subscription.getHandler())) {
                 this.subscriptions.remove(topic, handSub);
             }
-            this.handlerToSubscribtion.remove(subscription.getHandler(), subscription);
+            this.handlerToSubscription.remove(subscription.getHandler(), subscription);
         }
-        this.checkSubscribtions(topic, future);
+        this.checkSubscriptions(topic, future);
         return future;
     }
 
@@ -461,7 +460,7 @@ final class MqttClientImpl implements MqttClient {
         if (this.serverSubscriptions.contains(topic)) {
             MqttSubscription subscription = new MqttSubscription(topic, handler, once);
             this.subscriptions.put(topic, subscription);
-            this.handlerToSubscribtion.put(handler, subscription);
+            this.handlerToSubscription.put(handler, subscription);
             return this.channel.newSucceededFuture();
         }
 
@@ -484,7 +483,7 @@ final class MqttClientImpl implements MqttClient {
         return future;
     }
 
-    private void checkSubscribtions(String topic, Promise<Void> promise) {
+    private void checkSubscriptions(String topic, Promise<Void> promise) {
         if (!(this.subscriptions.containsKey(topic) && this.subscriptions.get(topic).size() != 0) && this.serverSubscriptions.contains(topic)) {
             MqttFixedHeader fixedHeader = new MqttFixedHeader(MqttMessageType.UNSUBSCRIBE, false, MqttQoS.AT_LEAST_ONCE, false, 0);
             MqttMessageIdVariableHeader variableHeader = getNewMessageId();
@@ -514,8 +513,8 @@ final class MqttClientImpl implements MqttClient {
         return pendingSubscribeTopics;
     }
 
-    HashMultimap<MqttHandler, MqttSubscription> getHandlerToSubscribtion() {
-        return handlerToSubscribtion;
+    HashMultimap<MqttHandler, MqttSubscription> getHandlerToSubscription() {
+        return handlerToSubscription;
     }
 
     Set<String> getServerSubscriptions() {