[evohome] Add null annotation and minor refactoring (#13885)

Signed-off-by: Leo Siepel <leosiepel@gmail.com>

bundles/org.openhab.binding.evohome/README.md

@@ -64,11 +64,12 @@ None
 
 ### Zone
 
-| Channel Type ID   | Item Type | Description                                                                                                                                                                                                            |
+| Channel Type ID | Item Type          | Description                                                                                                                            |
-|-------------------|-----------|------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+|-----------------|--------------------|----------------------------------------------------------------------------------------------------------------------------------------|
-| Temperature       | Number    | Allows for viewing the current actual temperature of the zone.                                                                                                                                                     |
+| Temperature     | Number:Temperature | Allows for viewing the current actual temperature of the zone.                                                                         |
-| SetPointStatus    | String    | Allows for viewing the current set point mode of the zone.                                                                                                                                                      |
+| SetPointStatus  | String             | Allows for viewing the current set point mode of the zone.                                                                             |
-| SetPoint          | Number    | Allows for viewing and permanently overriding the temperature set point of the zone. Sending 0 cancels any active set point overrides.                                                                                                                                         |
+| SetPoint        | Number:Temperature | Allows for viewing and permanently overriding the temperature set point of the zone. Sending 0 cancels any active set point overrides. |
+                                                                                                                                 |
 
 ## Full Example
 
@@ -89,9 +90,9 @@ Bridge evohome:account:your_account_alias [ username="your_user_name", password=
 String DemoMode                 { channel="evohome:display:your_account_alias:your_display_alias:SystemMode" }
 
 // evohome Heatingzone
-Number DemoZoneTemperature    { channel="evohome:heatingzone:your_account_alias:your_zone_alias:Temperature" }
+Number:Temperature DemoZoneTemperature  { channel="evohome:heatingzone:your_account_alias:your_zone_alias:Temperature" }
-String DemoZoneSetPointStatus { channel="evohome:heatingzone:your_account_alias:your_zone_alias:SetPointStatus" }
+String DemoZoneSetPointStatus           { channel="evohome:heatingzone:your_account_alias:your_zone_alias:SetPointStatus" }
-Number DemoZoneSetPoint       { channel="evohome:heatingzone:your_account_alias:your_zone_alias:SetPoint" }
+Number:Temperature DemoZoneSetPoint     { channel="evohome:heatingzone:your_account_alias:your_zone_alias:SetPoint" }
 ```
 
 ### demo.sitemap

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/EvohomeBindingConstants.java

@@ -17,6 +17,7 @@ import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.thing.ThingTypeUID;
 
 /**
@@ -26,6 +27,7 @@ import org.openhab.core.thing.ThingTypeUID;
  * @author Jasper van Zuijlen - Initial contribution
  * @author Neil Renaud - Heating Zones
  */
+@NonNullByDefault
 public class EvohomeBindingConstants {
 
     private static final String BINDING_ID = "evohome";

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/RunnableWithTimeout.java

@@ -14,12 +14,15 @@ package org.openhab.binding.evohome.internal;
 
 import java.util.concurrent.TimeoutException;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
 /**
  * Provides an interface for a delegate that can throw a timeout
  *
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public interface RunnableWithTimeout {
 
     public abstract void run() throws TimeoutException;

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/ApiAccess.java

@@ -18,13 +18,15 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jetty.client.HttpClient;
 import org.eclipse.jetty.client.api.ContentResponse;
 import org.eclipse.jetty.client.api.Request;
 import org.eclipse.jetty.client.util.StringContentProvider;
 import org.eclipse.jetty.http.HttpMethod;
 import org.eclipse.jetty.http.HttpStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Authentication;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Authentication;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -37,17 +39,17 @@ import com.google.gson.GsonBuilder;
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class ApiAccess {
     private static final int REQUEST_TIMEOUT_SECONDS = 5;
     private final Logger logger = LoggerFactory.getLogger(ApiAccess.class);
     private final HttpClient httpClient;
-    private final Gson gson;
+    private final Gson gson = new GsonBuilder().create();
 
-    private Authentication authenticationData;
+    private @Nullable Authentication authenticationData;
-    private String applicationId;
+    private @Nullable String applicationId;
 
     public ApiAccess(HttpClient httpClient) {
-        this.gson = new GsonBuilder().create();
         this.httpClient = httpClient;
     }
 
@@ -56,7 +58,7 @@ public class ApiAccess {
      *
      * @param authentication The authentication details to apply
      */
-    public void setAuthentication(Authentication authentication) {
+    public void setAuthentication(@Nullable Authentication authentication) {
         authenticationData = authentication;
     }
 
@@ -65,7 +67,7 @@ public class ApiAccess {
      *
      * @return The current authentication details
      */
-    public Authentication getAuthentication() {
+    public @Nullable Authentication getAuthentication() {
         return authenticationData;
     }
 
@@ -74,7 +76,7 @@ public class ApiAccess {
      *
      * @param applicationId The application id to apply
      */
-    public void setApplicationId(String applicationId) {
+    public void setApplicationId(@Nullable String applicationId) {
         this.applicationId = applicationId;
     }
 
@@ -89,18 +91,16 @@ public class ApiAccess {
      * @return The result of the request or null
      * @throws TimeoutException Thrown when a request times out
      */
-    public <TOut> TOut doRequest(HttpMethod method, String url, Map<String, String> headers, String requestData,
+    public @Nullable <TOut> TOut doRequest(HttpMethod method, String url, Map<String, String> headers,
-            String contentType, Class<TOut> outClass) throws TimeoutException {
+            @Nullable String requestData, String contentType, @Nullable Class<TOut> outClass) throws TimeoutException {
-        TOut retVal = null;
         logger.debug("Requesting: [{}]", url);
-
+        @Nullable
+        TOut retVal = null;
         try {
             Request request = httpClient.newRequest(url).method(method);
 
-            if (headers != null) {
+            for (Map.Entry<String, String> header : headers.entrySet()) {
-                for (Map.Entry<String, String> header : headers.entrySet()) {
+                request.header(header.getKey(), header.getValue());
-                    request.header(header.getKey(), header.getValue());
-                }
             }
 
             if (requestData != null) {
@@ -109,8 +109,8 @@ public class ApiAccess {
 
             ContentResponse response = request.timeout(REQUEST_TIMEOUT_SECONDS, TimeUnit.SECONDS).send();
 
-            logger.debug("Response: {}", response);
+            logger.trace("Response: {}", response);
-            logger.debug("\n{}\n{}", response.getHeaders(), response.getContentAsString());
+            logger.trace("\n{}\n{}", response.getHeaders(), response.getContentAsString());
 
             if ((response.getStatus() == HttpStatus.OK_200) || (response.getStatus() == HttpStatus.ACCEPTED_202)) {
                 String reply = response.getContentAsString();
@@ -118,6 +118,10 @@ public class ApiAccess {
                 if (outClass != null) {
                     retVal = new Gson().fromJson(reply, outClass);
                 }
+            } else if ((response.getStatus() == HttpStatus.CREATED_201)) {
+                // success nothing to return ignore
+            } else {
+                logger.debug("Request failed with unexpected response code {}", response.getStatus());
             }
         } catch (ExecutionException e) {
             logger.debug("Error in handling request: ", e);
@@ -125,7 +129,6 @@ public class ApiAccess {
             logger.debug("Handling request interrupted: ", e);
             Thread.currentThread().interrupt();
         }
-
         return retVal;
     }
 
@@ -138,7 +141,7 @@ public class ApiAccess {
      * @return The result of the request or null
      * @throws TimeoutException Thrown when a request times out
      */
-    public <TOut> TOut doAuthenticatedGet(String url, Class<TOut> outClass) throws TimeoutException {
+    public @Nullable <TOut> TOut doAuthenticatedGet(String url, Class<TOut> outClass) throws TimeoutException {
         return doAuthenticatedRequest(HttpMethod.GET, url, null, outClass);
     }
 
@@ -161,16 +164,16 @@ public class ApiAccess {
      * @param method The HTTP method to use (POST, GET, ...)
      * @param url The URL to query
      * @param headers The optional additional headers to apply, can be null
-     * @param requestContainer The object to use as JSON data for the request
+     * @param requestContainer The object to use as JSON data for the request, can be null
-     * @param outClass The type of the requested result
+     * @param outClass The type of the requested result, can be null
      * @return The result of the request or null
      * @throws TimeoutException Thrown when a request times out
      */
-    private <TOut> TOut doRequest(HttpMethod method, String url, Map<String, String> headers, Object requestContainer,
+    private @Nullable <TOut> TOut doRequest(HttpMethod method, String url, Map<String, String> headers,
-            Class<TOut> outClass) throws TimeoutException {
+            @Nullable Object requestContainer, @Nullable Class<TOut> outClass) throws TimeoutException {
         String json = null;
         if (requestContainer != null) {
-            json = this.gson.toJson(requestContainer);
+            json = gson.toJson(requestContainer);
         }
 
         return doRequest(method, url, headers, json, "application/json", outClass);
@@ -188,17 +191,19 @@ public class ApiAccess {
      * @return The result of the request or null
      * @throws TimeoutException Thrown when a request times out
      */
-    private <TOut> TOut doAuthenticatedRequest(HttpMethod method, String url, Object requestContainer,
+    private @Nullable <TOut> TOut doAuthenticatedRequest(HttpMethod method, String url,
-            Class<TOut> outClass) throws TimeoutException {
+            @Nullable Object requestContainer, @Nullable Class<TOut> outClass) throws TimeoutException {
-        Map<String, String> headers = null;
+        Map<String, String> headers = new HashMap<>();
-        if (authenticationData != null) {
+        Authentication localAuthenticationData = authenticationData;
-            headers = new HashMap<>();
+        String localApplicationId = applicationId;
 
-            headers.put("Authorization", "Bearer " + authenticationData.getAccessToken());
+        if (localAuthenticationData != null) {
-            headers.put("applicationId", applicationId);
+            headers.put("Authorization", "Bearer " + localAuthenticationData.getAccessToken());
-            headers.put("Accept",
-                    "application/json, application/xml, text/json, text/x-json, text/javascript, text/xml");
         }
+        if (localApplicationId != null) {
+            headers.put("applicationId", localApplicationId);
+        }
+        headers.put("Accept", "application/json, application/xml, text/json, text/x-json, text/javascript, text/xml");
 
         return doRequest(method, url, headers, requestContainer, outClass);
     }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/EvohomeApiClient.java

@@ -19,18 +19,20 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.concurrent.TimeoutException;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jetty.client.HttpClient;
 import org.eclipse.jetty.http.HttpMethod;
-import org.openhab.binding.evohome.internal.api.models.v2.request.HeatSetPoint;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.request.HeatSetPoint;
-import org.openhab.binding.evohome.internal.api.models.v2.request.HeatSetPointBuilder;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.request.HeatSetPointBuilder;
-import org.openhab.binding.evohome.internal.api.models.v2.request.Mode;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.request.Mode;
-import org.openhab.binding.evohome.internal.api.models.v2.request.ModeBuilder;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.request.ModeBuilder;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Authentication;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Authentication;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Location;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Location;
-import org.openhab.binding.evohome.internal.api.models.v2.response.LocationStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.LocationStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Locations;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Locations;
-import org.openhab.binding.evohome.internal.api.models.v2.response.LocationsStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.LocationsStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.UserAccount;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.UserAccount;
 import org.openhab.binding.evohome.internal.configuration.EvohomeAccountConfiguration;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -41,6 +43,7 @@ import org.slf4j.LoggerFactory;
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeApiClient {
 
     private static final String APPLICATION_ID = "b013aa26-9724-4dbd-8897-048b9aada249";
@@ -52,8 +55,8 @@ public class EvohomeApiClient {
     private final ApiAccess apiAccess;
 
     private Locations locations = new Locations();
-    private UserAccount useraccount;
+    private @Nullable UserAccount useraccount;
-    private LocationsStatus locationsStatus;
+    private @Nullable LocationsStatus locationsStatus;
 
     /**
      * Creates a new API client based on the V2 API interface
@@ -72,7 +75,7 @@ public class EvohomeApiClient {
     public void close() {
         apiAccess.setAuthentication(null);
         useraccount = null;
-        locations = null;
+        locations = new Locations();
         locationsStatus = null;
     }
 
@@ -113,7 +116,7 @@ public class EvohomeApiClient {
         return locations;
     }
 
-    public LocationsStatus getInstallationStatus() {
+    public @Nullable LocationsStatus getInstallationStatus() {
         return locationsStatus;
     }
 
@@ -139,33 +142,33 @@ public class EvohomeApiClient {
         apiAccess.doAuthenticatedPut(url, heatSetPoint);
     }
 
-    private UserAccount requestUserAccount() throws TimeoutException {
+    private @Nullable UserAccount requestUserAccount() throws TimeoutException {
         String url = EvohomeApiConstants.URL_V2_BASE + EvohomeApiConstants.URL_V2_ACCOUNT;
         return apiAccess.doAuthenticatedGet(url, UserAccount.class);
     }
 
     private Locations requestLocations() throws TimeoutException {
-        Locations locations = new Locations();
+        Locations locations = null;
-        if (useraccount != null) {
+        UserAccount localAccount = useraccount;
+        if (localAccount != null) {
             String url = EvohomeApiConstants.URL_V2_BASE + EvohomeApiConstants.URL_V2_INSTALLATION_INFO;
-            url = String.format(url, useraccount.getUserId());
+            url = String.format(url, localAccount.getUserId());
 
             locations = apiAccess.doAuthenticatedGet(url, Locations.class);
         }
-        return locations;
+        return locations != null ? locations : new Locations();
     }
 
     private LocationsStatus requestLocationsStatus() throws TimeoutException {
         LocationsStatus locationsStatus = new LocationsStatus();
 
-        if (locations != null) {
+        for (Location location : locations) {
-            for (Location location : locations) {
+            String url = EvohomeApiConstants.URL_V2_BASE + EvohomeApiConstants.URL_V2_LOCATION_STATUS;
-                String url = EvohomeApiConstants.URL_V2_BASE + EvohomeApiConstants.URL_V2_LOCATION_STATUS;
+            url = String.format(url, location.getLocationInfo().getLocationId());
-                url = String.format(url, location.getLocationInfo().getLocationId());
+            LocationStatus status = apiAccess.doAuthenticatedGet(url, LocationStatus.class);
-                LocationStatus status = apiAccess.doAuthenticatedGet(url, LocationStatus.class);
+            locationsStatus.add(status);
-                locationsStatus.add(status);
-            }
         }
+
         return locationsStatus;
     }
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/EvohomeApiClientException.java

@@ -12,13 +12,17 @@
  */
 package org.openhab.binding.evohome.internal.api;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
 /**
  * Exception for errors from the API Client.
  *
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeApiClientException extends Exception {
+    private static final long serialVersionUID = 1L;
 
     public EvohomeApiClientException() {
     }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/EvohomeApiConstants.java

@@ -12,12 +12,15 @@
  */
 package org.openhab.binding.evohome.internal.api;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
 /**
  * List of evohome API constants
  *
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeApiConstants {
     public static final String URL_V2_AUTH = "https://tccna.honeywell.com/Auth/OAuth/Token";
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/request/HeatSetPoint.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.request;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.request;
 
 import com.google.gson.annotations.SerializedName;
 
@@ -43,12 +43,15 @@ public class HeatSetPoint {
         timeUntil = null;
     }
 
+    @SuppressWarnings("unused")
     @SerializedName("heatSetpointValue")
     private double heatSetpointValue;
 
+    @SuppressWarnings("unused")
     @SerializedName("setpointMode")
     private String setpointMode;
 
+    @SuppressWarnings("unused")
     @SerializedName("timeUntil")
     private String timeUntil;
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/request/HeatSetPointBuilder.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.request;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.request;
 
 /**
  * Builder for heat set point API requests

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/request/Mode.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.request;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.request;
 
 import com.google.gson.annotations.SerializedName;
 
@@ -34,12 +34,15 @@ public class Mode {
         permanent = false;
     }
 
+    @SuppressWarnings("unused")
     @SerializedName("systemMode")
     private String systemMode;
 
+    @SuppressWarnings("unused")
     @SerializedName("timeUntil")
     private String timeUntil;
 
+    @SuppressWarnings("unused")
     @SerializedName("permanent")
     private boolean permanent;
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/request/ModeBuilder.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.request;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.request;
 
 /**
  * Builder for mode API requests

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/request/RequestBuilder.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.request;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.request;
 
 /**
  * Builder for API requests

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/request/TimedRequestBuilder.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.request;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.request;
 
 /**
  * Builder for timed API requests

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/ActiveFault.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/Authentication.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/Gateway.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/GatewayInfo.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/GatewayStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/HeatSetpointCapabilities.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/HeatSetpointStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/Location.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/LocationInfo.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/LocationOwner.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/LocationStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.ArrayList;
 import java.util.List;

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/Locations.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.ArrayList;
 
@@ -21,5 +21,5 @@ import java.util.ArrayList;
  *
  */
 public class Locations extends ArrayList<Location> {
-
+    private static final long serialVersionUID = 1L;
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/LocationsStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.ArrayList;
 
@@ -21,5 +21,5 @@ import java.util.ArrayList;
  *
  */
 public class LocationsStatus extends ArrayList<LocationStatus> {
-
+    private static final long serialVersionUID = 1L;
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/Mode.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/ScheduleCapabilities.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/SystemModeStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/TemperatureControlSystem.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/TemperatureControlSystemStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/TemperatureStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/TimeZone.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/UserAccount.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/Zone.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import com.google.gson.annotations.SerializedName;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/api/models/v2/dto/response/ZoneStatus.java

@@ -10,7 +10,7 @@
  *
  * SPDX-License-Identifier: EPL-2.0
  */
-package org.openhab.binding.evohome.internal.api.models.v2.response;
+package org.openhab.binding.evohome.internal.api.models.v2.dto.response;
 
 import java.util.List;
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/configuration/EvohomeAccountConfiguration.java

@@ -12,15 +12,18 @@
  */
 package org.openhab.binding.evohome.internal.configuration;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
 /**
  * Contains the configuration of the binding.
  *
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeAccountConfiguration {
-    public String username;
+    public String username = "";
-    public String password;
+    public String password = "";
-    public String applicationId;
+    public String applicationId = "";
     public int refreshInterval;
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/configuration/EvohomeTemperatureControlSystemConfiguration.java

@@ -12,13 +12,16 @@
  */
 package org.openhab.binding.evohome.internal.configuration;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
 /**
  * Contains the configuration of the binding.
  *
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeTemperatureControlSystemConfiguration {
-    public String id;
+    public String id = "";
-    public String name;
+    public String name = "";
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/configuration/EvohomeThingConfiguration.java

@@ -12,13 +12,16 @@
  */
 package org.openhab.binding.evohome.internal.configuration;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+
 /**
  * Contains the common configuration definition of an evohome Thing
  *
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeThingConfiguration {
-    public String id;
+    public String id = "";
-    public String name;
+    public String name = "";
 }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/discovery/EvohomeDiscoveryService.java

@@ -15,11 +15,13 @@ package org.openhab.binding.evohome.internal.discovery;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.binding.evohome.internal.EvohomeBindingConstants;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Gateway;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Gateway;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Location;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Location;
-import org.openhab.binding.evohome.internal.api.models.v2.response.TemperatureControlSystem;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Locations;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Zone;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.TemperatureControlSystem;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Zone;
 import org.openhab.binding.evohome.internal.handler.AccountStatusListener;
 import org.openhab.binding.evohome.internal.handler.EvohomeAccountBridgeHandler;
 import org.openhab.core.config.discovery.AbstractDiscoveryService;
@@ -37,6 +39,7 @@ import org.slf4j.LoggerFactory;
  * @author Jasper van Zuijlen - Background discovery
  *
  */
+@NonNullByDefault
 public class EvohomeDiscoveryService extends AbstractDiscoveryService implements AccountStatusListener {
     private final Logger logger = LoggerFactory.getLogger(EvohomeDiscoveryService.class);
     private static final int TIMEOUT = 5;
@@ -86,18 +89,29 @@ public class EvohomeDiscoveryService extends AbstractDiscoveryService implements
             logger.debug("Evohome Gateway not online, scanning postponed");
             return;
         }
+        Locations localEvohomeConfig = bridge.getEvohomeConfig();
 
-        for (Location location : bridge.getEvohomeConfig()) {
+        if (localEvohomeConfig == null) {
+            return;
+        }
+        for (Location location : localEvohomeConfig) {
+            if (location == null) {
+                continue;
+            }
             for (Gateway gateway : location.getGateways()) {
                 for (TemperatureControlSystem tcs : gateway.getTemperatureControlSystems()) {
+                    if (tcs == null) {
+                        continue;
+                    }
                     addDisplayDiscoveryResult(location, tcs);
                     for (Zone zone : tcs.getZones()) {
-                        addZoneDiscoveryResult(location, zone);
+                        if (zone != null) {
+                            addZoneDiscoveryResult(location, zone);
+                        }
                     }
                 }
             }
         }
-
         stopScan();
     }
 

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/handler/AccountStatusListener.java

@@ -12,6 +12,7 @@
  */
 package org.openhab.binding.evohome.internal.handler;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.core.thing.ThingStatus;
 
 /**
@@ -20,6 +21,7 @@ import org.openhab.core.thing.ThingStatus;
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public interface AccountStatusListener {
 
     /**

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/handler/BaseEvohomeHandler.java

@@ -12,7 +12,9 @@
  */
 package org.openhab.binding.evohome.internal.handler;
 
-import org.openhab.binding.evohome.internal.api.models.v2.response.Locations;
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Locations;
 import org.openhab.binding.evohome.internal.configuration.EvohomeThingConfiguration;
 import org.openhab.core.thing.Bridge;
 import org.openhab.core.thing.Thing;
@@ -25,8 +27,9 @@ import org.openhab.core.thing.binding.BaseThingHandler;
  *
  * @author Jasper van Zuijlen - Initial contribution
  */
+@NonNullByDefault
 public abstract class BaseEvohomeHandler extends BaseThingHandler {
-    private EvohomeThingConfiguration configuration;
+    private EvohomeThingConfiguration configuration = new EvohomeThingConfiguration();
 
     public BaseEvohomeHandler(Thing thing) {
         super(thing);
@@ -40,14 +43,10 @@ public abstract class BaseEvohomeHandler extends BaseThingHandler {
 
     @Override
     public void dispose() {
-        configuration = null;
     }
 
     public String getId() {
-        if (configuration != null) {
+        return configuration.id;
-            return configuration.id;
-        }
-        return null;
     }
 
     /**
@@ -64,7 +63,7 @@ public abstract class BaseEvohomeHandler extends BaseThingHandler {
      *
      * @return The evohome brdige
      */
-    protected EvohomeAccountBridgeHandler getEvohomeBridge() {
+    protected @Nullable EvohomeAccountBridgeHandler getEvohomeBridge() {
         Bridge bridge = getBridge();
         if (bridge != null) {
             return (EvohomeAccountBridgeHandler) bridge.getHandler();
@@ -78,10 +77,10 @@ public abstract class BaseEvohomeHandler extends BaseThingHandler {
      *
      * @return The current evohome configuration
      */
-    protected Locations getEvohomeConfig() {
+    protected @Nullable Locations getEvohomeConfig() {
-        EvohomeAccountBridgeHandler bridge = getEvohomeBridge();
+        EvohomeAccountBridgeHandler bridgeAccountHandler = getEvohomeBridge();
-        if (bridge != null) {
+        if (bridgeAccountHandler != null) {
-            return bridge.getEvohomeConfig();
+            return bridgeAccountHandler.getEvohomeConfig();
         }
 
         return null;
@@ -115,7 +114,7 @@ public abstract class BaseEvohomeHandler extends BaseThingHandler {
      * @param detail The status detail value
      * @param message The message to show with the status
      */
-    protected void updateEvohomeThingStatus(ThingStatus newStatus, ThingStatusDetail detail, String message) {
+    protected void updateEvohomeThingStatus(ThingStatus newStatus, ThingStatusDetail detail, @Nullable String message) {
         // Prevent spamming the log file
         if (!newStatus.equals(getThing().getStatus())) {
             updateStatus(newStatus, detail, message);
@@ -128,10 +127,7 @@ public abstract class BaseEvohomeHandler extends BaseThingHandler {
      * @param configuration The configuration to check
      */
     private void checkConfig() {
-        if (configuration == null) {
+        if (configuration.id.isEmpty()) {
-            updateStatus(ThingStatus.OFFLINE, ThingStatusDetail.CONFIGURATION_ERROR,
-                    "Configuration is missing or corrupted");
-        } else if (configuration.id == null || configuration.id.isEmpty()) {
             updateStatus(ThingStatus.OFFLINE, ThingStatusDetail.CONFIGURATION_ERROR, "Id not configured");
         }
     }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/handler/EvohomeAccountBridgeHandler.java

@@ -22,19 +22,21 @@ import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.TimeoutException;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.eclipse.jetty.client.HttpClient;
 import org.openhab.binding.evohome.internal.RunnableWithTimeout;
 import org.openhab.binding.evohome.internal.api.EvohomeApiClient;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Gateway;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Gateway;
-import org.openhab.binding.evohome.internal.api.models.v2.response.GatewayStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.GatewayStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Location;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Location;
-import org.openhab.binding.evohome.internal.api.models.v2.response.LocationStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.LocationStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Locations;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Locations;
-import org.openhab.binding.evohome.internal.api.models.v2.response.LocationsStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.LocationsStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.TemperatureControlSystem;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.TemperatureControlSystem;
-import org.openhab.binding.evohome.internal.api.models.v2.response.TemperatureControlSystemStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.TemperatureControlSystemStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.Zone;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.Zone;
-import org.openhab.binding.evohome.internal.api.models.v2.response.ZoneStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.ZoneStatus;
 import org.openhab.binding.evohome.internal.configuration.EvohomeAccountConfiguration;
 import org.openhab.core.thing.Bridge;
 import org.openhab.core.thing.ChannelUID;
@@ -54,15 +56,16 @@ import org.slf4j.LoggerFactory;
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
 
     private final Logger logger = LoggerFactory.getLogger(EvohomeAccountBridgeHandler.class);
     private final HttpClient httpClient;
-    private EvohomeAccountConfiguration configuration;
+    private EvohomeAccountConfiguration configuration = new EvohomeAccountConfiguration();
-    private EvohomeApiClient apiClient;
+    private @Nullable EvohomeApiClient apiClient;
     private List<AccountStatusListener> listeners = new CopyOnWriteArrayList<>();
 
-    protected ScheduledFuture<?> refreshTask;
+    protected @Nullable ScheduledFuture<?> refreshTask;
 
     public EvohomeAccountBridgeHandler(Bridge thing, HttpClient httpClient) {
         super(thing);
@@ -73,13 +76,14 @@ public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
     public void initialize() {
         configuration = getConfigAs(EvohomeAccountConfiguration.class);
 
-        if (checkConfig()) {
+        if (checkConfig(configuration)) {
             apiClient = new EvohomeApiClient(configuration, this.httpClient);
 
             // Initialization can take a while, so kick it off on a separate thread
             scheduler.schedule(() -> {
-                if (apiClient.login()) {
+                EvohomeApiClient localApiCLient = apiClient;
-                    if (checkInstallationInfoHasDuplicateIds(apiClient.getInstallationInfo())) {
+                if (localApiCLient != null && localApiCLient.login()) {
+                    if (checkInstallationInfoHasDuplicateIds(localApiCLient.getInstallationInfo())) {
                         startRefreshTask();
                     } else {
                         updateAccountStatus(ThingStatus.OFFLINE, ThingStatusDetail.COMMUNICATION_ERROR,
@@ -104,24 +108,41 @@ public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
     public void handleCommand(ChannelUID channelUID, Command command) {
     }
 
-    public Locations getEvohomeConfig() {
+    public @Nullable Locations getEvohomeConfig() {
-        return apiClient.getInstallationInfo();
+        EvohomeApiClient localApiCLient = apiClient;
+        if (localApiCLient != null) {
+            return localApiCLient.getInstallationInfo();
+        }
+        return null;
     }
 
-    public LocationsStatus getEvohomeStatus() {
+    public @Nullable LocationsStatus getEvohomeStatus() {
-        return apiClient.getInstallationStatus();
+        EvohomeApiClient localApiCLient = apiClient;
+        if (localApiCLient != null) {
+            return localApiCLient.getInstallationStatus();
+        }
+        return null;
     }
 
     public void setTcsMode(String tcsId, String mode) {
-        tryToCall(() -> apiClient.setTcsMode(tcsId, mode));
+        EvohomeApiClient localApiCLient = apiClient;
+        if (localApiCLient != null) {
+            tryToCall(() -> localApiCLient.setTcsMode(tcsId, mode));
+        }
     }
 
     public void setPermanentSetPoint(String zoneId, double doubleValue) {
-        tryToCall(() -> apiClient.setHeatingZoneOverride(zoneId, doubleValue));
+        EvohomeApiClient localApiCLient = apiClient;
+        if (localApiCLient != null) {
+            tryToCall(() -> localApiCLient.setHeatingZoneOverride(zoneId, doubleValue));
+        }
     }
 
     public void cancelSetPointOverride(String zoneId) {
-        tryToCall(() -> apiClient.cancelHeatingZoneOverride(zoneId));
+        EvohomeApiClient localApiCLient = apiClient;
+        if (localApiCLient != null) {
+            tryToCall(() -> localApiCLient.cancelHeatingZoneOverride(zoneId));
+        }
     }
 
     public void addAccountStatusListener(AccountStatusListener listener) {
@@ -164,26 +185,27 @@ public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
     }
 
     private void disposeApiClient() {
-        if (apiClient != null) {
+        EvohomeApiClient localApiClient = apiClient;
-            apiClient.logout();
+        if (localApiClient != null) {
+            localApiClient.logout();
+            this.apiClient = null;
         }
-        apiClient = null;
     }
 
     private void disposeRefreshTask() {
-        if (refreshTask != null) {
+        ScheduledFuture<?> localRefreshTask = refreshTask;
-            refreshTask.cancel(true);
+        if (localRefreshTask != null) {
+            localRefreshTask.cancel(true);
+            this.refreshTask = null;
         }
     }
 
-    private boolean checkConfig() {
+    private boolean checkConfig(EvohomeAccountConfiguration configuration) {
         String errorMessage = "";
 
-        if (configuration == null) {
+        if (configuration.username.isBlank()) {
-            errorMessage = "Configuration is missing or corrupted";
-        } else if (configuration.username == null || configuration.username.isEmpty()) {
             errorMessage = "Username not configured";
-        } else if (configuration.password == null || configuration.password.isEmpty()) {
+        } else if (configuration.password.isBlank()) {
             errorMessage = "Password not configured";
         } else {
             return true;
@@ -202,7 +224,10 @@ public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
 
     private void update() {
         try {
-            apiClient.update();
+            EvohomeApiClient localApiCLient = apiClient;
+            if (localApiCLient != null) {
+                localApiCLient.update();
+            }
             updateAccountStatus(ThingStatus.ONLINE);
             updateThings();
         } catch (Exception e) {
@@ -215,7 +240,7 @@ public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
         updateAccountStatus(newStatus, ThingStatusDetail.NONE, null);
     }
 
-    private void updateAccountStatus(ThingStatus newStatus, ThingStatusDetail detail, String message) {
+    private void updateAccountStatus(ThingStatus newStatus, ThingStatusDetail detail, @Nullable String message) {
         // Prevent spamming the log file
         if (!newStatus.equals(getThing().getStatus())) {
             updateStatus(newStatus, detail, message);
@@ -236,15 +261,32 @@ public class EvohomeAccountBridgeHandler extends BaseBridgeHandler {
         Map<String, String> zoneIdToTcsIdMap = new HashMap<>();
         Map<String, ThingStatus> idToTcsThingsStatusMap = new HashMap<>();
 
-        // First, create a lookup table
+        EvohomeApiClient localApiClient = apiClient;
-        for (LocationStatus location : apiClient.getInstallationStatus()) {
+        if (localApiClient != null) {
-            for (GatewayStatus gateway : location.getGateways()) {
+            // First, create a lookup table
-                for (TemperatureControlSystemStatus tcs : gateway.getTemperatureControlSystems()) {
+            LocationsStatus localLocationsStatus = localApiClient.getInstallationStatus();
-                    idToTcsMap.put(tcs.getSystemId(), tcs);
+            if (localLocationsStatus != null) {
-                    tcsIdToGatewayMap.put(tcs.getSystemId(), gateway);
+                for (LocationStatus location : localLocationsStatus) {
-                    for (ZoneStatus zone : tcs.getZones()) {
+                    for (GatewayStatus gateway : location.getGateways()) {
-                        idToZoneMap.put(zone.getZoneId(), zone);
+                        if (gateway == null) {
-                        zoneIdToTcsIdMap.put(zone.getZoneId(), tcs.getSystemId());
+                            continue;
+                        }
+                        for (TemperatureControlSystemStatus tcs : gateway.getTemperatureControlSystems()) {
+                            String systemId = tcs.getSystemId();
+                            if (systemId != null) {
+                                idToTcsMap.put(systemId, tcs);
+                                tcsIdToGatewayMap.put(systemId, gateway);
+                            }
+                            for (ZoneStatus zone : tcs.getZones()) {
+                                String zoneId = zone.getZoneId();
+                                if (zoneId != null) {
+                                    idToZoneMap.put(zoneId, zone);
+                                    if (systemId != null) {
+                                        zoneIdToTcsIdMap.put(zoneId, systemId);
+                                    }
+                                }
+                            }
+                        }
                     }
                 }
             }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/handler/EvohomeHeatingZoneHandler.java

@@ -12,10 +12,15 @@
  */
 package org.openhab.binding.evohome.internal.handler;
 
+import javax.measure.quantity.Temperature;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.binding.evohome.internal.EvohomeBindingConstants;
-import org.openhab.binding.evohome.internal.api.models.v2.response.ZoneStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.ZoneStatus;
-import org.openhab.core.library.types.DecimalType;
+import org.openhab.core.library.types.QuantityType;
 import org.openhab.core.library.types.StringType;
+import org.openhab.core.library.unit.SIUnits;
 import org.openhab.core.thing.ChannelUID;
 import org.openhab.core.thing.Thing;
 import org.openhab.core.thing.ThingStatus;
@@ -30,12 +35,14 @@ import org.openhab.core.types.RefreshType;
  * @author Jasper van Zuijlen - Initial contribution
  * @author Neil Renaud - Working implementation
  * @author Jasper van Zuijlen - Refactor + Permanent Zone temperature setting
+ * @author Leo Siepel - Add UoM
  */
+@NonNullByDefault
 public class EvohomeHeatingZoneHandler extends BaseEvohomeHandler {
 
     private static final int CANCEL_SET_POINT_OVERRIDE = 0;
-    private ThingStatus tcsStatus;
+    private @Nullable ThingStatus tcsStatus;
-    private ZoneStatus zoneStatus;
+    private @Nullable ZoneStatus zoneStatus;
 
     public EvohomeHeatingZoneHandler(Thing thing) {
         super(thing);
@@ -46,7 +53,7 @@ public class EvohomeHeatingZoneHandler extends BaseEvohomeHandler {
         super.initialize();
     }
 
-    public void update(ThingStatus tcsStatus, ZoneStatus zoneStatus) {
+    public void update(@Nullable ThingStatus tcsStatus, @Nullable ZoneStatus zoneStatus) {
         this.tcsStatus = tcsStatus;
         this.zoneStatus = zoneStatus;
 
@@ -62,11 +69,11 @@ public class EvohomeHeatingZoneHandler extends BaseEvohomeHandler {
             updateEvohomeThingStatus(ThingStatus.ONLINE);
 
             updateState(EvohomeBindingConstants.ZONE_TEMPERATURE_CHANNEL,
-                    new DecimalType(zoneStatus.getTemperature().getTemperature()));
+                    new QuantityType<Temperature>(zoneStatus.getTemperature().getTemperature(), SIUnits.CELSIUS));
             updateState(EvohomeBindingConstants.ZONE_SET_POINT_STATUS_CHANNEL,
                     new StringType(zoneStatus.getHeatSetpoint().getSetpointMode()));
-            updateState(EvohomeBindingConstants.ZONE_SET_POINT_CHANNEL,
+            updateState(EvohomeBindingConstants.ZONE_SET_POINT_CHANNEL, new QuantityType<Temperature>(
-                    new DecimalType(zoneStatus.getHeatSetpoint().getTargetTemperature()));
+                    zoneStatus.getHeatSetpoint().getTargetTemperature(), SIUnits.CELSIUS));
         }
     }
 
@@ -78,16 +85,19 @@ public class EvohomeHeatingZoneHandler extends BaseEvohomeHandler {
             EvohomeAccountBridgeHandler bridge = getEvohomeBridge();
             if (bridge != null) {
                 String channelId = channelUID.getId();
-                if (EvohomeBindingConstants.ZONE_SET_POINT_CHANNEL.equals(channelId)
+                if (EvohomeBindingConstants.ZONE_SET_POINT_CHANNEL.equals(channelId)) {
-                        && command instanceof DecimalType) {
+                    if (command instanceof QuantityType) {
-                    double newTemp = ((DecimalType) command).doubleValue();
+                        QuantityType<?> state = ((QuantityType<?>) command).toUnit(SIUnits.CELSIUS);
-                    if (newTemp == CANCEL_SET_POINT_OVERRIDE) {
+                        double newTempInCelsius = state.doubleValue();
-                        bridge.cancelSetPointOverride(getEvohomeThingConfig().id);
+
-                    } else if (newTemp < 5) {
+                        if (newTempInCelsius == CANCEL_SET_POINT_OVERRIDE) {
-                        newTemp = 5;
+                            bridge.cancelSetPointOverride(getEvohomeThingConfig().id);
-                    }
+                        } else if (newTempInCelsius < 5) {
-                    if (newTemp >= 5 && newTemp <= 35) {
+                            newTempInCelsius = 5;
-                        bridge.setPermanentSetPoint(getEvohomeThingConfig().id, newTemp);
+                        }
+                        if (newTempInCelsius >= 5 && newTempInCelsius <= 35) {
+                            bridge.setPermanentSetPoint(getEvohomeThingConfig().id, newTempInCelsius);
+                        }
                     }
                 }
             }

bundles/org.openhab.binding.evohome/src/main/java/org/openhab/binding/evohome/internal/handler/EvohomeTemperatureControlSystemHandler.java

@@ -12,9 +12,11 @@
  */
 package org.openhab.binding.evohome.internal.handler;
 
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.binding.evohome.internal.EvohomeBindingConstants;
-import org.openhab.binding.evohome.internal.api.models.v2.response.GatewayStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.GatewayStatus;
-import org.openhab.binding.evohome.internal.api.models.v2.response.TemperatureControlSystemStatus;
+import org.openhab.binding.evohome.internal.api.models.v2.dto.response.TemperatureControlSystemStatus;
 import org.openhab.core.library.types.StringType;
 import org.openhab.core.thing.ChannelUID;
 import org.openhab.core.thing.Thing;
@@ -29,9 +31,10 @@ import org.openhab.core.types.RefreshType;
  * @author Jasper van Zuijlen - Initial contribution
  *
  */
+@NonNullByDefault
 public class EvohomeTemperatureControlSystemHandler extends BaseEvohomeHandler {
-    private GatewayStatus gatewayStatus;
+    private @Nullable GatewayStatus gatewayStatus;
-    private TemperatureControlSystemStatus tcsStatus;
+    private @Nullable TemperatureControlSystemStatus tcsStatus;
 
     public EvohomeTemperatureControlSystemHandler(Thing thing) {
         super(thing);
@@ -42,7 +45,7 @@ public class EvohomeTemperatureControlSystemHandler extends BaseEvohomeHandler {
         super.initialize();
     }
 
-    public void update(GatewayStatus gatewayStatus, TemperatureControlSystemStatus tcsStatus) {
+    public void update(@Nullable GatewayStatus gatewayStatus, @Nullable TemperatureControlSystemStatus tcsStatus) {
         this.gatewayStatus = gatewayStatus;
         this.tcsStatus = tcsStatus;
 

bundles/org.openhab.binding.evohome/src/main/resources/OH-INF/thing/channels.xml

@@ -20,19 +20,27 @@
 		</state>
 	</channel-type>
 	<channel-type id="temperature">
-		<item-type>Number</item-type>
+		<item-type>Number:Temperature</item-type>
 		<label>Temperature</label>
 		<description>Current zone temperature</description>
 		<category>temperature</category>
-		<state readOnly="true" pattern="%.1f °C">
+		<tags>
+			<tag>Measurement</tag>
+			<tag>Temperature</tag>
+		</tags>
+		<state readOnly="true" pattern="%.1f %unit%">
 		</state>
 	</channel-type>
 	<channel-type id="setpoint">
-		<item-type>Number</item-type>
+		<item-type>Number:Temperature</item-type>
 		<label>Set Point</label>
 		<description>Gets or sets the set point of this zone (0 cancels the override).</description>
 		<category>heating</category>
-		<state min="0.0" max="35.0" step="0.5" pattern="%.1f °C"/>
+		<tags>
+			<tag>Setpoint</tag>
+			<tag>Temperature</tag>
+		</tags>
+		<state min="0.0" max="35.0" step="0.5" pattern="%.1f %unit%"/>
 	</channel-type>
 	<channel-type id="setpointstatus">
 		<item-type>String</item-type>