diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/CORSFilter.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/CORSFilter.java
index d5e19ae..bfade8a 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/CORSFilter.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/CORSFilter.java
@@ -31,10 +31,4 @@ public class CORSFilter implements Filter {
 
         chain.doFilter(req, res);
     }
-
-    @Override
-    public void init(FilterConfig filterConfig) {}
-
-    @Override
-    public void destroy() {}
 }
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTRequestFilter.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTRequestFilter.java
index 503f7cd..3cfc094 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTRequestFilter.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTRequestFilter.java
@@ -36,9 +36,9 @@ public class JWTRequestFilter extends OncePerRequestFilter {
             try {
                 username = jwtTokenUtils.getUsernameFromToken(jwtToken);
             } catch (IllegalArgumentException e) {
-                System.out.println("Unable to get JWT Token");
+                logger.info("Unable to get JWT Token");
             } catch (ExpiredJwtException e) {
-                System.out.println("JWT Token has expired");
+                logger.info("JWT Token has expired");
             }
         } else {
             logger.warn("JWT Token does not begin with Bearer String");
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTTokenUtils.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTTokenUtils.java
index 9d2d939..78e5e5e 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTTokenUtils.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/JWTTokenUtils.java
@@ -68,7 +68,7 @@ public class JWTTokenUtils {
      * @param userDetails user details to validate against
      * @return true if valid, false if not
      */
-    public Boolean validateToken(String token, UserDetails userDetails) {
+    public boolean validateToken(String token, UserDetails userDetails) {
         final String username = getUsernameFromToken(token);
         return (username.equals(userDetails.getUsername()) && !isTokenExpired(token));
     }
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactory.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactory.java
index dbe1331..d1d4e76 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactory.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactory.java
@@ -1,21 +1,5 @@
 package ch.usi.inf.sa4.sanmarinoes.smarthut.config;
 
-/*
- * Copyright (C) 2011 Google Inc.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
 import com.google.gson.Gson;
 import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
@@ -158,8 +142,8 @@ import java.util.Map;
 public final class RuntimeTypeAdapterFactory<T> implements TypeAdapterFactory {
     private final Class<?> baseType;
     private final String typeFieldName;
-    private final Map<String, Class<?>> labelToSubtype = new LinkedHashMap<String, Class<?>>();
-    private final Map<Class<?>, String> subtypeToLabel = new LinkedHashMap<Class<?>, String>();
+    private final Map<String, Class<?>> labelToSubtype = new LinkedHashMap<>();
+    private final Map<Class<?>, String> subtypeToLabel = new LinkedHashMap<>();
     private final boolean maintainType;
 
     private RuntimeTypeAdapterFactory(
@@ -179,7 +163,7 @@ public final class RuntimeTypeAdapterFactory<T> implements TypeAdapterFactory {
      */
     public static <T> RuntimeTypeAdapterFactory<T> of(
             Class<T> baseType, String typeFieldName, boolean maintainType) {
-        return new RuntimeTypeAdapterFactory<T>(baseType, typeFieldName, maintainType);
+        return new RuntimeTypeAdapterFactory<>(baseType, typeFieldName, maintainType);
     }
 
     /**
@@ -187,7 +171,7 @@ public final class RuntimeTypeAdapterFactory<T> implements TypeAdapterFactory {
      * the type field name. Type field names are case sensitive.
      */
     public static <T> RuntimeTypeAdapterFactory<T> of(Class<T> baseType, String typeFieldName) {
-        return new RuntimeTypeAdapterFactory<T>(baseType, typeFieldName, false);
+        return new RuntimeTypeAdapterFactory<>(baseType, typeFieldName, false);
     }
 
     /**
@@ -195,7 +179,7 @@ public final class RuntimeTypeAdapterFactory<T> implements TypeAdapterFactory {
      * field name.
      */
     public static <T> RuntimeTypeAdapterFactory<T> of(Class<T> baseType) {
-        return new RuntimeTypeAdapterFactory<T>(baseType, "type", false);
+        return new RuntimeTypeAdapterFactory<>(baseType, "type", false);
     }
 
     /**
@@ -216,26 +200,15 @@ public final class RuntimeTypeAdapterFactory<T> implements TypeAdapterFactory {
         return this;
     }
 
-    /**
-     * Registers {@code type} identified by its {@link Class#getSimpleName simple name}. Labels are
-     * case sensitive.
-     *
-     * @throws IllegalArgumentException if either {@code type} or its simple name have already been
-     *     registered on this type adapter.
-     */
-    public RuntimeTypeAdapterFactory<T> registerSubtype(Class<? extends T> type) {
-        return registerSubtype(type, type.getSimpleName());
-    }
-
     public <R> TypeAdapter<R> create(Gson gson, TypeToken<R> type) {
         if (type.getRawType() != baseType) {
             return null;
         }
 
         final Map<String, TypeAdapter<?>> labelToDelegate =
-                new LinkedHashMap<String, TypeAdapter<?>>(labelToSubtype.size());
+                new LinkedHashMap<>(labelToSubtype.size());
         final Map<Class<?>, TypeAdapter<?>> subtypeToDelegate =
-                new LinkedHashMap<Class<?>, TypeAdapter<?>>(labelToSubtype.size());
+                new LinkedHashMap<>(labelToSubtype.size());
         for (Map.Entry<String, Class<?>> entry : labelToSubtype.entrySet()) {
             TypeAdapter<?> delegate =
                     gson.getDelegateAdapter(this, TypeToken.get(entry.getValue()));
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/AutomationController.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/AutomationController.java
index 5f93b86..c3027ae 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/AutomationController.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/AutomationController.java
@@ -33,8 +33,7 @@ public class AutomationController {
     @GetMapping
     public List<Automation> getAll(
             @RequestParam(value = "hostId", required = false) Long hostId,
-            final Principal principal)
-            throws NotFoundException {
+            final Principal principal) {
         final Long userId = userService.findByUsername(principal.getName()).getId();
         return automationRepository.findAllByUserId(userId);
     }
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/DimmableLightController.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/DimmableLightController.java
index ffd39fa..990c105 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/DimmableLightController.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/DimmableLightController.java
@@ -49,10 +49,10 @@ public class DimmableLightController extends GuestEnabledController<DimmableLigh
         }
     }
 
-    /*
-       Assume that only the host can create a device
-       Here save always as host, but remember to propagate change to guests (DeviceService.saveAsOwner())
-    */
+    /**
+     * Assume that only the host can create a device Here save always as host, but remember to
+     * propagate change to guests (DeviceService.saveAsOwner())
+     */
     @PostMapping
     public DimmableLight create(
             @Valid @RequestBody DimmableSaveRequest dl, final Principal principal)
@@ -61,9 +61,7 @@ public class DimmableLightController extends GuestEnabledController<DimmableLigh
         return save(new DimmableLight(), dl, principal.getName(), null);
     }
 
-    /*
-      Logic for saving either as owner or guest is handled in method save of this controller
-    */
+    /** Logic for saving either as owner or guest is handled in method save of this controller */
     @PutMapping
     public DimmableLight update(
             @Valid @RequestBody DimmableSaveRequest sp,
@@ -84,8 +82,10 @@ public class DimmableLightController extends GuestEnabledController<DimmableLigh
         deviceService.deleteByIdAsOwner(id, principal.getName());
     }
 
-    // the full url should be: "/dimmableLight/{id}/state?sceneId={sceneId}
-    // however it is not necessary to specify the query in the mapping
+    /**
+     * the full url should be: "/dimmableLight/{id}/state?sceneId={sceneId} however it is not
+     * necessary to specify the query in the mapping
+     */
     @PostMapping("/{id}/state")
     public State<? extends Dimmable> sceneBinding(
             @PathVariable("id") long deviceId,
diff --git a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/GuestController.java b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/GuestController.java
index f010b52..4b7109d 100644
--- a/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/GuestController.java
+++ b/src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/GuestController.java
@@ -5,7 +5,6 @@ import static ch.usi.inf.sa4.sanmarinoes.smarthut.utils.Utils.toList;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.GuestPermissionsRequest;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.GuestsUpdateRequest;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.UserResponse;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.EagerUserRepository;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.User;
 import java.security.Principal;
@@ -46,8 +45,7 @@ public class GuestController {
 
     @PutMapping("/guests")
     public List<User> setGuests(
-            @RequestBody @Valid GuestsUpdateRequest g, final Principal principal)
-            throws NotFoundException {
+            @RequestBody @Valid GuestsUpdateRequest g, final Principal principal) {
         Iterable<User> guests = userRepository.findAllById(g.ids);
         User host = userRepository.findByUsername(principal.getName());