[lcn] Refactor and fix null warnings (#9675)

Signed-off-by: Fabian Wolter <github@fabian-wolter.de>

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/LcnHandlerFactory.java

@@ -14,10 +14,7 @@ package org.openhab.binding.lcn.internal;
 
 import static org.openhab.binding.lcn.internal.LcnBindingConstants.*;
 
-import java.util.Collections;
 import java.util.Set;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
@@ -38,8 +35,8 @@ import org.osgi.service.component.annotations.Component;
 @NonNullByDefault
 @Component(configurationPid = "binding.lcn", service = ThingHandlerFactory.class)
 public class LcnHandlerFactory extends BaseThingHandlerFactory {
-    private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Collections.unmodifiableSet(
+    private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Set.of(THING_TYPE_PCK_GATEWAY,
-            Stream.of(THING_TYPE_PCK_GATEWAY, THING_TYPE_MODULE, THING_TYPE_GROUP).collect(Collectors.toSet()));
+            THING_TYPE_MODULE, THING_TYPE_GROUP);
 
     @Override
     public boolean supportsThingType(ThingTypeUID thingTypeUID) {

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/LcnModuleDiscoveryService.java

@@ -12,7 +12,6 @@
  */
 package org.openhab.binding.lcn.internal;
 
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
@@ -25,8 +24,6 @@ import java.util.concurrent.ScheduledFuture;
 import java.util.concurrent.TimeUnit;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.eclipse.jdt.annotation.Nullable;
@@ -69,8 +66,7 @@ public class LcnModuleDiscoveryService extends AbstractDiscoveryService
     private static final int MODULE_NAME_PART_COUNT = 2;
     private static final int DISCOVERY_TIMEOUT_SEC = 90;
     private static final int ACK_TIMEOUT_MS = 1000;
-    private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Collections
+    private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Set.of(LcnBindingConstants.THING_TYPE_MODULE);
-            .unmodifiableSet(Stream.of(LcnBindingConstants.THING_TYPE_MODULE).collect(Collectors.toSet()));
     private @Nullable PckGatewayHandler bridgeHandler;
     private final Map<LcnAddrMod, @Nullable Map<Integer, String>> moduleNames = new HashMap<>();
     private final Map<LcnAddrMod, DiscoveryResultBuilder> discoveryResultBuilders = new ConcurrentHashMap<>();

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/LcnModuleHandler.java

@@ -157,7 +157,6 @@ public class LcnModuleHandler extends BaseThingHandler {
      *
      * @throws LcnException when the handler is not initialized
      */
-    @SuppressWarnings("null")
     protected void requestFirmwareVersionAndSerialNumberIfNotSet() throws LcnException {
         String serialNumber = getThing().getProperties().get(Thing.PROPERTY_SERIAL_NUMBER);
         if (serialNumber == null || serialNumber.isEmpty()) {
@@ -241,7 +240,6 @@ public class LcnModuleHandler extends BaseThingHandler {
      *
      * @param pck the message without line termination
      */
-    @SuppressWarnings("null")
     public void handleStatusMessage(String pck) {
         for (AbstractLcnModuleSubHandler handler : subHandlers.values()) {
             if (handler.tryParse(pck)) {

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/connection/AbstractStateMachine.java

@@ -55,7 +55,7 @@ public abstract class AbstractStateMachine<T extends AbstractStateMachine<T, U>,
 
         state = newState;
 
-        state.startWorking();
+        newState.startWorking();
     }
 
     protected boolean isStateActive(AbstractState<?, ?> otherState) {

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/connection/Connection.java

@@ -21,7 +21,13 @@ import java.nio.channels.Channel;
 import java.nio.channels.CompletionHandler;
 import java.time.Instant;
 import java.time.temporal.ChronoUnit;
-import java.util.*;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Queue;
 import java.util.concurrent.BlockingQueue;
 import java.util.concurrent.LinkedBlockingQueue;
 import java.util.concurrent.ScheduledExecutorService;
@@ -133,7 +139,10 @@ public class Connection {
     public void onAck(LcnAddrMod addr, int code) {
         synchronized (modData) {
             if (modData.containsKey(addr)) {
-                modData.get(addr).onAck(code, this, this.settings.getTimeout(), System.nanoTime());
+                ModInfo modInfo = modData.get(addr);
+                if (modInfo != null) {
+                    modInfo.onAck(code, this, this.settings.getTimeout(), System.nanoTime());
+                }
             }
         }
     }

bundles/org.openhab.binding.lcn/src/main/java/org/openhab/binding/lcn/internal/pchkdiscovery/LcnPchkDiscoveryService.java

@@ -25,8 +25,6 @@ import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
-import java.util.stream.Collectors;
-import java.util.stream.Stream;
 
 import org.eclipse.jdt.annotation.NonNullByDefault;
 import org.openhab.binding.lcn.internal.LcnBindingConstants;
@@ -63,8 +61,8 @@ public class LcnPchkDiscoveryService extends AbstractDiscoveryService {
     private static final String PCHK_DISCOVERY_MULTICAST_ADDRESS = "234.5.6.7";
     private static final int PCHK_DISCOVERY_PORT = 4220;
     private static final int INTERFACE_TIMEOUT_SEC = 2;
-    private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Collections
+    private static final Set<ThingTypeUID> SUPPORTED_THING_TYPES_UIDS = Set
-            .unmodifiableSet(Stream.of(LcnBindingConstants.THING_TYPE_PCK_GATEWAY).collect(Collectors.toSet()));
+            .of(LcnBindingConstants.THING_TYPE_PCK_GATEWAY);
     private static final String DISCOVER_REQUEST = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><ServicesRequest xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xsi:noNamespaceSchemaLocation=\"servicesrequest.xsd\"><Version major=\"1\" minor=\"0\" /><Requester requestId=\"1\" type=\"openHAB\" major=\"1\" minor=\"0\">openHAB</Requester><Requests><Request xsi:type=\"EnumServices\" major=\"1\" minor=\"0\" name=\"LcnPchkBus\" /></Requests></ServicesRequest>";
 
     public LcnPchkDiscoveryService() throws IllegalArgumentException {

bundles/org.openhab.binding.lcn/src/test/java/org/openhab/binding/lcn/internal/subhandler/AbstractTestLcnModuleSubHandler.java

@@ -29,7 +29,7 @@ import org.openhab.binding.lcn.internal.connection.ModInfo;
  * @author Fabian Wolter - Initial contribution
  */
 @ExtendWith(MockitoExtension.class)
-@MockitoSettings(strictness = Strictness.WARN)
+@MockitoSettings(strictness = Strictness.LENIENT)
 @NonNullByDefault
 public class AbstractTestLcnModuleSubHandler {