Fix sonar warnings, enable code coverage

build.gradle

@@ -1,5 +1,6 @@
 plugins {
     id 'java'
+    id 'jacoco'
     id "com.github.hierynomus.license" version "0.15.0"
     id "org.sonarqube" version "2.7"
 }

src/main/java/org/chris/portmapper/router/cling/ClingRegistryListener.java

@@ -51,6 +51,7 @@ public class ClingRegistryListener extends DefaultRegistryListener {
         try {
             return foundServices.poll(timeout, unit);
         } catch (final InterruptedException e) {
+            Thread.currentThread().interrupt();
             logger.warn("Interrupted when waiting for a service");
             return null;
         }
@@ -65,7 +66,10 @@ public class ClingRegistryListener extends DefaultRegistryListener {
         }
 
         logger.debug("Found connection service {}", connectionService);
-        foundServices.offer(connectionService);
+        final boolean success = foundServices.offer(connectionService);
+        if (!success) {
+            throw new IllegalStateException("Could not add new service");
+        }
     }
 
     protected Service<?, ?> discoverConnectionService(@SuppressWarnings("rawtypes") final Device<?, Device, ?> device) {

src/main/java/org/chris/portmapper/router/cling/action/AbstractClingAction.java

@@ -59,7 +59,7 @@ abstract class AbstractClingAction<T> implements ClingAction<T> {
                     + Arrays.toString(service.getActions()));
         }
         final ActionArgumentValue<RemoteService>[] argumentArray = getArguments(action);
-        return new ActionInvocation<RemoteService>(action, argumentArray);
+        return new ActionInvocation<>(action, argumentArray);
     }
 
     private ActionArgumentValue<RemoteService>[] getArguments(final Action<RemoteService> action) {
@@ -77,7 +77,8 @@ abstract class AbstractClingAction<T> implements ClingAction<T> {
             }
         }
         @SuppressWarnings("unchecked")
-        final ActionArgumentValue<RemoteService>[] array = actionArgumentValues.toArray(new ActionArgumentValue[0]);
+        final ActionArgumentValue<RemoteService>[] array = actionArgumentValues
+                .toArray(new ActionArgumentValue[0]);
         return array;
     }
 }

src/main/java/org/chris/portmapper/router/dummy/DummyRouter.java

@@ -47,7 +47,7 @@ public class DummyRouter extends AbstractRouter {
 
     @Override
     public void addPortMapping(final PortMapping mapping) {
-        logger.debug("Adding mapping " + mapping);
+        logger.debug("Adding mapping {}", mapping);
         mappings.add(mapping);
     }
 
@@ -83,14 +83,14 @@ public class DummyRouter extends AbstractRouter {
             logger.debug("Sleep 3s to simulate delay when fetching port mappings.");
             Thread.sleep(3000);
         } catch (final InterruptedException e) {
-            // ignore
+            Thread.currentThread().interrupt();
         }
         return mappings;
     }
 
     @Override
     public void logRouterInfo() {
-        logger.info("DummyRouter " + getName());
+        logger.info("DummyRouter {}", getName());
     }
 
     @Override