[hue] Handle unexpected empty response from API (#14297)

Fix #14218

Signed-off-by: Laurent Garnier <lg.hc@free.fr>

bundles/org.openhab.binding.hue/src/main/java/org/openhab/binding/hue/internal/connection/HueBridge.java

@@ -72,6 +72,7 @@ import org.openhab.binding.hue.internal.dto.SuccessResponse;
 import org.openhab.binding.hue.internal.dto.Util;
 import org.openhab.binding.hue.internal.exceptions.ApiException;
 import org.openhab.binding.hue.internal.exceptions.DeviceOffException;
+import org.openhab.binding.hue.internal.exceptions.EmptyResponseException;
 import org.openhab.binding.hue.internal.exceptions.EntityNotAvailableException;
 import org.openhab.binding.hue.internal.exceptions.GroupTableFullException;
 import org.openhab.binding.hue.internal.exceptions.InvalidCommandException;
@@ -252,6 +253,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'lights' returned an unexpected empty reponse");
+        }
+
         Map<String, T> lightMap = safeFromJson(result.body, gsonType);
         List<T> lights = new ArrayList<>();
         lightMap.forEach((id, light) -> {
@@ -275,6 +280,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'sensors' returned an unexpected empty reponse");
+        }
+
         Map<String, FullSensor> sensorMap = safeFromJson(result.body, FullSensor.GSON_TYPE);
         List<FullSensor> sensors = new ArrayList<>();
         sensorMap.forEach((id, sensor) -> {
@@ -300,6 +309,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'lights/new' returned an unexpected empty reponse");
+        }
+
         String lastScan = safeFromJson(result.body, NewLightsResponse.class).lastscan;
 
         switch (lastScan) {
@@ -362,6 +375,11 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException(
+                    "GET request 'lights/" + enc(light.getId()) + "' returned an unexpected empty reponse");
+        }
+
         FullHueObject fullLight = safeFromJson(result.body, FullLight.class);
         fullLight.setId(light.getId());
         return fullLight;
@@ -386,6 +404,11 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException(
+                    "PUT request 'lights/" + enc(light.getId()) + "' returned an unexpected empty reponse");
+        }
+
         List<SuccessResponse> entries = safeFromJson(result.body, SuccessResponse.GSON_TYPE);
         SuccessResponse response = entries.get(0);
 
@@ -469,6 +492,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'groups' returned an unexpected empty reponse");
+        }
+
         Map<String, FullGroup> groupMap = safeFromJson(result.body, FullGroup.GSON_TYPE);
         List<FullGroup> groups = new ArrayList<>();
         if (groupMap.get("0") == null) {
@@ -510,6 +537,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("POST request 'groups' returned an unexpected empty reponse");
+        }
+
         List<SuccessResponse> entries = safeFromJson(result.body, SuccessResponse.GSON_TYPE);
         SuccessResponse response = entries.get(0);
 
@@ -540,6 +571,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("POST request 'groups' returned an unexpected empty reponse");
+        }
+
         List<SuccessResponse> entries = safeFromJson(result.body, SuccessResponse.GSON_TYPE);
         SuccessResponse response = entries.get(0);
 
@@ -565,6 +600,11 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException(
+                    "GET request 'groups/" + enc(group.getId()) + "' returned an unexpected empty reponse");
+        }
+
         FullGroup fullGroup = safeFromJson(result.body, FullGroup.class);
         fullGroup.setId(group.getId());
         return fullGroup;
@@ -593,6 +633,11 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException(
+                    "PUT request 'groups/" + enc(group.getId()) + "' returned an unexpected empty reponse");
+        }
+
         List<SuccessResponse> entries = safeFromJson(result.body, SuccessResponse.GSON_TYPE);
         SuccessResponse response = entries.get(0);
 
@@ -648,6 +693,11 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException(
+                    "PUT request 'groups/" + enc(group.getId()) + "' returned an unexpected empty reponse");
+        }
+
         List<SuccessResponse> entries = safeFromJson(result.body, SuccessResponse.GSON_TYPE);
         SuccessResponse response = entries.get(0);
 
@@ -707,6 +757,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'schedules' returned an unexpected empty reponse");
+        }
+
         Map<String, Schedule> scheduleMap = safeFromJson(result.body, Schedule.GSON_TYPE);
         List<Schedule> schedules = new ArrayList<>();
         scheduleMap.forEach((id, schedule) -> {
@@ -761,6 +815,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'scenes' returned an unexpected empty reponse");
+        }
+
         Map<String, Scene> sceneMap = safeFromJson(result.body, Scene.GSON_TYPE);
         return sceneMap.entrySet().stream()//
                 .map(e -> {
@@ -841,6 +899,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("POST request (link) returned an unexpected empty reponse");
+        }
+
         List<SuccessResponse> entries = safeFromJson(result.body, SuccessResponse.GSON_TYPE);
         SuccessResponse response = entries.get(0);
 
@@ -865,6 +927,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request 'config' returned an unexpected empty reponse");
+        }
+
         return safeFromJson(result.body, Config.class);
     }
 
@@ -912,6 +978,10 @@ public class HueBridge {
 
         handleErrors(result);
 
+        if (result.body.isBlank()) {
+            throw new EmptyResponseException("GET request (getFullConfig) returned an unexpected empty reponse");
+        }
+
         FullConfig fullConfig = gson.fromJson(result.body, FullConfig.class);
         return Objects.requireNonNull(fullConfig);
     }

bundles/org.openhab.binding.hue/src/main/java/org/openhab/binding/hue/internal/exceptions/EmptyResponseException.java

@@ -0,0 +1,31 @@
+/**
+ * Copyright (c) 2010-2023 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.binding.hue.internal.exceptions;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
+/**
+ * Thrown when API is returning an unexpected empty response.
+ *
+ * @author Laurent Garnier - Initial contribution
+ */
+@SuppressWarnings("serial")
+@NonNullByDefault
+public class EmptyResponseException extends ApiException {
+    public EmptyResponseException() {
+    }
+
+    public EmptyResponseException(String message) {
+        super(message);
+    }
+}

bundles/org.openhab.binding.hue/src/main/java/org/openhab/binding/hue/internal/handler/HueBridgeHandler.java

@@ -49,6 +49,7 @@ import org.openhab.binding.hue.internal.dto.State;
 import org.openhab.binding.hue.internal.dto.StateUpdate;
 import org.openhab.binding.hue.internal.exceptions.ApiException;
 import org.openhab.binding.hue.internal.exceptions.DeviceOffException;
+import org.openhab.binding.hue.internal.exceptions.EmptyResponseException;
 import org.openhab.binding.hue.internal.exceptions.EntityNotAvailableException;
 import org.openhab.binding.hue.internal.exceptions.LinkButtonException;
 import org.openhab.binding.hue.internal.exceptions.UnauthorizedException;
@@ -150,6 +151,9 @@ public class HueBridgeHandler extends ConfigStatusBridgeHandler implements HueCl
                     lastBridgeConnectionState = false;
                     onConnectionLost();
                 }
+            } catch (EmptyResponseException e) {
+                // Unexpected empty response is ignored
+                logger.debug("{}", e.getMessage());
             } catch (ApiException | CommunicationException | IOException e) {
                 if (hueBridge != null && lastBridgeConnectionState) {
                     logger.debug("Connection to Hue Bridge {} lost: {}", hueBridge.getIPAddress(), e.getMessage(), e);