0.5 use optionals

ocpp-common/pom.xml

@@ -35,6 +35,20 @@
      </scm>
 
     <dependencies>
+
+        <!-- Logging -->
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-api</artifactId>
+            <version>1.7.25</version>
+        </dependency>
+        <dependency>
+            <groupId>ch.qos.logback</groupId>
+            <artifactId>logback-classic</artifactId>
+            <version>1.2.3</version>
+        </dependency>
+
+        <!-- Tests -->
         <dependency>
             <groupId>junit</groupId>
             <artifactId>junit</artifactId>
@@ -53,16 +67,6 @@
             <version>1.3</version>
             <scope>test</scope>
         </dependency>
-        <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-api</artifactId>
-            <version>2.10.0</version>
-        </dependency>
-        <dependency>
-            <groupId>org.apache.logging.log4j</groupId>
-            <artifactId>log4j-core</artifactId>
-            <version>2.10.0</version>
-        </dependency>
     </dependencies>
     <build>
         <plugins>

ocpp-common/src/main/java/eu/chargetime/ocpp/Client.java

@@ -29,8 +29,10 @@ of this software and associated documentation files (the "Software"), to deal
 import eu.chargetime.ocpp.feature.Feature;
 import eu.chargetime.ocpp.model.Confirmation;
 import eu.chargetime.ocpp.model.Request;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 /**
@@ -43,7 +45,7 @@ of this software and associated documentation files (the "Software"), to deal
  */
 public class Client
 {
-    private static final org.apache.logging.log4j.Logger logger = LogManager.getLogger(Client.class);
+    private static final Logger logger = LoggerFactory.getLogger(Client.class);
 
     private Session session;
     private final IFeatureRepository featureRepository;
@@ -73,25 +75,33 @@ public void connect(String uri, ClientEvents events)
 
             @Override
             public void handleConfirmation(String uniqueId, Confirmation confirmation) {
-                CompletableFuture<Confirmation> promise = promiseRepository.getPromise(uniqueId);
-                if (promise != null) {
-                    promise.complete(confirmation);
+                Optional<CompletableFuture<Confirmation>> promiseOptional = promiseRepository.getPromise(uniqueId);
+                if (promiseOptional.isPresent()) {
+                    promiseOptional.get().complete(confirmation);
                     promiseRepository.removePromise(uniqueId);
+                } else {
+                    logger.debug("Promise not found for confirmation {}", confirmation);
                 }
             }
 
             @Override
-            public Confirmation handleRequest(Request request) {
-                Feature feature = featureRepository.findFeature(request);
-                return feature.handleRequest(null, request);
+            public Confirmation handleRequest(Request request) throws UnsupportedFeatureException {
+                Optional<Feature> featureOptional = featureRepository.findFeature(request);
+                if(featureOptional.isPresent()) {
+                    return featureOptional.get().handleRequest(null, request);
+                } else {
+                    throw new UnsupportedFeatureException();
+                }
             }
 
             @Override
             public void handleError(String uniqueId, String errorCode, String errorDescription, Object payload) {
-                CompletableFuture<Confirmation> promise = promiseRepository.getPromise(uniqueId);
-                if (promise != null) {
-                    promise.completeExceptionally(new CallErrorException(errorCode, errorCode, payload));
+                Optional<CompletableFuture<Confirmation>> promiseOptional = promiseRepository.getPromise(uniqueId);
+                if (promiseOptional.isPresent()) {
+                    promiseOptional.get().completeExceptionally(new CallErrorException(errorCode, errorCode, payload));
                     promiseRepository.removePromise(uniqueId);
+                } else {
+                    logger.debug("Promise not found for error {}", errorDescription);
                 }
             }
 
@@ -132,16 +142,17 @@ public void disconnect()
      * @see                                     CompletableFuture
      */
     public CompletableFuture<Confirmation> send(Request request) throws UnsupportedFeatureException, OccurenceConstraintException {
-        Feature feature = featureRepository.findFeature(request);
-        if (feature == null)
+        Optional<Feature> featureOptional = featureRepository.findFeature(request);
+        if (!featureOptional.isPresent())
             throw new UnsupportedFeatureException();
 
         if (!request.validate())
             throw new OccurenceConstraintException();
 
         String id = session.storeRequest(request);
         CompletableFuture<Confirmation> promise = promiseRepository.createPromise(id);
-        session.sendRequest(feature.getAction(), request, id);
+
+        session.sendRequest(featureOptional.get().getAction(), request, id);
         return promise;
     }
 }

ocpp-common/src/main/java/eu/chargetime/ocpp/Communicator.java

@@ -1,7 +1,8 @@
 package eu.chargetime.ocpp;
 
 import eu.chargetime.ocpp.model.*;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.ArrayDeque;
 
@@ -43,7 +44,7 @@ of this software and associated documentation files (the "Software"), to deal
  * Must be overloaded to implement a specific format.
  */
 public abstract class Communicator {
-    private static final org.apache.logging.log4j.Logger logger = LogManager.getLogger(Communicator.class);
+    private static final Logger logger = LoggerFactory.getLogger(Communicator.class);
 
 	private RetryRunner retryRunner;
     protected Radio radio;

ocpp-common/src/main/java/eu/chargetime/ocpp/FeatureRepository.java

@@ -32,6 +32,7 @@ of this software and associated documentation files (the "Software"), to deal
 
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Optional;
 
 public class FeatureRepository implements IFeatureRepository {
 
@@ -62,19 +63,16 @@ public void addFeatureProfile(Profile profile) {
      * Anything else will return null.
      *
      * @param needle Object supports {@link String}, {@link Request} or {@link Confirmation}
-     * @return Instance of the supported Feature
+     * @return Optional of instance of the supported Feature
      */
-    public Feature findFeature(Object needle) {
-        Feature output = null;
-
+    public Optional<Feature> findFeature(Object needle) {
         for (Feature feature : featureList) {
             if (featureContains(feature, needle)) {
-                output = feature;
-                break;
+                return Optional.of(feature);
             }
         }
 
-        return output;
+        return Optional.empty();
     }
 
     /**

ocpp-common/src/main/java/eu/chargetime/ocpp/IFeatureRepository.java

@@ -28,8 +28,10 @@ of this software and associated documentation files (the "Software"), to deal
 import eu.chargetime.ocpp.feature.Feature;
 import eu.chargetime.ocpp.feature.profile.Profile;
 
+import java.util.Optional;
+
 public interface IFeatureRepository {
     void addFeatureProfile(Profile profile);
 
-    Feature findFeature(Object needle);
+    Optional<Feature> findFeature(Object needle);
 }

ocpp-common/src/main/java/eu/chargetime/ocpp/IPromiseRepository.java

@@ -27,12 +27,13 @@ of this software and associated documentation files (the "Software"), to deal
 
 import eu.chargetime.ocpp.model.Confirmation;
 
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 public interface IPromiseRepository {
     CompletableFuture<Confirmation> createPromise(String uniqueId);
 
-    CompletableFuture<Confirmation> getPromise(String uniqueId);
+    Optional<CompletableFuture<Confirmation>> getPromise(String uniqueId);
 
     void removePromise(String uniqueId);
 }

ocpp-common/src/main/java/eu/chargetime/ocpp/PromiseRepository.java

@@ -3,7 +3,9 @@
 import eu.chargetime.ocpp.model.Confirmation;
 import eu.chargetime.ocpp.model.Request;
 
+
 import java.util.HashMap;
+import java.util.Optional;
 import java.util.concurrent.CompletableFuture;
 
 /*
@@ -55,10 +57,10 @@ public CompletableFuture<Confirmation> createPromise(String uniqueId) {
      * Get stored call back {@link CompletableFuture}.
      *
      * @param uniqueId identification for the {@link Request}
-     * @return call back {@link CompletableFuture}
+     * @return optional of call back {@link CompletableFuture}
      */
-    public CompletableFuture<Confirmation> getPromise(String uniqueId) {
-        return promises.get(uniqueId);
+    public Optional<CompletableFuture<Confirmation>> getPromise(String uniqueId) {
+        return Optional.ofNullable(promises.get(uniqueId));
     }
 
     /**

ocpp-common/src/main/java/eu/chargetime/ocpp/Queue.java

@@ -1,9 +1,11 @@
 package eu.chargetime.ocpp;
 
 import eu.chargetime.ocpp.model.Request;
-import org.apache.logging.log4j.LogManager;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 import java.util.HashMap;
+import java.util.Optional;
 import java.util.UUID;
 
 /*
@@ -38,7 +40,7 @@ of this software and associated documentation files (the "Software"), to deal
  */
 public class Queue
 {
-	private static final org.apache.logging.log4j.Logger logger = LogManager.getLogger(Queue.class);
+	private static final Logger logger = LoggerFactory.getLogger(Queue.class);
 
 	private HashMap<String, Request> requestQueue;
 
@@ -55,27 +57,32 @@ public Queue () {
     public String store(Request request) {
         String ticket = UUID.randomUUID().toString();
         requestQueue.put(ticket, request);
+
+        logger.debug("Queue size: {}", requestQueue.size());
+
         return ticket;
     }
 
     /**
      * Restore a {@link Request} using a unique identifier.
      * The identifier can only be used once.
      * If no Request was found, null is returned.
-     * 
-     * FIXME: use optional instead
      *
      * @param ticket    unique identifier returned when {@link Request} was initially stored.
-     * @return the stored {@link Request}
+     * @return the optional with stored {@link Request}
      */
-    public Request restoreRequest(String ticket) {
-        Request request = null;
+    public Optional<Request> restoreRequest(String ticket) {
+
         try {
-            request = requestQueue.get(ticket);
+            Request request = requestQueue.get(ticket);
             requestQueue.remove(ticket);
+
+            logger.debug("Queue size: {}", requestQueue.size());
+
+            return Optional.ofNullable(request);
         } catch (Exception ex) {
             logger.warn("restoreRequest({}) failed", ticket, ex);
         }
-        return request;
+        return Optional.empty();
     }
 }