fix pmd warnings

build.gradle

@@ -1,11 +1,9 @@
-import com.github.spotbugs.SpotBugsTask
-
 plugins {
     id 'org.springframework.boot' version '2.2.5.RELEASE'
     id 'io.spring.dependency-management' version '1.0.9.RELEASE'
     id 'java'
 
-    id 'com.github.spotbugs' version '3.0.0'
+    id 'com.github.spotbugs' version '4.0.1'
     id 'checkstyle'
     id 'pmd'
 }
@@ -14,30 +12,39 @@ group = 'mops'
 version = '0.0.1-SNAPSHOT'
 sourceCompatibility = '11'
 
+repositories {
+    maven {
+        url = 'https://s3.cs.hhu.de/public/mops/'
+        metadataSources {
+            artifact()
+        }
+    }
+    mavenCentral()
+}
+
 spotbugs {
+    toolVersion = '4.0.1'
     ignoreFailures = false
     reportLevel = "high"
     effort = "max"
-    toolVersion = '4.0.0-RC1'
+    showProgress = true
 }
 
-tasks.withType(SpotBugsTask) {
+spotbugsMain {
     reports {
-        xml.enabled = false
+        html {
-        html.enabled = true
+            enabled = true
+        }
     }
 }
 
 pmd {
     consoleOutput = true
     ignoreFailures = true
-    toolVersion = "6.21.0"
+    toolVersion = "6.22.0"
     rulePriority = 5
-    ruleSets = ["category/java/errorprone.xml",
+    ruleSetFiles = files("config/pmd/ruleset.xml")
-                "category/java/bestpractices.xml",
+    ruleSets = []
-                "category/java/security.xml",
-                "category/java/performance.xml",
-                "category/java/design.xml"]
 }
 
 checkstyle {
@@ -56,16 +63,6 @@ configurations {
     }
 }
 
-repositories {
-    maven {
-        url = 'https://s3.cs.hhu.de/public/mops/'
-        metadataSources {
-            artifact()
-        }
-    }
-    mavenCentral()
-}
-
 dependencies {
     implementation 'org.springframework.boot:spring-boot-starter-actuator'
     implementation 'org.springframework.boot:spring-boot-starter-data-jdbc'

config/pmd/ruleset.xml

@@ -19,7 +19,7 @@
     <rule ref="category/java/bestpractices.xml/ConstantsInInterface"/>
     <rule ref="category/java/bestpractices.xml/DefaultLabelNotLastInSwitchStmt"/>
     <rule ref="category/java/bestpractices.xml/ForLoopCanBeForeach"/>
-    <rule ref="category/java/bestpractices.xml/GuardLogStatement"/>
+<!--    <rule ref="category/java/bestpractices.xml/GuardLogStatement"/>-->
     <!-- <rule ref="category/java/bestpractices.xml/JUnit4SuitesShouldUseSuiteAnnotation" /> -->
     <!-- <rule ref="category/java/bestpractices.xml/JUnit4TestShouldUseAfterAnnotation" /> -->
     <!-- <rule ref="category/java/bestpractices.xml/JUnit4TestShouldUseBeforeAnnotation" /> -->
@@ -150,7 +150,7 @@
     <rule ref="category/java/design.xml/FinalFieldCouldBeStatic"/>
     <!-- <rule ref="category/java/design.xml/GodClass" /> -->
     <!-- <rule ref="category/java/design.xml/ImmutableField" /> -->
-    <rule ref="category/java/design.xml/LawOfDemeter"/>
+    <!--    <rule ref="category/java/design.xml/LawOfDemeter"/>-->
     <rule ref="category/java/design.xml/LogicInversion"/>
 
     <rule ref="category/java/design.xml/CyclomaticComplexity"/>
@@ -298,7 +298,7 @@
     <rule ref="category/java/multithreading.xml/DontCallThreadRun"/>
     <rule ref="category/java/multithreading.xml/DoubleCheckedLocking"/>
     <rule ref="category/java/multithreading.xml/NonThreadSafeSingleton"/>
-    <rule ref="category/java/multithreading.xml/UnsynchronizedStaticDateFormatter"/>
+    <!--    <rule ref="category/java/multithreading.xml/UnsynchronizedStaticDateFormatter"/>-->
     <!-- <rule ref="category/java/multithreading.xml/UseConcurrentHashMap" /> -->
     <rule ref="category/java/multithreading.xml/UseNotifyAllInsteadOfNotify"/>
 

gruppe.yml

@@ -1,20 +0,0 @@
-# Bei "schicht" können Sie 'vormittags', 'nachmittags' oder 'egal' eintragen.
-
-gruppe: IT-Bois
-url: https://github.com/hhu-propra2/abschlussprojekt-it-bois
-names:
-  - killerber4t
-  - tomvahl
-  - AndiBuls
-  - XXNitram
-  - LukasEttel
-  - Mahgs
-  - ChUrl
-  - kasch309
-notebook: true
-schicht: nachmittags
-projektauswahl:
-  - Gruppenbildung
-  - Punkteübersicht
-  - Materialsammlung
-  - Korrektorinnen Bewerbung

src/main/java/mops/gruppen2/aspect/LogAspect.java

@@ -55,7 +55,7 @@ public class LogAspect {
         joinPoint.proceed();
         long stop = System.currentTimeMillis();
 
-        log.trace("Ausführungsdauer: {} Millis", (stop - start));
+        log.trace("Ausführungsdauer: {} Millis", stop - start);
 
         return joinPoint.proceed();
     }

src/main/java/mops/gruppen2/aspect/annotation/Trace.java

@@ -6,7 +6,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Schreibt eine benutzerdefinierte Nachricht in den Trace-Stream bei Methodenaufruf
+ * Schreibt eine benutzerdefinierte Nachricht in den Trace-Stream bei Methodenaufruf.
  */
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)

src/main/java/mops/gruppen2/aspect/annotation/TraceExecutionTime.java

@@ -7,7 +7,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Schreibt die Methodenausführdauer in den Trace-Stream
+ * Schreibt die Methodenausführdauer in den Trace-Stream.
  */
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)

src/main/java/mops/gruppen2/aspect/annotation/TraceMethodCall.java

@@ -6,7 +6,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Schreibt eine Nachricht bei Methodenausführung in den Trace-Stream
+ * Schreibt eine Nachricht bei Methodenausführung in den Trace-Stream.
  */
 @Target(ElementType.METHOD)
 @Retention(RetentionPolicy.RUNTIME)

src/main/java/mops/gruppen2/aspect/annotation/TraceMethodCalls.java

@@ -6,7 +6,7 @@ import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
 /**
- * Schreibt eine Nachricht für jede ausgeführte Methode einer Klasse in den Trace-Stream
+ * Schreibt eine Nachricht für jede ausgeführte Methode einer Klasse in den Trace-Stream.
  */
 @Target(ElementType.TYPE)
 @Retention(RetentionPolicy.RUNTIME)

src/main/java/mops/gruppen2/domain/helper/APIHelper.java

@@ -1,17 +1,15 @@
-package mops.gruppen2.domain.service;
+package mops.gruppen2.domain.helper;
 
 import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.web.api.GroupRequestWrapper;
-import org.springframework.stereotype.Service;
 
 import java.util.List;
 
-@Service
 @Log4j2
-public class APIService {
+public final class APIHelper {
 
-    private APIService() {}
+    private APIHelper() {}
 
     public static GroupRequestWrapper wrap(long status, List<Group> groupList) {
         return new GroupRequestWrapper(status, groupList);

src/main/java/mops/gruppen2/domain/helper/CsvHelper.java

@@ -1,4 +1,4 @@
-package mops.gruppen2.domain.service;
+package mops.gruppen2.domain.helper;
 
 import com.fasterxml.jackson.databind.ObjectReader;
 import com.fasterxml.jackson.dataformat.csv.CsvMapper;
@@ -7,7 +7,6 @@ import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.exception.EventException;
 import mops.gruppen2.domain.exception.WrongFileException;
-import org.springframework.stereotype.Service;
 import org.springframework.web.multipart.MultipartFile;
 
 import java.io.IOException;
@@ -16,11 +15,10 @@ import java.util.Collections;
 import java.util.List;
 import java.util.stream.Collectors;
 
-@Service
 @Log4j2
-public final class CsvService {
+public final class CsvHelper {
 
-    private CsvService() {}
+    private CsvHelper() {}
 
     public static List<User> readCsvFile(MultipartFile file) throws EventException {
         if (file == null || file.isEmpty()) {

src/main/java/mops/gruppen2/domain/helper/IdHelper.java

@@ -1,21 +1,19 @@
-package mops.gruppen2.domain.service;
+package mops.gruppen2.domain.helper;
 
 import lombok.extern.log4j.Log4j2;
-import org.springframework.stereotype.Service;
 
 import java.util.List;
 import java.util.UUID;
 import java.util.stream.Collectors;
 
-@Service
 @Log4j2
-public final class IdService {
+public final class IdHelper {
 
-    private IdService() {}
+    private IdHelper() {}
 
     public static List<UUID> stringsToUUID(List<String> groupIds) {
         return groupIds.stream()
-                       .map(IdService::stringToUUID)
+                       .map(IdHelper::stringToUUID)
                        .collect(Collectors.toList());
     }
 

src/main/java/mops/gruppen2/domain/helper/JsonHelper.java

@@ -1,19 +1,17 @@
-package mops.gruppen2.domain.service;
+package mops.gruppen2.domain.helper;
 
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.domain.event.Event;
-import org.springframework.stereotype.Service;
 
 /**
  * Übersetzt JSON-Event-Payloads zu Java-Event-Repräsentationen und zurück.
  */
-@Service
 @Log4j2
-public final class JsonService {
+public final class JsonHelper {
 
-    private JsonService() {}
+    private JsonHelper() {}
 
     /**
      * Übersetzt eine Java-Event-Repräsentation zu einem JSON-Event-Payload.
@@ -25,7 +23,7 @@ public final class JsonService {
      * @throws JsonProcessingException Bei JSON Fehler
      */
 
-    static String serializeEvent(Event event) throws JsonProcessingException {
+    public static String serializeEvent(Event event) throws JsonProcessingException {
         ObjectMapper mapper = new ObjectMapper();
         return mapper.writeValueAsString(event);
     }
@@ -39,7 +37,7 @@ public final class JsonService {
      *
      * @throws JsonProcessingException Bei JSON Fehler
      */
-    static Event deserializeEvent(String json) throws JsonProcessingException {
+    public static Event deserializeEvent(String json) throws JsonProcessingException {
         ObjectMapper mapper = new ObjectMapper();
         return mapper.readValue(json, Event.class);
     }

src/main/java/mops/gruppen2/domain/helper/ValidationHelper.java

@@ -1,4 +1,4 @@
-package mops.gruppen2.domain.service;
+package mops.gruppen2.domain.helper;
 
 import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.domain.Group;
@@ -12,15 +12,13 @@ import mops.gruppen2.domain.exception.UserAlreadyExistsException;
 import mops.gruppen2.domain.exception.UserNotFoundException;
 import mops.gruppen2.web.form.CreateForm;
 import org.keycloak.adapters.springsecurity.token.KeycloakAuthenticationToken;
-import org.springframework.stereotype.Service;
 
 import static mops.gruppen2.domain.Role.ADMIN;
 
-@Service
 @Log4j2
-public final class ValidationService {
+public final class ValidationHelper {
 
-    private ValidationService() {}
+    private ValidationHelper() {}
 
 
     // ######################################## CHECK ############################################

src/main/java/mops/gruppen2/domain/service/EventStoreService.java

@@ -7,6 +7,8 @@ import mops.gruppen2.domain.event.AddUserEvent;
 import mops.gruppen2.domain.event.CreateGroupEvent;
 import mops.gruppen2.domain.event.Event;
 import mops.gruppen2.domain.exception.BadPayloadException;
+import mops.gruppen2.domain.helper.IdHelper;
+import mops.gruppen2.domain.helper.JsonHelper;
 import mops.gruppen2.persistance.EventRepository;
 import mops.gruppen2.persistance.dto.EventDTO;
 import org.springframework.stereotype.Service;
@@ -80,7 +82,7 @@ public class EventStoreService {
      */
     static EventDTO getDTOFromEvent(Event event) {
         try {
-            String payload = JsonService.serializeEvent(event);
+            String payload = JsonHelper.serializeEvent(event);
             return new EventDTO(null,
                                 event.getGroupId().toString(),
                                 event.getUserId(),
@@ -107,7 +109,7 @@ public class EventStoreService {
 
     private static Event getEventFromDTO(EventDTO dto) {
         try {
-            return JsonService.deserializeEvent(dto.getEvent_payload());
+            return JsonHelper.deserializeEvent(dto.getEvent_payload());
         } catch (JsonProcessingException e) {
             log.error("Payload {} konnte nicht deserialisiert werden!", dto.getEvent_payload(), e);
             throw new BadPayloadException(EventStoreService.class.toString());
@@ -231,7 +233,7 @@ public class EventStoreService {
 
     List<Event> findEventsByGroupAndType(List<UUID> groupIds, String... types) {
         return getEventsFromDTOs(eventStore.findEventDTOsByGroupAndType(Arrays.asList(types),
-                                                                        IdService.uuidsToString(groupIds)));
+                                                                        IdHelper.uuidsToString(groupIds)));
     }
 
     /**

src/main/java/mops/gruppen2/domain/service/GroupService.java

@@ -15,6 +15,7 @@ import mops.gruppen2.domain.event.UpdateGroupTitleEvent;
 import mops.gruppen2.domain.event.UpdateRoleEvent;
 import mops.gruppen2.domain.event.UpdateUserLimitEvent;
 import mops.gruppen2.domain.exception.EventException;
+import mops.gruppen2.domain.helper.ValidationHelper;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -115,8 +116,8 @@ public class GroupService {
      * @throws EventException Falls der User nicht gefunden wird
      */
     public void toggleMemberRole(User user, Group group) throws EventException {
-        ValidationService.throwIfNoMember(group, user);
+        ValidationHelper.throwIfNoMember(group, user);
-        ValidationService.throwIfLastAdmin(user, group);
+        ValidationHelper.throwIfLastAdmin(user, group);
 
         Role role = group.getRoles().get(user.getId());
         updateRole(user, group, role.toggle());
@@ -148,8 +149,8 @@ public class GroupService {
      * Prüft, ob der Nutzer schon Mitglied ist und ob Gruppe voll ist.
      */
     public void addUser(User user, Group group) {
-        ValidationService.throwIfMember(group, user);
+        ValidationHelper.throwIfMember(group, user);
-        ValidationService.throwIfGroupFull(group);
+        ValidationHelper.throwIfGroupFull(group);
 
         Event event = new AddUserEvent(group, user);
         event.apply(group);
@@ -173,10 +174,10 @@ public class GroupService {
      * Prüft, ob der Nutzer Mitglied ist und ob er der letzte Admin ist.
      */
     public void deleteUser(User user, Group group) throws EventException {
-        ValidationService.throwIfNoMember(group, user);
+        ValidationHelper.throwIfNoMember(group, user);
-        ValidationService.throwIfLastAdmin(user, group);
+        ValidationHelper.throwIfLastAdmin(user, group);
 
-        if (ValidationService.checkIfGroupEmpty(group)) {
+        if (ValidationHelper.checkIfGroupEmpty(group)) {
             deleteGroup(user, group);
         } else {
             Event event = new DeleteUserEvent(group, user);
@@ -191,7 +192,7 @@ public class GroupService {
      * Prüft, ob der Nutzer Admin ist.
      */
     public void deleteGroup(User user, Group group) {
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         Event event = new DeleteGroupEvent(group, user);
         event.apply(group);
@@ -206,7 +207,7 @@ public class GroupService {
      * Bei keiner Änderung wird nichts erzeugt.
      */
     public void updateTitle(User user, Group group, String title) {
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         if (title.trim().equals(group.getTitle())) {
             return;
@@ -224,7 +225,7 @@ public class GroupService {
      * Bei keiner Änderung wird nichts erzeugt.
      */
     public void updateDescription(User user, Group group, String description) {
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         if (description.trim().equals(group.getDescription())) {
             return;
@@ -242,7 +243,7 @@ public class GroupService {
      * Bei keiner Änderung wird nichts erzeugt.
      */
     private void updateRole(User user, Group group, Role role) {
-        ValidationService.throwIfNoMember(group, user);
+        ValidationHelper.throwIfNoMember(group, user);
 
         if (role == group.getRoles().get(user.getId())) {
             return;
@@ -260,7 +261,7 @@ public class GroupService {
      * Bei keiner Änderung wird nichts erzeugt.
      */
     public void updateUserLimit(User user, Group group, long userLimit) {
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         if (userLimit == group.getUserLimit()) {
             return;

src/main/java/mops/gruppen2/domain/service/ProjectionService.java

@@ -7,6 +7,7 @@ import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.event.Event;
 import mops.gruppen2.domain.exception.EventException;
 import mops.gruppen2.domain.exception.GroupNotFoundException;
+import mops.gruppen2.domain.helper.IdHelper;
 import org.springframework.cache.annotation.Cacheable;
 import org.springframework.stereotype.Service;
 
@@ -185,7 +186,7 @@ public class ProjectionService {
      * @throws GroupNotFoundException Wenn die Gruppe nicht gefunden wird
      */
     public Group projectSingleGroup(UUID groupId) throws GroupNotFoundException {
-        if (IdService.isEmpty(groupId)) {
+        if (IdHelper.isEmpty(groupId)) {
             throw new GroupNotFoundException(groupId + ": " + ProjectionService.class);
         }
 
@@ -202,7 +203,7 @@ public class ProjectionService {
      * Projiziert eine einzelne Gruppe, welche leer sein darf.
      */
     public Group projectParent(UUID parentId) {
-        if (IdService.isEmpty(parentId)) {
+        if (IdHelper.isEmpty(parentId)) {
             return new Group();
         }
 

src/main/java/mops/gruppen2/web/APIController.java

@@ -7,9 +7,9 @@ import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.aspect.annotation.TraceMethodCalls;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.User;
-import mops.gruppen2.domain.service.APIService;
+import mops.gruppen2.domain.helper.APIHelper;
+import mops.gruppen2.domain.helper.IdHelper;
 import mops.gruppen2.domain.service.EventStoreService;
-import mops.gruppen2.domain.service.IdService;
 import mops.gruppen2.domain.service.ProjectionService;
 import mops.gruppen2.web.api.GroupRequestWrapper;
 import org.springframework.security.access.annotation.Secured;
@@ -50,8 +50,8 @@ public class APIController {
     public GroupRequestWrapper getApiUpdate(@ApiParam("Letzte gespeicherte EventId des Anfragestellers")
                                             @PathVariable("id") long eventId) {
 
-        return APIService.wrap(eventStoreService.findMaxEventId(),
+        return APIHelper.wrap(eventStoreService.findMaxEventId(),
-                               projectionService.projectNewGroups(eventId));
+                              projectionService.projectNewGroups(eventId));
     }
 
     /**
@@ -63,7 +63,7 @@ public class APIController {
     public List<String> getApiUserGroups(@ApiParam("Nutzer-Id")
                                          @PathVariable("id") String userId) {
 
-        return IdService.uuidsToString(eventStoreService.findExistingUserGroups(new User(userId)));
+        return IdHelper.uuidsToString(eventStoreService.findExistingUserGroups(new User(userId)));
     }
 
     /**

src/main/java/mops/gruppen2/web/GroupCreationController.java

@@ -4,11 +4,11 @@ import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.aspect.annotation.TraceMethodCalls;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.User;
-import mops.gruppen2.domain.service.CsvService;
+import mops.gruppen2.domain.helper.CsvHelper;
+import mops.gruppen2.domain.helper.IdHelper;
+import mops.gruppen2.domain.helper.ValidationHelper;
 import mops.gruppen2.domain.service.GroupService;
-import mops.gruppen2.domain.service.IdService;
 import mops.gruppen2.domain.service.ProjectionService;
-import mops.gruppen2.domain.service.ValidationService;
 import mops.gruppen2.web.form.CreateForm;
 import mops.gruppen2.web.form.MetaForm;
 import mops.gruppen2.web.form.UserLimitForm;
@@ -56,7 +56,7 @@ public class GroupCreationController {
                                  @Valid UserLimitForm limit) {
 
         // Zusätzlicher check: studentin kann keine lecture erstellen
-        ValidationService.validateCreateForm(token, create);
+        ValidationHelper.validateCreateForm(token, create);
 
         User user = new User(token);
         Group group = groupService.createGroup(user,
@@ -68,9 +68,9 @@ public class GroupCreationController {
 
         // ROLE_studentin kann kein CSV importieren
         if (token.getAccount().getRoles().contains("orga")) {
-            groupService.addUsersToGroup(CsvService.readCsvFile(create.getFile()), group, user);
+            groupService.addUsersToGroup(CsvHelper.readCsvFile(create.getFile()), group, user);
         }
 
-        return "redirect:/gruppen2/details/" + IdService.uuidToString(group.getId());
+        return "redirect:/gruppen2/details/" + IdHelper.uuidToString(group.getId());
     }
 }

src/main/java/mops/gruppen2/web/GroupDetailsController.java

@@ -4,12 +4,12 @@ import lombok.extern.log4j.Log4j2;
 import mops.gruppen2.aspect.annotation.TraceMethodCalls;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.User;
-import mops.gruppen2.domain.service.CsvService;
+import mops.gruppen2.domain.helper.CsvHelper;
+import mops.gruppen2.domain.helper.IdHelper;
+import mops.gruppen2.domain.helper.ValidationHelper;
 import mops.gruppen2.domain.service.GroupService;
-import mops.gruppen2.domain.service.IdService;
 import mops.gruppen2.domain.service.InviteService;
 import mops.gruppen2.domain.service.ProjectionService;
-import mops.gruppen2.domain.service.ValidationService;
 import mops.gruppen2.web.form.MetaForm;
 import mops.gruppen2.web.form.UserLimitForm;
 import org.keycloak.adapters.springsecurity.token.KeycloakAuthenticationToken;
@@ -63,7 +63,7 @@ public class GroupDetailsController {
         model.addAttribute("parent", parent);
 
         // Detailseite für nicht-Mitglieder
-        if (!ValidationService.checkIfMember(group, user)) {
+        if (!ValidationHelper.checkIfMember(group, user)) {
             return "preview";
         }
 
@@ -79,7 +79,7 @@ public class GroupDetailsController {
         User user = new User(token);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
 
-        if (ValidationService.checkIfMember(group, user)) {
+        if (ValidationHelper.checkIfMember(group, user)) {
             return "redirect:/gruppen2/details/" + groupId;
         }
 
@@ -97,7 +97,7 @@ public class GroupDetailsController {
         User user = new User(token);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
 
-        ValidationService.throwIfNoMember(group, user);
+        ValidationHelper.throwIfNoMember(group, user);
 
         groupService.deleteUser(user, group);
 
@@ -119,7 +119,7 @@ public class GroupDetailsController {
         String serverURL = actualURL.substring(0, actualURL.indexOf("gruppen2/"));
         String link = serverURL + "gruppen2/join/" + inviteService.getLinkByGroup(group);
 
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         model.addAttribute("group", group);
         model.addAttribute("link", link);
@@ -165,9 +165,9 @@ public class GroupDetailsController {
                                      @RequestParam(value = "file", required = false) MultipartFile file) {
 
         User user = new User(token);
-        Group group = projectionService.projectSingleGroup(IdService.stringToUUID(groupId));
+        Group group = projectionService.projectSingleGroup(IdHelper.stringToUUID(groupId));
 
-        groupService.addUsersToGroup(CsvService.readCsvFile(file), group, user);
+        groupService.addUsersToGroup(CsvHelper.readCsvFile(file), group, user);
 
         return "redirect:/gruppen2/details/" + groupId + "/edit";
     }
@@ -182,12 +182,12 @@ public class GroupDetailsController {
         User user = new User(token);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
 
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         groupService.toggleMemberRole(new User(userId), group);
 
         // Falls sich der User selbst die Rechte genommen hat
-        if (!ValidationService.checkIfAdmin(group, user)) {
+        if (!ValidationHelper.checkIfAdmin(group, user)) {
             return "redirect:/gruppen2/details/" + groupId;
         }
 
@@ -204,7 +204,7 @@ public class GroupDetailsController {
         User user = new User(token);
         Group group = projectionService.projectSingleGroup(UUID.fromString(groupId));
 
-        ValidationService.throwIfNoAdmin(group, user);
+        ValidationHelper.throwIfNoAdmin(group, user);
 
         // Der eingeloggte User kann sich nicht selbst entfernen (er kann aber verlassen)
         if (!userId.equals(user.getId())) {

src/main/java/mops/gruppen2/web/SearchAndInviteController.java

@@ -5,10 +5,10 @@ import mops.gruppen2.aspect.annotation.TraceMethodCalls;
 import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.GroupType;
 import mops.gruppen2.domain.User;
+import mops.gruppen2.domain.helper.ValidationHelper;
 import mops.gruppen2.domain.service.InviteService;
 import mops.gruppen2.domain.service.ProjectionService;
 import mops.gruppen2.domain.service.SearchService;
-import mops.gruppen2.domain.service.ValidationService;
 import org.keycloak.adapters.springsecurity.token.KeycloakAuthenticationToken;
 import org.springframework.stereotype.Controller;
 import org.springframework.ui.Model;
@@ -79,7 +79,7 @@ public class SearchAndInviteController {
         }
 
         // Bereits Mitglied
-        if (ValidationService.checkIfMember(group, user)) {
+        if (ValidationHelper.checkIfMember(group, user)) {
             return "redirect:/gruppen2/details/" + group.getId();
         }
 

src/main/java/mops/gruppen2/web/form/CreateForm.java

@@ -2,7 +2,7 @@ package mops.gruppen2.web.form;
 
 import lombok.Data;
 import mops.gruppen2.domain.GroupType;
-import mops.gruppen2.domain.service.IdService;
+import mops.gruppen2.domain.helper.IdHelper;
 import org.springframework.web.multipart.MultipartFile;
 
 import javax.validation.constraints.NotBlank;
@@ -24,6 +24,6 @@ public class CreateForm {
     }
 
     public UUID getParent() {
-        return getType() == GroupType.LECTURE ? IdService.emptyUUID() : IdService.stringToUUID(parent);
+        return getType() == GroupType.LECTURE ? IdHelper.emptyUUID() : IdHelper.stringToUUID(parent);
     }
 }

src/test/java/mops/gruppen2/domain/service/ControllerServiceTest.java

@@ -2,6 +2,7 @@ package mops.gruppen2.domain.service;
 
 import mops.gruppen2.Gruppen2Application;
 import mops.gruppen2.domain.Account;
+import mops.gruppen2.domain.helper.ValidationHelper;
 import mops.gruppen2.persistance.EventRepository;
 import org.junit.jupiter.api.extension.ExtendWith;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -23,7 +24,7 @@ class ControllerServiceTest {
     @Autowired
     EventStoreService eventStoreService;
     @Autowired
-    ValidationService validationService;
+    ValidationHelper validationHelper;
     @Autowired
     EventRepository eventRepository;
     @Autowired

src/test/java/mops/gruppen2/domain/service/GroupServiceTest.java

@@ -6,6 +6,7 @@ import mops.gruppen2.domain.Group;
 import mops.gruppen2.domain.GroupType;
 import mops.gruppen2.domain.User;
 import mops.gruppen2.domain.event.Event;
+import mops.gruppen2.domain.helper.ValidationHelper;
 import mops.gruppen2.persistance.EventRepository;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
@@ -53,7 +54,7 @@ class GroupServiceTest {
     @Autowired
     private EventStoreService eventStoreService;
     @Autowired
-    private ValidationService validationService;
+    private ValidationHelper validationHelper;
     @Autowired
     private InviteService inviteService;