Fixes to Scene implementation

build.gradle

@@ -9,6 +9,7 @@ version = '0.0.1-SNAPSHOT'
 sourceCompatibility = '11'
 repositories {
 	mavenCentral()
+
 }
 dependencies {
 	compile 'org.hibernate.javax.persistence:hibernate-jpa-2.1-api:1.0.0.Final'
@@ -39,6 +40,13 @@ dependencies {
 	// Fixes https://stackoverflow.com/a/60455550
 	testImplementation group: 'org.apache.httpcomponents', name: 'httpclient', version: '4.5.11'
 }
+
+gradle.projectsEvaluated {
+	tasks.withType(JavaCompile) {
+		options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
+	}
+}
+
 test {
 	useJUnitPlatform()
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/GsonConfig.java

@@ -1,5 +1,8 @@
 package ch.usi.inf.sa4.sanmarinoes.smarthut.config;
 
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.DimmableState;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.State;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SwitchableState;
 import com.google.gson.*;
 import java.lang.reflect.Type;
 import org.springframework.context.annotation.Bean;
@@ -24,6 +27,11 @@ public class GsonConfig {
         final GsonBuilder builder = new GsonBuilder();
         builder.registerTypeAdapter(Json.class, new SpringfoxJsonToGsonAdapter());
         builder.addSerializationExclusionStrategy(new AnnotationExclusionStrategy());
+        RuntimeTypeAdapterFactory<State> runtimeTypeAdapterFactory =
+                RuntimeTypeAdapterFactory.of(State.class, "kind")
+                        .registerSubtype(SwitchableState.class, "switchableState")
+                        .registerSubtype(DimmableState.class, "dimmableState");
+        builder.registerTypeAdapterFactory(runtimeTypeAdapterFactory);
         return builder.create();
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/config/RuntimeTypeAdapterFactory.java

@@ -0,0 +1,315 @@
+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;
+import com.google.gson.JsonParseException;
+import com.google.gson.JsonPrimitive;
+import com.google.gson.TypeAdapter;
+import com.google.gson.TypeAdapterFactory;
+import com.google.gson.internal.Streams;
+import com.google.gson.reflect.TypeToken;
+import com.google.gson.stream.JsonReader;
+import com.google.gson.stream.JsonWriter;
+import java.io.IOException;
+import java.util.LinkedHashMap;
+import java.util.Map;
+
+/**
+ * Adapts values whose runtime type may differ from their declaration type. This is necessary when a
+ * field's type is not the same type that GSON should create when deserializing that field. For
+ * example, consider these types:
+ *
+ * <pre>{@code
+ * abstract class Shape {
+ *   int x;
+ *   int y;
+ * }
+ * class Circle extends Shape {
+ *   int radius;
+ * }
+ * class Rectangle extends Shape {
+ *   int width;
+ *   int height;
+ * }
+ * class Diamond extends Shape {
+ *   int width;
+ *   int height;
+ * }
+ * class Drawing {
+ *   Shape bottomShape;
+ *   Shape topShape;
+ * }
+ * }</pre>
+ *
+ * <p>Without additional type information, the serialized JSON is ambiguous. Is the bottom shape in
+ * this drawing a rectangle or a diamond?
+ *
+ * <pre>{@code
+ * {
+ *   "bottomShape": {
+ *     "width": 10,
+ *     "height": 5,
+ *     "x": 0,
+ *     "y": 0
+ *   },
+ *   "topShape": {
+ *     "radius": 2,
+ *     "x": 4,
+ *     "y": 1
+ *   }
+ * }
+ * }</pre>
+ *
+ * This class addresses this problem by adding type information to the serialized JSON and honoring
+ * that type information when the JSON is deserialized:
+ *
+ * <pre>{@code
+ * {
+ *   "bottomShape": {
+ *     "type": "Diamond",
+ *     "width": 10,
+ *     "height": 5,
+ *     "x": 0,
+ *     "y": 0
+ *   },
+ *   "topShape": {
+ *     "type": "Circle",
+ *     "radius": 2,
+ *     "x": 4,
+ *     "y": 1
+ *   }
+ * }
+ * }</pre>
+ *
+ * Both the type field name ({@code "type"}) and the type labels ({@code "Rectangle"}) are
+ * configurable.
+ *
+ * <h3>Registering Types</h3>
+ *
+ * Create a {@code RuntimeTypeAdapterFactory} by passing the base type and type field name to the
+ * {@link #of} factory method. If you don't supply an explicit type field name, {@code "type"} will
+ * be used.
+ *
+ * <pre>{@code
+ * RuntimeTypeAdapterFactory<Shape> shapeAdapterFactory
+ *     = RuntimeTypeAdapterFactory.of(Shape.class, "type");
+ * }</pre>
+ *
+ * Next register all of your subtypes. Every subtype must be explicitly registered. This protects
+ * your application from injection attacks. If you don't supply an explicit type label, the type's
+ * simple name will be used.
+ *
+ * <pre>{@code
+ * shapeAdapterFactory.registerSubtype(Rectangle.class, "Rectangle");
+ * shapeAdapterFactory.registerSubtype(Circle.class, "Circle");
+ * shapeAdapterFactory.registerSubtype(Diamond.class, "Diamond");
+ * }</pre>
+ *
+ * Finally, register the type adapter factory in your application's GSON builder:
+ *
+ * <pre>{@code
+ * Gson gson = new GsonBuilder()
+ *     .registerTypeAdapterFactory(shapeAdapterFactory)
+ *     .create();
+ * }</pre>
+ *
+ * Like {@code GsonBuilder}, this API supports chaining:
+ *
+ * <pre>{@code
+ * RuntimeTypeAdapterFactory<Shape> shapeAdapterFactory = RuntimeTypeAdapterFactory.of(Shape.class)
+ *     .registerSubtype(Rectangle.class)
+ *     .registerSubtype(Circle.class)
+ *     .registerSubtype(Diamond.class);
+ * }</pre>
+ *
+ * <h3>Serialization and deserialization</h3>
+ *
+ * In order to serialize and deserialize a polymorphic object, you must specify the base type
+ * explicitly.
+ *
+ * <pre>{@code
+ * Diamond diamond = new Diamond();
+ * String json = gson.toJson(diamond, Shape.class);
+ * }</pre>
+ *
+ * And then:
+ *
+ * <pre>{@code
+ * Shape shape = gson.fromJson(json, Shape.class);
+ * }</pre>
+ */
+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 boolean maintainType;
+
+    private RuntimeTypeAdapterFactory(
+            Class<?> baseType, String typeFieldName, boolean maintainType) {
+        if (typeFieldName == null || baseType == null) {
+            throw new NullPointerException();
+        }
+        this.baseType = baseType;
+        this.typeFieldName = typeFieldName;
+        this.maintainType = maintainType;
+    }
+
+    /**
+     * Creates a new runtime type adapter using for {@code baseType} using {@code typeFieldName} as
+     * the type field name. Type field names are case sensitive. {@code maintainType} flag decide if
+     * the type will be stored in pojo or not.
+     */
+    public static <T> RuntimeTypeAdapterFactory<T> of(
+            Class<T> baseType, String typeFieldName, boolean maintainType) {
+        return new RuntimeTypeAdapterFactory<T>(baseType, typeFieldName, maintainType);
+    }
+
+    /**
+     * Creates a new runtime type adapter using for {@code baseType} using {@code typeFieldName} as
+     * 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);
+    }
+
+    /**
+     * Creates a new runtime type adapter for {@code baseType} using {@code "type"} as the type
+     * field name.
+     */
+    public static <T> RuntimeTypeAdapterFactory<T> of(Class<T> baseType) {
+        return new RuntimeTypeAdapterFactory<T>(baseType, "type", false);
+    }
+
+    /**
+     * Registers {@code type} identified by {@code label}. Labels are case sensitive.
+     *
+     * @throws IllegalArgumentException if either {@code type} or {@code label} have already been
+     *     registered on this type adapter.
+     */
+    public RuntimeTypeAdapterFactory<T> registerSubtype(Class<? extends T> type, String label) {
+        if (type == null || label == null) {
+            throw new NullPointerException();
+        }
+        if (subtypeToLabel.containsKey(type) || labelToSubtype.containsKey(label)) {
+            throw new IllegalArgumentException("types and labels must be unique");
+        }
+        labelToSubtype.put(label, type);
+        subtypeToLabel.put(type, label);
+        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<?>>();
+        final Map<Class<?>, TypeAdapter<?>> subtypeToDelegate =
+                new LinkedHashMap<Class<?>, TypeAdapter<?>>();
+        for (Map.Entry<String, Class<?>> entry : labelToSubtype.entrySet()) {
+            TypeAdapter<?> delegate =
+                    gson.getDelegateAdapter(this, TypeToken.get(entry.getValue()));
+            labelToDelegate.put(entry.getKey(), delegate);
+            subtypeToDelegate.put(entry.getValue(), delegate);
+        }
+
+        return new TypeAdapter<R>() {
+            @Override
+            public R read(JsonReader in) throws IOException {
+                JsonElement jsonElement = Streams.parse(in);
+                JsonElement labelJsonElement;
+                if (maintainType) {
+                    labelJsonElement = jsonElement.getAsJsonObject().get(typeFieldName);
+                } else {
+                    labelJsonElement = jsonElement.getAsJsonObject().remove(typeFieldName);
+                }
+
+                if (labelJsonElement == null) {
+                    throw new JsonParseException(
+                            "cannot deserialize "
+                                    + baseType
+                                    + " because it does not define a field named "
+                                    + typeFieldName);
+                }
+                String label = labelJsonElement.getAsString();
+                @SuppressWarnings("unchecked") // registration requires that subtype extends T
+                TypeAdapter<R> delegate = (TypeAdapter<R>) labelToDelegate.get(label);
+                if (delegate == null) {
+                    throw new JsonParseException(
+                            "cannot deserialize "
+                                    + baseType
+                                    + " subtype named "
+                                    + label
+                                    + "; did you forget to register a subtype?");
+                }
+                return delegate.fromJsonTree(jsonElement);
+            }
+
+            @Override
+            public void write(JsonWriter out, R value) throws IOException {
+                Class<?> srcType = value.getClass();
+                String label = subtypeToLabel.get(srcType);
+                @SuppressWarnings("unchecked") // registration requires that subtype extends T
+                TypeAdapter<R> delegate = (TypeAdapter<R>) subtypeToDelegate.get(srcType);
+                if (delegate == null) {
+                    throw new JsonParseException(
+                            "cannot serialize "
+                                    + srcType.getName()
+                                    + "; did you forget to register a subtype?");
+                }
+                JsonObject jsonObject = delegate.toJsonTree(value).getAsJsonObject();
+
+                if (maintainType) {
+                    Streams.write(jsonObject, out);
+                    return;
+                }
+
+                JsonObject clone = new JsonObject();
+
+                if (jsonObject.has(typeFieldName)) {
+                    throw new JsonParseException(
+                            "cannot serialize "
+                                    + srcType.getName()
+                                    + " because it already defines a field named "
+                                    + typeFieldName);
+                }
+                clone.add(typeFieldName, new JsonPrimitive(label));
+
+                for (Map.Entry<String, JsonElement> e : jsonObject.entrySet()) {
+                    clone.add(e.getKey(), e.getValue());
+                }
+                Streams.write(clone, out);
+            }
+        }.nullSafe();
+    }
+}

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/CurtainsController.java

@@ -3,13 +3,9 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.controller;
 import static ch.usi.inf.sa4.sanmarinoes.smarthut.utils.Utils.toList;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.DimmableSaveRequest;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.error.DuplicateStateException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.Curtains;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.CurtainsRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.Dimmable;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.DimmableState;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SceneRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.StateRepository;
 import java.security.Principal;
 import java.util.List;
 import javax.validation.Valid;
@@ -23,7 +19,7 @@ import org.springframework.web.bind.annotation.*;
 public class CurtainsController {
     @Autowired private CurtainsRepository curtainsService;
     @Autowired private SceneRepository sceneRepository;
-    @Autowired private StateRepository stateRepository;
+    @Autowired private StateRepository<State<?>> stateRepository;
 
     @GetMapping
     public List<Curtains> findAll() {
@@ -62,19 +58,21 @@ public class CurtainsController {
     }
 
     @PostMapping("/{id}/state")
-    public void sceneBinding(
+    public State<? extends Dimmable> sceneBinding(
             @PathVariable("id") long deviceId,
             @RequestParam long sceneId,
             final Principal principal)
-            throws NotFoundException {
+            throws NotFoundException, DuplicateStateException {
 
         Curtains c =
                 curtainsService
                         .findByIdAndUsername(deviceId, principal.getName())
                         .orElseThrow(NotFoundException::new);
-        DimmableState<Dimmable> s = c.cloneState();
+        State<? extends Dimmable> s = c.cloneState();
         sceneRepository.findById(sceneId).orElseThrow(NotFoundException::new);
         s.setSceneId(sceneId);
-        stateRepository.save(s);
+        if (stateRepository.countByDeviceIdAndSceneId(deviceId, sceneId) > 0)
+            throw new DuplicateStateException();
+        return stateRepository.save(s);
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/DimmableLightController.java

@@ -3,13 +3,9 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.controller;
 import static ch.usi.inf.sa4.sanmarinoes.smarthut.utils.Utils.toList;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.DimmableSaveRequest;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.error.DuplicateStateException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.Dimmable;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.DimmableLight;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.DimmableLightRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SceneRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.State;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.StateRepository;
 import java.security.Principal;
 import java.util.List;
 import javax.validation.Valid;
@@ -24,7 +20,7 @@ public class DimmableLightController {
 
     @Autowired private DimmableLightRepository dimmableLightService;
     @Autowired private SceneRepository sceneRepository;
-    @Autowired private StateRepository stateRepository;
+    @Autowired private StateRepository<State<?>> stateRepository;
 
     @GetMapping
     public List<DimmableLight> findAll() {
@@ -68,19 +64,21 @@ public class DimmableLightController {
     // 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 void sceneBinding(
+    public State<? extends Dimmable> sceneBinding(
             @PathVariable("id") long deviceId,
             @RequestParam long sceneId,
             final Principal principal)
-            throws NotFoundException {
+            throws NotFoundException, DuplicateStateException {
 
         DimmableLight d =
                 dimmableLightService
                         .findByIdAndUsername(deviceId, principal.getName())
                         .orElseThrow(NotFoundException::new);
-        State<Dimmable> s = d.cloneState();
+        State<? extends Dimmable> s = d.cloneState();
         sceneRepository.findById(sceneId).orElseThrow(NotFoundException::new);
         s.setSceneId(sceneId);
-        stateRepository.save(s);
+        if (stateRepository.countByDeviceIdAndSceneId(deviceId, sceneId) > 0)
+            throw new DuplicateStateException();
+        return stateRepository.save(s);
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/RegularLightController.java

@@ -3,13 +3,9 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.controller;
 import static ch.usi.inf.sa4.sanmarinoes.smarthut.utils.Utils.toList;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.SwitchableSaveRequest;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.error.DuplicateStateException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.OutputDevice;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.RegularLight;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.RegularLightRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SceneRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.State;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.StateRepository;
 import java.security.Principal;
 import java.util.List;
 import javax.validation.Valid;
@@ -32,7 +28,7 @@ public class RegularLightController {
 
     @Autowired private RegularLightRepository regularLightService;
     @Autowired private SceneRepository sceneRepository;
-    @Autowired private StateRepository stateRepository;
+    @Autowired private StateRepository<State<?>> stateRepository;
 
     @GetMapping
     public List<RegularLight> findAll() {
@@ -76,18 +72,20 @@ public class RegularLightController {
     // 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 void sceneBinding(
+    public State<? extends Switchable> sceneBinding(
             @PathVariable("id") long deviceId,
             @RequestParam long sceneId,
             final Principal principal)
-            throws NotFoundException {
+            throws NotFoundException, DuplicateStateException {
         RegularLight d =
                 regularLightService
                         .findByIdAndUsername(deviceId, principal.getName())
                         .orElseThrow(NotFoundException::new);
-        State<? extends OutputDevice> s = d.cloneState();
+        State<? extends Switchable> s = d.cloneState();
         sceneRepository.findById(sceneId).orElseThrow(NotFoundException::new);
         s.setSceneId(sceneId);
-        stateRepository.save(s);
+        if (stateRepository.countByDeviceIdAndSceneId(deviceId, sceneId) > 0)
+            throw new DuplicateStateException();
+        return stateRepository.save(s);
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/SecurityCameraController.java

@@ -3,13 +3,9 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.controller;
 import static ch.usi.inf.sa4.sanmarinoes.smarthut.utils.Utils.toList;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.SwitchableSaveRequest;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.error.DuplicateStateException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.OutputDevice;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SceneRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SecurityCamera;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.SecurityCameraRepository;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.State;
-import ch.usi.inf.sa4.sanmarinoes.smarthut.models.StateRepository;
 import java.security.Principal;
 import java.util.List;
 import javax.validation.Valid;
@@ -32,7 +28,7 @@ public class SecurityCameraController {
 
     @Autowired SecurityCameraRepository securityCameraService;
     @Autowired private SceneRepository sceneRepository;
-    @Autowired private StateRepository stateRepository;
+    @Autowired private StateRepository<State<?>> stateRepository;
 
     @GetMapping
     public List<SecurityCamera> findAll() {
@@ -74,19 +70,21 @@ public class SecurityCameraController {
     }
 
     @PostMapping("/{id}/state")
-    public void sceneBinding(
+    public State<? extends Switchable> sceneBinding(
             @PathVariable("id") long deviceId,
             @RequestParam long sceneId,
             final Principal principal)
-            throws NotFoundException {
+            throws NotFoundException, DuplicateStateException {
 
         SecurityCamera d =
                 securityCameraService
                         .findByIdAndUsername(deviceId, principal.getName())
                         .orElseThrow(NotFoundException::new);
-        State<? extends OutputDevice> s = d.cloneState();
+        State<? extends Switchable> s = d.cloneState();
         sceneRepository.findById(sceneId).orElseThrow(NotFoundException::new);
         s.setSceneId(sceneId);
-        stateRepository.save(s);
+        if (stateRepository.countByDeviceIdAndSceneId(deviceId, sceneId) > 0)
+            throw new DuplicateStateException();
+        return stateRepository.save(s);
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/SmartPlugController.java

@@ -3,6 +3,7 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.controller;
 import static ch.usi.inf.sa4.sanmarinoes.smarthut.utils.Utils.toList;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.SwitchableSaveRequest;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.error.DuplicateStateException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
 import java.security.Principal;
@@ -19,7 +20,7 @@ public class SmartPlugController {
 
     @Autowired private SmartPlugRepository smartPlugRepository;
     @Autowired private SceneRepository sceneRepository;
-    @Autowired private StateRepository stateRepository;
+    @Autowired private StateRepository<State<?>> stateRepository;
 
     @GetMapping
     public List<SmartPlug> findAll() {
@@ -73,19 +74,21 @@ public class SmartPlugController {
     }
 
     @PostMapping("/{id}/state")
-    public void sceneBinding(
+    public State<? extends Switchable> sceneBinding(
             @PathVariable("id") long deviceId,
             @RequestParam long sceneId,
             final Principal principal)
-            throws NotFoundException {
+            throws NotFoundException, DuplicateStateException {
 
         SmartPlug d =
                 smartPlugRepository
                         .findByIdAndUsername(deviceId, principal.getName())
                         .orElseThrow(NotFoundException::new);
-        State<? extends OutputDevice> s = d.cloneState();
+        State<? extends Switchable> s = d.cloneState();
         sceneRepository.findById(sceneId).orElseThrow(NotFoundException::new);
         s.setSceneId(sceneId);
-        stateRepository.save(s);
+        if (stateRepository.countByDeviceIdAndSceneId(deviceId, sceneId) > 0)
+            throw new DuplicateStateException();
+        return stateRepository.save(s);
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/controller/ThermostatController.java

@@ -1,6 +1,7 @@
 package ch.usi.inf.sa4.sanmarinoes.smarthut.controller;
 
 import ch.usi.inf.sa4.sanmarinoes.smarthut.dto.ThermostatSaveRequest;
+import ch.usi.inf.sa4.sanmarinoes.smarthut.error.DuplicateStateException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.error.NotFoundException;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.models.*;
 import ch.usi.inf.sa4.sanmarinoes.smarthut.service.ThermostatService;
@@ -21,7 +22,7 @@ public class ThermostatController {
     @Autowired private ThermostatService thermostatService;
 
     @Autowired private SceneRepository sceneRepository;
-    @Autowired private StateRepository stateRepository;
+    @Autowired private StateRepository<State<?>> stateRepository;
 
     @GetMapping
     public List<Thermostat> findAll(Principal user) {
@@ -70,19 +71,21 @@ public class ThermostatController {
     }
 
     @PostMapping("/{id}/state")
-    public void sceneBinding(
+    public State<? extends Switchable> sceneBinding(
             @PathVariable("id") long deviceId,
             @RequestParam long sceneId,
             final Principal principal)
-            throws NotFoundException {
+            throws NotFoundException, DuplicateStateException {
 
         Thermostat d =
                 thermostatRepository
                         .findByIdAndUsername(deviceId, principal.getName())
                         .orElseThrow(NotFoundException::new);
-        State<? extends OutputDevice> s = d.cloneState();
+        State<? extends Switchable> s = d.cloneState();
         sceneRepository.findById(sceneId).orElseThrow(NotFoundException::new);
         s.setSceneId(sceneId);
-        stateRepository.save(s);
+        if (stateRepository.countByDeviceIdAndSceneId(deviceId, sceneId) > 0)
+            throw new DuplicateStateException();
+        return stateRepository.save(s);
     }
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/error/DuplicateStateException.java

@@ -0,0 +1,12 @@
+package ch.usi.inf.sa4.sanmarinoes.smarthut.error;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+@ResponseStatus(code = HttpStatus.BAD_REQUEST)
+public class DuplicateStateException extends Exception {
+    public DuplicateStateException() {
+        super(
+                "Cannot create state since it has already been created for this scene and this device");
+    }
+}

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Dimmable.java

@@ -78,7 +78,7 @@ public class Dimmable extends Switchable {
     }
 
     @Override
-    public DimmableState<Dimmable> cloneState() {
+    public State<? extends Dimmable> cloneState() {
         final DimmableState<Dimmable> newState = new DimmableState<>();
         newState.setDeviceId(getId());
         newState.setDevice(this);

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/DimmableState.java

@@ -1,28 +1,24 @@
 package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 
-import javax.persistence.Column;
 import javax.persistence.Entity;
 import javax.validation.constraints.Max;
 import javax.validation.constraints.Min;
-import javax.validation.constraints.NotNull;
 
 /** Represent a state for an IDimmable device */
 @Entity
 public class DimmableState<T extends Dimmable> extends State<T> {
 
     /** The light intensity value. Goes from 0 (off) to 100 (on) */
-    @NotNull
-    @Column(nullable = false)
     @Min(0)
     @Max(100)
-    private Integer dimAmount = 0;
+    private int intensity = 0;
 
-    public Integer getIntensity() {
+    public int getIntensity() {
-        return dimAmount;
+        return intensity;
     }
 
-    public void setIntensity(Integer dimAmount) {
+    public void setIntensity(int dimAmount) {
-        this.dimAmount = dimAmount;
+        this.intensity = dimAmount;
     }
 
     @Override

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Room.java

@@ -145,6 +145,7 @@ public class Room {
      */
     @NotNull
     @Column(name = "user_id", nullable = false)
+    @GsonExclude
     private Long userId;
 
     /** The user given name of this room (e.g. 'Master bedroom') */

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Scene.java

@@ -31,6 +31,7 @@ public class Scene {
 
     @NotNull
     @Column(name = "user_id", nullable = false)
+    @GsonExclude
     private Long userId;
 
     /** The user given name of this room (e.g. 'Master bedroom') */

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/State.java

@@ -10,6 +10,7 @@ import javax.validation.constraints.NotNull;
  * other properties) form a Scene
  */
 @Entity
+@Table(uniqueConstraints = {@UniqueConstraint(columnNames = {"device_id", "scene_id"})})
 @Inheritance(strategy = InheritanceType.SINGLE_TABLE)
 public abstract class State<D extends OutputDevice> {
 

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/StateRepository.java

@@ -11,4 +11,6 @@ public interface StateRepository<T extends State<?>> extends CrudRepository<T, L
     void deleteAllBySceneId(long roomId);
 
     List<T> findBySceneId(@Param("sceneId") long sceneId);
+
+    Integer countByDeviceIdAndSceneId(long deviceId, long sceneId);
 }

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/Switchable.java

@@ -44,7 +44,7 @@ public abstract class Switchable extends OutputDevice {
     }
 
     @Override
-    public State<? extends OutputDevice> cloneState() {
+    public State<? extends Switchable> cloneState() {
         final SwitchableState<Switchable> newState = new SwitchableState<>();
         newState.setDeviceId(getId());
         newState.setDevice(this);

src/main/java/ch/usi/inf/sa4/sanmarinoes/smarthut/models/SwitchableState.java

@@ -2,14 +2,12 @@ package ch.usi.inf.sa4.sanmarinoes.smarthut.models;
 
 import javax.persistence.Column;
 import javax.persistence.Entity;
-import javax.validation.constraints.NotNull;
 
 /** Represents a state for a Switchable device */
 @Entity
 public class SwitchableState<T extends Switchable> extends State<T> {
 
-    @Column(name = "switchable_on", nullable = false)
+    @Column(name = "switchable_on")
-    @NotNull
     private boolean on;
 
     public boolean isOn() {