Minor style fixes / close es client explicitly.

Author: Robin Duda

core/main/java/com/codingchili/core/configuration/CoreStrings.java

@@ -137,6 +137,7 @@ public abstract class CoreStrings {
     public static final String ID_OPTIONS = "options";
     public static final String ID_HANDLER = "handler";
     public static final String ID_UNDEFINED = "undefined";
+    public static final String ID_STATISTICS = "statistics";
 
     // Storage constants
     public static final String DEFAULT_DB = "db";

core/main/java/com/codingchili/core/protocol/Protocol.java

@@ -1,6 +1,5 @@
 package com.codingchili.core.protocol;
 
-import com.codingchili.core.context.CoreRuntimeException;
 import io.vertx.core.Future;
 import io.vertx.core.buffer.Buffer;
 
@@ -44,7 +43,7 @@ public class Protocol<RequestType> {
     private Function<Request, String> routeMapper = Request::route;
     private boolean emitDocumentation = false;
     private Route<RequestType> lastAddedRoute;
-    private AtomicBoolean dirty = new AtomicBoolean(true);
+    private final AtomicBoolean dirty = new AtomicBoolean(true);
     private Class<?> dataModel;
     private Logger logger = new ConsoleLogger(getClass());
     private String target = "";

core/main/java/com/codingchili/core/protocol/RoleMap.java

@@ -15,7 +15,7 @@ public class RoleMap {
     public static final String USER = "user";
     public static final String PUBLIC = "public";
     public static final String UNSET = "unset";
-    private static Map<String, RoleType> roleMap = new HashMap<>();
+    private static final Map<String, RoleType> roleMap = new HashMap<>();
 
     static {
         put(ADMIN, Role.ADMIN);

core/main/java/com/codingchili/core/storage/ElasticMap.java

@@ -30,6 +30,7 @@
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
+import com.codingchili.core.context.ShutdownListener;
 import com.codingchili.core.context.StorageContext;
 import com.codingchili.core.protocol.Serializer;
 import com.codingchili.core.security.Validator;
@@ -54,7 +55,6 @@ public class ElasticMap<Value extends Storable> implements AsyncStorage<Value> {
     public ElasticMap(Promise<AsyncStorage<Value>> promise, StorageContext<Value> context) {
         this.context = context;
         this.index = constructIndexName(context);
-
         try {
             client = new RestHighLevelClient(
                     RestClient.builder(
@@ -64,7 +64,13 @@ public ElasticMap(Promise<AsyncStorage<Value>> promise, StorageContext<Value> co
                 if (done.succeeded()) {
                     promise.complete(ElasticMap.this);
                 } else {
-                    promise.fail(done.cause());
+                    try {
+                        this.client.close();
+                    } catch (Throwable ignored) {
+
+                    } finally {
+                        promise.fail(done.cause());
+                    }
                 }
             });
         } catch (Throwable e) {