[miele] Fix mDNS issue where hub repeatedly disappears from, resp. reappears in, the Inbox.

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

@@ -29,6 +29,12 @@ The types of appliances that are supported by this binding are:
 The binding is able to auto-discover the Miele XGW3000 gateway.
 When an XGW3000 gateway is discovered, all appliances can be subsequently discovered.
 
+## Binding Configuration
+
+The XGW3000 gateway is sometimes a few seconds late in re-announcing itself on the network.
+This means that it might repeatedly appear in, resp. and disappear from, the Inbox.
+To avoid this, the binding has a configuration parameter `removalGracePeriod` which delays such Inbox disappearances.
+The default value is 30 seconds.
 
 ## Thing Configuration
 

bundles/org.openhab.binding.miele/src/main/java/org/openhab/binding/miele/internal/MieleBindingConstants.java

@@ -114,4 +114,5 @@ public class MieleBindingConstants {
     public static final String USER_NAME = "userName";
     public static final String PASSWORD = "password";
     public static final String LANGUAGE = "language";
+    public static final String REMOVAL_GRACE_PERIOD = "removalGracePeriod";
 }

bundles/org.openhab.binding.miele/src/main/java/org/openhab/binding/miele/internal/discovery/MieleMDNSDiscoveryParticipant.java

@@ -16,19 +16,26 @@
 import java.net.InetAddress;
 import java.net.Socket;
 import java.util.Collections;
+import java.util.Dictionary;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Set;
 
 import javax.jmdns.ServiceInfo;
 
+import org.eclipse.jdt.annotation.Nullable;
 import org.openhab.binding.miele.internal.MieleBindingConstants;
 import org.openhab.core.config.discovery.DiscoveryResult;
 import org.openhab.core.config.discovery.DiscoveryResultBuilder;
 import org.openhab.core.config.discovery.mdns.MDNSDiscoveryParticipant;
+import org.openhab.core.config.discovery.mdns.internal.MDNSDiscoveryService;
 import org.openhab.core.thing.ThingTypeUID;
 import org.openhab.core.thing.ThingUID;
+import org.osgi.service.cm.Configuration;
+import org.osgi.service.cm.ConfigurationAdmin;
+import org.osgi.service.component.annotations.Activate;
 import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -48,6 +55,14 @@ public class MieleMDNSDiscoveryParticipant implements MDNSDiscoveryParticipant {
     private static final String SERVICE_NAME = "mieleathome";
     private static final String PATH_PROPERTY_NAME = "path";
 
+    private final ConfigurationAdmin configAdmin;
+    private long removalGracePeriodSeconds = 30;
+
+    @Activate
+    public MieleMDNSDiscoveryParticipant(final @Reference ConfigurationAdmin configAdmin) {
+        this.configAdmin = configAdmin;
+    }
+
     @Override
     public Set<ThingTypeUID> getSupportedThingTypeUIDs() {
         return Collections.singleton(MieleBindingConstants.THING_TYPE_XGW3000);
@@ -113,4 +128,27 @@ private boolean isMieleGateway(ServiceInfo service) {
         return service.getApplication().contains(SERVICE_NAME) && service.getPropertyString(PATH_PROPERTY_NAME) != null
                 && service.getPropertyString(PATH_PROPERTY_NAME).equalsIgnoreCase(PATH_TO_CHECK_FOR_XGW3000);
     }
+
+    /*
+     * Miele devices are sometimes a few seconds late in updating their mDNS announcements, which means that they are
+     * repeatedly removed from, and (re)added to, the Inbox. To prevent this, we override this method to specify an
+     * additional delay period (grace period) to wait before the device is removed from the Inbox.
+     */
+    @Override
+    public long getRemovalGracePeriodSeconds(ServiceInfo service) {
+        try {
+            Configuration conf = configAdmin.getConfiguration("binding.miele");
+            Dictionary<String, @Nullable Object> properties = conf.getProperties();
+            if (properties != null) {
+                Object property = properties.get(MieleBindingConstants.REMOVAL_GRACE_PERIOD);
+                if (property != null) {
+                    removalGracePeriodSeconds = Long.parseLong(property.toString());
+                }
+            }
+        } catch (IOException | IllegalStateException | NumberFormatException e) {
+            // fall through to pre-initialised (default) value
+        }
+        logger.trace("getRemovalGracePeriodSeconds={}", removalGracePeriodSeconds);
+        return removalGracePeriodSeconds;
+    }
 }

bundles/org.openhab.binding.miele/src/main/resources/OH-INF/binding/binding.xml

@@ -6,4 +6,13 @@
 	<name>Miele Binding</name>
 	<description>This is the binding for Miele@home appliances</description>
 
+	<config-description>
+		<parameter name="removalGracePeriod" type="integer" min="0" step="1" unit="s">
+			<label>Removal Grace Period</label>
+			<description>Extra grace period (seconds) that mDNS discovery shall wait before removing a lost Bridge from the
+				Inbox. Default is 30 seconds.</description>
+			<default>30</default>
+		</parameter>
+	</config-description>
+
 </binding:binding>

bundles/org.openhab.binding.miele/src/main/resources/OH-INF/i18n/miele.properties

@@ -3,6 +3,11 @@
 binding.miele.name = Miele Binding
 binding.miele.description = This is the binding for Miele@home appliances
 
+# binding config
+
+binding.config.miele.removalGracePeriod.label = Removal Grace Period
+binding.config.miele.removalGracePeriod.description = Extra grace period (seconds) that mDNS discovery shall wait before removing a lost Bridge from the Inbox. Default is 30 seconds.
+
 # thing types
 
 thing-type.miele.coffeemachine.label = Coffee Machine