various

- ignore null DTO fields to prevent NPE risk
- fix inherited exception stack trace logging

Signed-off-by: Andrew Fiddian-Green <software@whitebear.ch>

Author: andrewfg

bundles/org.openhab.binding.homekit/src/main/java/org/openhab/binding/homekit/internal/dto/Characteristic.java

@@ -982,4 +982,11 @@ public String toString() {
     public @Nullable StatusCode getStatusCode() {
         return status instanceof Integer code ? StatusCode.from(code) : null;
     }
+
+    /**
+     * Return true if the characteristic is valid i.e. itself and its aid and iid fields are not null
+     */
+    public static boolean isValid(@Nullable Characteristic characteristic) {
+        return characteristic != null && characteristic.aid != null && characteristic.iid != null;
+    }
 }

bundles/org.openhab.binding.homekit/src/main/java/org/openhab/binding/homekit/internal/handler/HomekitAccessoryHandler.java

@@ -790,27 +790,40 @@ private void eventingPollingFinalize(Accessory accessory, Map<String, Channel> c
         if (aid == null) {
             return;
         }
+        List<Service> services = accessory.services;
+        if (services == null) {
+            return;
+        }
 
         for (Channel channel : channels.values()) {
             final ChannelUID channelUID = channel.getUID();
             if (CHANNEL_SNAPSHOT.equals(channelUID.getId())) {
                 continue; // skip camera snapshot channel
             }
             if (isLinked(channelUID)) {
-                Long iid = 0L;
+                Long iid;
                 boolean checkChannelLinkByIID = !channelUID.equals(lightModelClientHSBTypeChannel);
                 if (checkChannelLinkByIID && channel.getProperties().get(PROPERTY_IID) instanceof String iidProperty) {
                     try {
                         iid = Long.parseLong(iidProperty);
                     } catch (NumberFormatException e) {
                         continue; // error will already have been logged elsewhere
                     }
+                } else {
+                    iid = null;
+                }
+                if (checkChannelLinkByIID && iid == null) {
+                    continue;
                 }
 
                 nestedLoops: // break marker for nested loops below
-                for (Service service : accessory.services) {
+                for (Service service : services) {
+                    if (service == null || service.characteristics == null) {
+                        continue;
+                    }
                     for (Characteristic characteristic : service.characteristics) {
-                        if ((checkChannelLinkByIID && iid.equals(characteristic.iid))
+                        if (Characteristic.isValid(characteristic)
+                                && (checkChannelLinkByIID && characteristic.iid.equals(iid))
                                 || LIGHT_MODEL_RELEVANT_TYPES.contains(characteristic.getCharacteristicType())) {
                             Characteristic entry = new Characteristic();
                             entry.aid = aid;

bundles/org.openhab.binding.homekit/src/main/java/org/openhab/binding/homekit/internal/handler/HomekitBaseAccessoryHandler.java

@@ -15,6 +15,8 @@
 import static org.openhab.binding.homekit.internal.HomekitBindingConstants.*;
 
 import java.io.IOException;
+import java.io.PrintWriter;
+import java.io.StringWriter;
 import java.math.BigDecimal;
 import java.nio.charset.StandardCharsets;
 import java.security.NoSuchAlgorithmException;
@@ -682,10 +684,11 @@ private void enableEventsOrThrow(boolean enable) throws Exception {
         }
         Service service = new Service();
         service.characteristics = new ArrayList<>();
-        service.characteristics.addAll(getEventedCharacteristics().values().stream().map(cxx -> {
-            cxx.ev = enable;
-            return cxx;
-        }).toList());
+        service.characteristics
+                .addAll(getEventedCharacteristics().values().stream().filter(Characteristic::isValid).map(cxx -> {
+                    cxx.ev = enable;
+                    return cxx;
+                }).toList());
         if (service.characteristics.isEmpty()) {
             return;
         }
@@ -703,7 +706,7 @@ private void enableEventsOrThrow(boolean enable) throws Exception {
      * Called periodically by the refresh task and on-demand when RefreshType.REFRESH is called.
      */
     private synchronized void refresh() {
-        List<String> queries = getPolledCharacteristics().values().stream().filter(c -> c.iid != null && c.aid != null)
+        List<String> queries = getPolledCharacteristics().values().stream().filter(Characteristic::isValid)
                 .map(c -> "%s.%s".formatted(c.aid, c.iid)).toList();
         if (queries.isEmpty()) {
             return;
@@ -966,7 +969,13 @@ protected void scheduleSnapshotRefresh() {
     protected void onCommunicationError(Exception exception, String i18nSuffix) {
         String message = exception.getMessage();
         logger.debug("{} {} {}, reconnecting..", thing.getUID(), i18nSuffix, message);
-        logger.trace("{} stack trace", thing.getUID(), exception);
+        if (logger.isTraceEnabled()) {
+            try (StringWriter sw = new StringWriter(); PrintWriter pw = new PrintWriter(sw)) {
+                exception.printStackTrace(pw);
+                logger.trace("{}", sw.toString().trim());
+            } catch (IOException e) {
+            }
+        }
         String description = THING_STATUS_FMT.formatted("error." + i18nSuffix.replace(' ', '-'), message);
         updateStatus(ThingStatus.OFFLINE, ThingStatusDetail.COMMUNICATION_ERROR, description);
         scheduleConnectionAttempt();