refactor: merge ChargePointHelperService into ChargePointService

problem during the refactor: spring boot app did not want to start due to cyclic dependencies

   ocppConfiguration
┌─────┐
|  centralSystemService12_SoapServer
↑     ↓
|  centralSystemService16_Service
↑     ↓
|  chargePointService
↑     ↓
|  ocpp12WebSocketEndpoint
└─────┘

chargePointService was injecting ocpp12WebSocketEndpoint (and other versions variants of it) to get the data out of its internal sessionContextStore.
in order to break the cycle, i had to create a standalone SessionContextStoreHolder which creates and holds references to sessionContextStore instances.
there are, then, provided to WebSocketEndpoint instances but also to ChargePointService

(also related to issue #1831)

Author: goekay

src/main/java/de/rwth/idsg/steve/ocpp/ws/AbstractWebSocketEndpoint.java

@@ -19,12 +19,10 @@
 package de.rwth.idsg.steve.ocpp.ws;
 
 import com.google.common.base.Strings;
-import de.rwth.idsg.steve.config.SteveProperties;
 import de.rwth.idsg.steve.config.WebSocketConfiguration;
 import de.rwth.idsg.steve.ocpp.OcppTransport;
 import de.rwth.idsg.steve.ocpp.OcppVersion;
 import de.rwth.idsg.steve.ocpp.ws.data.CommunicationContext;
-import de.rwth.idsg.steve.ocpp.ws.data.SessionContext;
 import de.rwth.idsg.steve.ocpp.ws.pipeline.Deserializer;
 import de.rwth.idsg.steve.ocpp.ws.pipeline.IncomingPipeline;
 import de.rwth.idsg.steve.ocpp.ws.pipeline.OcppCallHandler;
@@ -47,9 +45,7 @@
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.Collections;
-import java.util.Deque;
 import java.util.List;
-import java.util.Map;
 import java.util.concurrent.ScheduledFuture;
 import java.util.function.Consumer;
 
@@ -76,13 +72,13 @@ public AbstractWebSocketEndpoint(TaskScheduler taskScheduler,
                                      OcppServerRepository ocppServerRepository,
                                      FutureResponseContextStore futureResponseContextStore,
                                      ApplicationEventPublisher applicationEventPublisher,
-                                     SteveProperties steveProperties,
+                                     SessionContextStoreHolder sessionContextStoreHolder,
                                      AbstractTypeStore typeStore) {
         this.taskScheduler = taskScheduler;
         this.ocppServerRepository = ocppServerRepository;
         this.futureResponseContextStore = futureResponseContextStore;
         this.pipeline = new IncomingPipeline(new Deserializer(futureResponseContextStore, typeStore), this);
-        this.sessionContextStore = new SessionContextStoreImpl(steveProperties.getOcpp().getWsSessionSelectStrategy());
+        this.sessionContextStore = sessionContextStoreHolder.getOrCreate(getVersion());
 
         connectedCallbackList.add((chargeBoxId) -> applicationEventPublisher.publishEvent(new OcppStationWebSocketConnected(chargeBoxId)));
         disconnectedCallbackList.add((chargeBoxId) -> applicationEventPublisher.publishEvent(new OcppStationWebSocketDisconnected(chargeBoxId)));
@@ -210,28 +206,4 @@ protected String getChargeBoxId(WebSocketSession session) {
         return (String) session.getAttributes().get(CHARGEBOX_ID_KEY);
     }
 
-    protected void registerConnectedCallback(Consumer<String> consumer) {
-        connectedCallbackList.add(consumer);
-    }
-
-    protected void registerDisconnectedCallback(Consumer<String> consumer) {
-        disconnectedCallbackList.add(consumer);
-    }
-
-    public List<String> getChargeBoxIdList() {
-        return sessionContextStore.getChargeBoxIdList();
-    }
-
-    public int getNumberOfChargeBoxes() {
-        return sessionContextStore.getNumberOfChargeBoxes();
-    }
-
-    public Map<String, Deque<SessionContext>> getACopy() {
-        return sessionContextStore.getACopy();
-    }
-
-    public WebSocketSession getSession(String chargeBoxId) {
-        return sessionContextStore.getSession(chargeBoxId);
-    }
-
 }

src/main/java/de/rwth/idsg/steve/ocpp/ws/ChargePointServiceJsonInvoker.java

@@ -26,11 +26,8 @@
 import de.rwth.idsg.steve.ocpp.ws.data.FutureResponseContext;
 import de.rwth.idsg.steve.ocpp.ws.data.OcppJsonCall;
 import de.rwth.idsg.steve.ocpp.ws.ocpp12.Ocpp12TypeStore;
-import de.rwth.idsg.steve.ocpp.ws.ocpp12.Ocpp12WebSocketEndpoint;
 import de.rwth.idsg.steve.ocpp.ws.ocpp15.Ocpp15TypeStore;
-import de.rwth.idsg.steve.ocpp.ws.ocpp15.Ocpp15WebSocketEndpoint;
 import de.rwth.idsg.steve.ocpp.ws.ocpp16.Ocpp16TypeStore;
-import de.rwth.idsg.steve.ocpp.ws.ocpp16.Ocpp16WebSocketEndpoint;
 import de.rwth.idsg.steve.ocpp.ws.pipeline.OutgoingCallPipeline;
 import de.rwth.idsg.steve.repository.dto.ChargePointSelect;
 import lombok.RequiredArgsConstructor;
@@ -49,10 +46,7 @@
 public class ChargePointServiceJsonInvoker {
 
     private final OutgoingCallPipeline outgoingCallPipeline;
-
-    private final Ocpp12WebSocketEndpoint ocpp12WebSocketEndpoint;
-    private final Ocpp15WebSocketEndpoint ocpp15WebSocketEndpoint;
-    private final Ocpp16WebSocketEndpoint ocpp16WebSocketEndpoint;
+    private final SessionContextStoreHolder sessionContextStoreHolder;
 
     /**
      * Just a wrapper to make try-catch block and exception handling stand out
@@ -73,11 +67,7 @@ public void runPipeline(ChargePointSelect cps, CommunicationTask task) {
     private void run(ChargePointSelect cps, CommunicationTask task) {
         var chargeBoxId = cps.getChargeBoxId();
 
-        var endpoint = switch (cps.getOcppProtocol().getVersion()) {
-            case V_12 -> ocpp12WebSocketEndpoint;
-            case V_15 -> ocpp15WebSocketEndpoint;
-            case V_16 -> ocpp16WebSocketEndpoint;
-        };
+        var sessionStore = sessionContextStoreHolder.getOrCreate(cps.getOcppProtocol().getVersion());
 
         var typeStore = switch (cps.getOcppProtocol().getVersion()) {
             case V_12 -> Ocpp12TypeStore.INSTANCE;
@@ -103,7 +93,7 @@ private void run(ChargePointSelect cps, CommunicationTask task) {
 
         FutureResponseContext frc = new FutureResponseContext(task, pair.getResponseClass());
 
-        CommunicationContext context = new CommunicationContext(endpoint.getSession(chargeBoxId), chargeBoxId);
+        CommunicationContext context = new CommunicationContext(sessionStore.getSession(chargeBoxId), chargeBoxId);
         context.setOutgoingMessage(call);
         context.setFutureResponseContext(frc);
 

src/main/java/de/rwth/idsg/steve/ocpp/ws/SessionContextStoreHolder.java

@@ -0,0 +1,46 @@
+/*
+ * SteVe - SteckdosenVerwaltung - https://github.com/steve-community/steve
+ * Copyright (C) 2013-2025 SteVe Community Team
+ * All Rights Reserved.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+package de.rwth.idsg.steve.ocpp.ws;
+
+import de.rwth.idsg.steve.config.SteveProperties;
+import de.rwth.idsg.steve.ocpp.OcppVersion;
+import de.rwth.idsg.steve.ocpp.ws.custom.WsSessionSelectStrategy;
+import org.springframework.stereotype.Component;
+
+import java.util.EnumMap;
+
+/**
+ * @author Sevket Goekay <[email protected]>
+ * @since 29.10.2025
+ */
+@Component
+public class SessionContextStoreHolder {
+
+    private final EnumMap<OcppVersion, SessionContextStore> storesPerVersion = new EnumMap<>(OcppVersion.class);
+
+    private final WsSessionSelectStrategy wsSessionSelectStrategy;
+
+    public SessionContextStoreHolder(SteveProperties steveProperties) {
+        wsSessionSelectStrategy = steveProperties.getOcpp().getWsSessionSelectStrategy();
+    }
+
+    public SessionContextStore getOrCreate(OcppVersion version) {
+        return storesPerVersion.computeIfAbsent(version, k -> new SessionContextStoreImpl(wsSessionSelectStrategy));
+    }
+}

src/main/java/de/rwth/idsg/steve/ocpp/ws/ocpp12/Ocpp12WebSocketEndpoint.java

@@ -20,12 +20,12 @@
 
 import de.rwth.idsg.ocpp.jaxb.RequestType;
 import de.rwth.idsg.ocpp.jaxb.ResponseType;
-import de.rwth.idsg.steve.config.SteveProperties;
 import de.rwth.idsg.steve.ocpp.OcppProtocol;
 import de.rwth.idsg.steve.ocpp.OcppVersion;
 import de.rwth.idsg.steve.ocpp.soap.CentralSystemService12_SoapServer;
 import de.rwth.idsg.steve.ocpp.ws.AbstractWebSocketEndpoint;
 import de.rwth.idsg.steve.ocpp.ws.FutureResponseContextStore;
+import de.rwth.idsg.steve.ocpp.ws.SessionContextStoreHolder;
 import de.rwth.idsg.steve.repository.OcppServerRepository;
 import ocpp.cs._2010._08.AuthorizeRequest;
 import ocpp.cs._2010._08.BootNotificationRequest;
@@ -54,8 +54,8 @@ public Ocpp12WebSocketEndpoint(TaskScheduler taskScheduler,
                                    FutureResponseContextStore futureResponseContextStore,
                                    ApplicationEventPublisher applicationEventPublisher,
                                    CentralSystemService12_SoapServer server,
-                                   SteveProperties steveProperties) {
-        super(taskScheduler, ocppServerRepository, futureResponseContextStore, applicationEventPublisher, steveProperties, Ocpp12TypeStore.INSTANCE);
+                                   SessionContextStoreHolder sessionContextStoreHolder) {
+        super(taskScheduler, ocppServerRepository, futureResponseContextStore, applicationEventPublisher, sessionContextStoreHolder, Ocpp12TypeStore.INSTANCE);
         this.server = server;
     }
 

src/main/java/de/rwth/idsg/steve/ocpp/ws/ocpp15/Ocpp15WebSocketEndpoint.java

@@ -20,12 +20,12 @@
 
 import de.rwth.idsg.ocpp.jaxb.RequestType;
 import de.rwth.idsg.ocpp.jaxb.ResponseType;
-import de.rwth.idsg.steve.config.SteveProperties;
 import de.rwth.idsg.steve.ocpp.OcppProtocol;
 import de.rwth.idsg.steve.ocpp.OcppVersion;
 import de.rwth.idsg.steve.ocpp.soap.CentralSystemService15_SoapServer;
 import de.rwth.idsg.steve.ocpp.ws.AbstractWebSocketEndpoint;
 import de.rwth.idsg.steve.ocpp.ws.FutureResponseContextStore;
+import de.rwth.idsg.steve.ocpp.ws.SessionContextStoreHolder;
 import de.rwth.idsg.steve.repository.OcppServerRepository;
 import ocpp.cs._2012._06.AuthorizeRequest;
 import ocpp.cs._2012._06.BootNotificationRequest;
@@ -55,8 +55,8 @@ public Ocpp15WebSocketEndpoint(TaskScheduler taskScheduler,
                                    FutureResponseContextStore futureResponseContextStore,
                                    ApplicationEventPublisher applicationEventPublisher,
                                    CentralSystemService15_SoapServer server,
-                                   SteveProperties steveProperties) {
-        super(taskScheduler, ocppServerRepository, futureResponseContextStore, applicationEventPublisher, steveProperties, Ocpp15TypeStore.INSTANCE);
+                                   SessionContextStoreHolder sessionContextStoreHolder) {
+        super(taskScheduler, ocppServerRepository, futureResponseContextStore, applicationEventPublisher, sessionContextStoreHolder, Ocpp15TypeStore.INSTANCE);
         this.server = server;
     }
 

src/main/java/de/rwth/idsg/steve/ocpp/ws/ocpp16/Ocpp16WebSocketEndpoint.java

@@ -20,12 +20,12 @@
 
 import de.rwth.idsg.ocpp.jaxb.RequestType;
 import de.rwth.idsg.ocpp.jaxb.ResponseType;
-import de.rwth.idsg.steve.config.SteveProperties;
 import de.rwth.idsg.steve.ocpp.OcppProtocol;
 import de.rwth.idsg.steve.ocpp.OcppVersion;
 import de.rwth.idsg.steve.ocpp.soap.CentralSystemService16_SoapServer;
 import de.rwth.idsg.steve.ocpp.ws.AbstractWebSocketEndpoint;
 import de.rwth.idsg.steve.ocpp.ws.FutureResponseContextStore;
+import de.rwth.idsg.steve.ocpp.ws.SessionContextStoreHolder;
 import de.rwth.idsg.steve.repository.OcppServerRepository;
 import ocpp.cs._2015._10.AuthorizeRequest;
 import ocpp.cs._2015._10.BootNotificationRequest;
@@ -55,8 +55,8 @@ public Ocpp16WebSocketEndpoint(TaskScheduler taskScheduler,
                                    FutureResponseContextStore futureResponseContextStore,
                                    ApplicationEventPublisher applicationEventPublisher,
                                    CentralSystemService16_SoapServer server,
-                                   SteveProperties steveProperties) {
-        super(taskScheduler, ocppServerRepository, futureResponseContextStore, applicationEventPublisher, steveProperties, Ocpp16TypeStore.INSTANCE);
+                                   SessionContextStoreHolder sessionContextStoreHolder) {
+        super(taskScheduler, ocppServerRepository, futureResponseContextStore, applicationEventPublisher, sessionContextStoreHolder, Ocpp16TypeStore.INSTANCE);
         this.server = server;
     }