Change interfaces to use Set instead of List

20 files changed, 59 insertions, 56 deletions

diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/controller/RegistrationWindowController.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/controller/RegistrationWindowController.java
index bf413bb..9ed6147 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/controller/RegistrationWindowController.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/controller/RegistrationWindowController.java
@@ -15,8 +15,10 @@ import java.time.LocalDateTime;
 import java.time.LocalTime;
 import java.time.OffsetDateTime;
 import java.util.EnumSet;
+import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 import javafx.beans.property.SimpleStringProperty;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
@@ -78,7 +80,7 @@ public class RegistrationWindowController {
     public void initialize() {
         // will have to be replaced for FlowPane
         try {
-            List<Vehicle> vehicles = vehicleService.list(EnumSet.of(Status.ABGEMELDET));
+            Set<Vehicle> vehicles = vehicleService.list(EnumSet.of(Status.ABGEMELDET));
             tcVehicles.setCellValueFactory(x -> new SimpleStringProperty(x.getValue().name()));
             tvVehicles.setItems(FXCollections.observableArrayList(vehicles));
         } catch (ServiceException e) {
@@ -92,7 +94,7 @@ public class RegistrationWindowController {
             alert.show();
         }
         try {
-            List<Employee> employees = employeeService.list();
+            Set<Employee> employees = employeeService.list();
             tcEmployees.setCellValueFactory(x -> new SimpleStringProperty(x.getValue().name()));
             tvEmployees.setItems(FXCollections.observableArrayList(employees));
         } catch (ServiceException e) {
@@ -147,7 +149,7 @@ public class RegistrationWindowController {
     public void create() {
         LOG.debug("Create Button clicked");
 
-        List<Registration> registrations = new LinkedList<>();
+        Set<Registration> registrations = new HashSet<>();
 
         for (Employee employee : chosenEmployees) {
             registrations.add(
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/DBOperationDAO.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/DBOperationDAO.java
index 672424a..1423240 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/DBOperationDAO.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/DBOperationDAO.java
@@ -10,7 +10,7 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Timestamp;
 import java.util.EnumSet;
-import java.util.List;
+import java.util.Set;
 
 public class DBOperationDAO implements OperationDAO {
 
@@ -118,7 +118,7 @@ public class DBOperationDAO implements OperationDAO {
     }
 
     @Override
-    public List<Operation> list(EnumSet<Status> statuses) throws PersistenceException {
+    public Set<Operation> list(EnumSet<Status> statuses) throws PersistenceException {
         return null;
     }
 
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDAO.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDAO.java
index 564ce7c..539a8e5 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDAO.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDAO.java
@@ -3,7 +3,7 @@ package at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dao;
 import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Employee;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ElementNotFoundException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
-import java.util.List;
+import java.util.Set;
 
 public interface EmployeeDAO {
 
@@ -31,7 +31,7 @@ public interface EmployeeDAO {
      * @return list containing all stored employees
      * @throws PersistenceException if loading the stored employees failed
      */
-    List<Employee> list() throws PersistenceException;
+    Set<Employee> list() throws PersistenceException;
 
     /**
      * Remove employee with the given id from the store.
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDatabaseDao.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDatabaseDao.java
index 3e4ba12..8da79e7 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDatabaseDao.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/EmployeeDatabaseDao.java
@@ -11,8 +11,8 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.sql.Timestamp;
-import java.util.ArrayList;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.stereotype.Repository;
@@ -89,12 +89,12 @@ public class EmployeeDatabaseDao implements EmployeeDAO {
     }
 
     @Override
-    public List<Employee> list() throws PersistenceException {
+    public Set<Employee> list() throws PersistenceException {
 
         try {
             ResultSet rs = listEmployee.executeQuery();
 
-            List<Employee> employees = new ArrayList<>();
+            Set<Employee> employees = new HashSet<>();
             while (rs.next()) {
 
                 Employee employee =
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/OperationDAO.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/OperationDAO.java
index dd1a189..da90cc8 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/OperationDAO.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/OperationDAO.java
@@ -5,7 +5,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Operation.S
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ElementNotFoundException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
 import java.util.EnumSet;
-import java.util.List;
+import java.util.Set;
 
 public interface OperationDAO {
 
@@ -44,7 +44,7 @@ public interface OperationDAO {
      * @return list containing all matched operations
      * @throws PersistenceException if loading the stored operations failed
      */
-    List<Operation> list(EnumSet<Status> statuses) throws PersistenceException;
+    Set<Operation> list(EnumSet<Status> statuses) throws PersistenceException;
 
     int connectVehicleToOperation(long vehicleID, long operationID) throws PersistenceException;
 }
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDAO.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDAO.java
index ba8f909..36b6f1b 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDAO.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDAO.java
@@ -3,7 +3,7 @@ package at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dao;
 import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Registration;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ElementNotFoundException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
-import java.util.List;
+import java.util.Set;
 
 public interface RegistrationDAO {
 
@@ -15,7 +15,7 @@ public interface RegistrationDAO {
      * @return a list of the ids that were assigned
      * @throws PersistenceException if the registration could not be persisted
      */
-    List<Long> add(long vehicleId, List<Registration> registrations) throws PersistenceException;
+    Set<Long> add(long vehicleId, Set<Registration> registrations) throws PersistenceException;
 
     /**
      * Make registration with the given id inactive.
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDatabaseDAO.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDatabaseDAO.java
index 8fbcd18..13aeffc 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDatabaseDAO.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/RegistrationDatabaseDAO.java
@@ -10,8 +10,8 @@ import java.sql.ResultSet;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.sql.Timestamp;
-import java.util.LinkedList;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -47,9 +47,9 @@ public class RegistrationDatabaseDAO implements RegistrationDAO {
     }
 
     @Override
-    public List<Long> add(long vehicleId, List<Registration> registrations)
+    public Set<Long> add(long vehicleId, Set<Registration> registrations)
             throws PersistenceException {
-        List<Long> returnValues = new LinkedList<>();
+        Set<Long> returnValues = new HashSet<>();
         try {
             connection.setAutoCommit(false);
             for (Registration registration : registrations) {
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDAO.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDAO.java
index 2f0df44..5782fd9 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDAO.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDAO.java
@@ -3,7 +3,7 @@ package at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dao;
 import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Vehicle;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ElementNotFoundException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
-import java.util.List;
+import java.util.Set;
 
 public interface VehicleDAO {
 
@@ -31,7 +31,7 @@ public interface VehicleDAO {
      * @return list containing all stored vehicles
      * @throws PersistenceException if loading the stored vehicles failed
      */
-    List<Vehicle> list() throws PersistenceException;
+    Set<Vehicle> list() throws PersistenceException;
 
     /**
      * Returns the vehicle with the given id.
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDatabaseDao.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDatabaseDao.java
index 3e8c0fc..dfdc04c 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDatabaseDao.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dao/VehicleDatabaseDao.java
@@ -11,8 +11,8 @@ import java.sql.Connection;
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
-import java.util.LinkedList;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 import org.springframework.stereotype.Repository;
 
 @Repository
@@ -103,9 +103,9 @@ public class VehicleDatabaseDao implements VehicleDAO {
     public void update(Vehicle vehicle) throws ElementNotFoundException, PersistenceException {}
 
     @Override
-    public List<Vehicle> list() throws PersistenceException {
+    public Set<Vehicle> list() throws PersistenceException {
         PreparedStatement pstmt = null;
-        List<Vehicle> result = new LinkedList<>();
+        Set<Vehicle> result = new HashSet<>();
         try {
             pstmt =
                     jdbcConnectionManager
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/Operation.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/Operation.java
index 6641437..d33995f 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/Operation.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/Operation.java
@@ -2,7 +2,7 @@ package at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto;
 
 import com.google.auto.value.AutoValue;
 import java.time.Instant;
-import java.util.List;
+import java.util.Set;
 import javax.annotation.Nullable;
 
 @AutoValue
@@ -30,7 +30,7 @@ public abstract class Operation {
 
     public abstract Status status();
 
-    public abstract List<Vehicle> vehicles();
+    public abstract Set<Vehicle> vehicles();
 
     @Nullable
     public abstract Instant created();
@@ -53,7 +53,7 @@ public abstract class Operation {
 
         public abstract Builder status(Status status);
 
-        public abstract Builder vehicles(List<Vehicle> vehicles);
+        public abstract Builder vehicles(Set<Vehicle> vehicles);
 
         public abstract Builder created(Instant created);
 
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/RegistrationValidator.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/RegistrationValidator.java
index 295b615..610426c 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/RegistrationValidator.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/dto/RegistrationValidator.java
@@ -7,6 +7,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException
 import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -16,7 +17,7 @@ public class RegistrationValidator {
 
     private RegistrationValidator() {}
 
-    public static void validate(Vehicle vehicle, List<Registration> registrations)
+    public static void validate(Vehicle vehicle, Set<Registration> registrations)
             throws InvalidVehicleException, InvalidRegistrationException {
         /*
         Vehicles and Employees are assumed to be valid.
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeService.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeService.java
index 8753504..f7f8e71 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeService.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeService.java
@@ -3,7 +3,7 @@ package at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.service;
 import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Employee;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidEmployeeException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
-import java.util.List;
+import java.util.Set;
 
 public interface EmployeeService {
 
@@ -33,7 +33,7 @@ public interface EmployeeService {
      * @return list containing all stored employees
      * @throws ServiceException if loading the stored employees failed
      */
-    List<Employee> list() throws ServiceException;
+    Set<Employee> list() throws ServiceException;
 
     /**
      * Remove employee with the given id from the store.
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeServiceImpl.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeServiceImpl.java
index ed0fb1c..b4119b0 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeServiceImpl.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/EmployeeServiceImpl.java
@@ -6,7 +6,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.EmployeeVal
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidEmployeeException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
-import java.util.List;
+import java.util.Set;
 import org.springframework.stereotype.Service;
 
 @Service
@@ -35,7 +35,7 @@ public class EmployeeServiceImpl implements EmployeeService {
     }
 
     @Override
-    public List<Employee> list() throws ServiceException {
+    public Set<Employee> list() throws ServiceException {
 
         try {
             return employeePersistence.list();
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationService.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationService.java
index e21c10b..98a2068 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationService.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationService.java
@@ -7,8 +7,8 @@ import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidOperationExcepti
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
 import java.util.EnumSet;
-import java.util.List;
-import javafx.collections.transformation.SortedList;
+import java.util.Set;
+import java.util.SortedSet;
 
 public interface OperationService {
 
@@ -32,7 +32,7 @@ public interface OperationService {
      * @throws ServiceException if the vehicles could not be loaded or the operation could not be
      *     persisted
      */
-    void requestVehicles(long operationId, List<Long> vehicleIds)
+    void requestVehicles(long operationId, Set<Long> vehicleIds)
             throws InvalidOperationException, InvalidVehicleException, ServiceException;
 
     /**
@@ -56,7 +56,7 @@ public interface OperationService {
      * @throws InvalidOperationException if the operationId is invalid or does not exist
      * @throws ServiceException if loading the stored vehicles failed
      */
-    SortedList<Vehicle> rankVehicles(long operationId)
+    SortedSet<Vehicle> rankVehicles(long operationId)
             throws InvalidOperationException, ServiceException;
 
     /**
@@ -66,5 +66,5 @@ public interface OperationService {
      * @return list containing all matched operations
      * @throws ServiceException if loading the stored operations failed
      */
-    List<Operation> list(EnumSet<Status> statuses) throws ServiceException;
+    Set<Operation> list(EnumSet<Status> statuses) throws ServiceException;
 }
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationServiceImpl.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationServiceImpl.java
index 05a548c..7b69886 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationServiceImpl.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/OperationServiceImpl.java
@@ -10,8 +10,8 @@ import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
 import java.util.EnumSet;
-import java.util.List;
-import javafx.collections.transformation.SortedList;
+import java.util.Set;
+import java.util.SortedSet;
 
 public class OperationServiceImpl implements OperationService {
 
@@ -24,7 +24,7 @@ public class OperationServiceImpl implements OperationService {
 
     @Override
     public long add(Operation operation) throws InvalidOperationException, ServiceException {
-        List<Vehicle> vehicles = operation.vehicles();
+        Set<Vehicle> vehicles = operation.vehicles();
         boolean rtw = false;
         if (faultyInput(operation.opCode())) {
             throw new InvalidOperationException("Code ist ungültig!");
@@ -111,7 +111,7 @@ public class OperationServiceImpl implements OperationService {
     }
 
     @Override
-    public void requestVehicles(long operationId, List<Long> vehicleIds)
+    public void requestVehicles(long operationId, Set<Long> vehicleIds)
             throws InvalidOperationException, InvalidVehicleException, ServiceException {}
 
     @Override
@@ -119,13 +119,13 @@ public class OperationServiceImpl implements OperationService {
             throws InvalidOperationException, ServiceException {}
 
     @Override
-    public SortedList<Vehicle> rankVehicles(long operationId)
+    public SortedSet<Vehicle> rankVehicles(long operationId)
             throws InvalidOperationException, ServiceException {
         return null;
     }
 
     @Override
-    public List<Operation> list(EnumSet<Status> statuses) throws ServiceException {
+    public Set<Operation> list(EnumSet<Status> statuses) throws ServiceException {
         return null;
     }
 }
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationService.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationService.java
index c345a2b..b7d8eef 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationService.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationService.java
@@ -4,7 +4,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Registratio
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidRegistrationException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
-import java.util.List;
+import java.util.Set;
 
 public interface RegistrationService {
 
@@ -18,7 +18,7 @@ public interface RegistrationService {
      * @throws InvalidRegistrationException if the registration is invalid
      * @throws ServiceException if the registration could not be persisted
      */
-    List<Long> add(long vehicleId, List<Registration> registrations)
+    Set<Long> add(long vehicleId, Set<Registration> registrations)
             throws InvalidVehicleException, InvalidRegistrationException, ServiceException;
 
     /**
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationServiceImpl.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationServiceImpl.java
index 8203ef3..54d46e7 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationServiceImpl.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/RegistrationServiceImpl.java
@@ -10,7 +10,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidRegistrationExce
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
-import java.util.List;
+import java.util.Set;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.springframework.beans.factory.annotation.Autowired;
@@ -31,7 +31,7 @@ public class RegistrationServiceImpl implements RegistrationService {
     }
 
     @Override
-    public List<Long> add(long vehicleId, List<Registration> registrations)
+    public Set<Long> add(long vehicleId, Set<Registration> registrations)
             throws InvalidVehicleException, InvalidRegistrationException, ServiceException {
 
         if (vehicleId <= 0) throw new InvalidVehicleException("VehicleId invalid");
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleService.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleService.java
index 6a96bc5..fe09ca1 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleService.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleService.java
@@ -5,7 +5,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.einsatzverwaltung.dto.Vehicle.Sta
 import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
 import java.util.EnumSet;
-import java.util.List;
+import java.util.Set;
 
 public interface VehicleService {
 
@@ -36,7 +36,7 @@ public interface VehicleService {
      * @return list containing all stored vehicles
      * @throws ServiceException if loading the stored vehicles failed
      */
-    List<Vehicle> list(EnumSet<Status> statuses) throws ServiceException;
+    Set<Vehicle> list(EnumSet<Status> statuses) throws ServiceException;
 
     /**
      * Remove vehicle with the given id from the store.
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleServiceImpl.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleServiceImpl.java
index bbe668b..92386e1 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleServiceImpl.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/service/VehicleServiceImpl.java
@@ -8,7 +8,7 @@ import at.ac.tuwien.sepm.assignment.groupphase.exception.InvalidVehicleException
 import at.ac.tuwien.sepm.assignment.groupphase.exception.PersistenceException;
 import at.ac.tuwien.sepm.assignment.groupphase.exception.ServiceException;
 import java.util.EnumSet;
-import java.util.List;
+import java.util.Set;
 import java.util.stream.Collectors;
 import org.springframework.stereotype.Service;
 
@@ -73,13 +73,13 @@ public class VehicleServiceImpl implements VehicleService {
     }
 
     @Override
-    public List<Vehicle> list(EnumSet<Status> statuses) throws ServiceException {
+    public Set<Vehicle> list(EnumSet<Status> statuses) throws ServiceException {
 
         if (statuses == null) {
             throw new ServiceException("statuses may not be null");
         }
 
-        List<Vehicle> vehicles;
+        Set<Vehicle> vehicles;
 
         try {
             vehicles = vehiclePersistence.list();
@@ -89,7 +89,7 @@ public class VehicleServiceImpl implements VehicleService {
 
         return vehicles.stream()
                 .filter(vehicle -> statuses.contains(vehicle.status()))
-                .collect(Collectors.toList());
+                .collect(Collectors.toSet());
     }
 
     @Override
diff --git a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/userInterface/CreateOperationController.java b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/userInterface/CreateOperationController.java
index 5b645f3..7b04efe 100644
--- a/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/userInterface/CreateOperationController.java
+++ b/src/main/java/at/ac/tuwien/sepm/assignment/groupphase/einsatzverwaltung/userInterface/CreateOperationController.java
@@ -17,7 +17,7 @@ import java.lang.invoke.MethodHandles;
 import java.time.Instant;
 import java.util.EnumSet;
 import java.util.LinkedList;
-import java.util.List;
+import java.util.Set;
 import javafx.collections.FXCollections;
 import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
@@ -170,7 +170,7 @@ public class CreateOperationController {
                         .created(Instant.now())
                         .opCode(txtCode.getText())
                         .status(Status.ACTIVE)
-                        .vehicles(List.of(vehicles))
+                        .vehicles(Set.of(vehicles))
                         .severity(Severity.A)
                         .build();
         try {