diff --git a/back_end/pom.xml b/back_end/pom.xml
index a2c98b2..4707f2a 100644
--- a/back_end/pom.xml
+++ b/back_end/pom.xml
@@ -49,7 +49,7 @@
 		</dependency>
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
-			<artifactId>spring-boot-starter-webmvc</artifactId>
+			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
 		<dependency>
 			<groupId>org.thymeleaf.extras</groupId>
@@ -97,6 +97,11 @@
 			<artifactId>spring-boot-starter-thymeleaf-test</artifactId>
 			<scope>test</scope>
 		</dependency>
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-test</artifactId>
+			<scope>test</scope>
+		</dependency>
 		<dependency>
 			<groupId>org.projectlombok</groupId>
 			<artifactId>lombok</artifactId>
diff --git a/back_end/src/main/java/hackathon/FrisbYEE/rest/ActiviteResource.java b/back_end/src/main/java/hackathon/FrisbYEE/rest/ActiviteResource.java
index 83a7426..aefeed5 100644
--- a/back_end/src/main/java/hackathon/FrisbYEE/rest/ActiviteResource.java
+++ b/back_end/src/main/java/hackathon/FrisbYEE/rest/ActiviteResource.java
@@ -37,11 +37,7 @@ public class ActiviteResource {
 
         try {
             Session session = sessionDAO.findById(dto.getSessionId()).get();
-            Activite activite = new Activite();
-            activite.setName(dto.getName());
-            activite.setTheme(dto.getTheme());
-            activite.setDuree(dto.getDuree() != null ? dto.getDuree() : 0L);
-            activite.setDataActivite(dto.getDataActivite());
+            Activite activite = mapToEntity(dto);
             activite.setSession(session);
             activiteDAO.save(activite);
         } catch (Exception ex) {
@@ -90,14 +86,7 @@ public class ActiviteResource {
     public ResponseEntity<ActiviteDTO> getActivityById(@PathVariable("id") int id) {
         try {
             Activite activite = activiteDAO.findById(id).get();
-            ActiviteDTO dto = new ActiviteDTO();
-            dto.setName(activite.getName());
-            dto.setId(activite.getId());
-            dto.setTheme(activite.getTheme());
-            dto.setDuree(activite.getDuree());
-            dto.setDataActivite(activite.getDataActivite());
-            dto.setSessionId(activite.getSession() != null ? activite.getSession().getId() : null);
-
+            ActiviteDTO dto = mapToDTO(activite);
             return ResponseEntity.ok(dto);
         } catch (Exception ex) {
             return ResponseEntity.status(HttpStatus.NOT_FOUND).body(null);
@@ -110,16 +99,7 @@ public class ActiviteResource {
     public ResponseEntity<List<ActiviteDTO>> getAllActivity() {
         try {
             List<Activite> activites = activiteDAO.findAll();
-            List<ActiviteDTO> dtos = activites.stream().map(activite -> {
-                ActiviteDTO dto = new ActiviteDTO();
-                dto.setName(activite.getName());
-                dto.setId(activite.getId());
-                dto.setTheme(activite.getTheme());
-                dto.setDuree(activite.getDuree());
-                dto.setDataActivite(activite.getDataActivite());
-                dto.setSessionId(activite.getSession() != null ? activite.getSession().getId() : null);
-                return dto;
-            }).collect(Collectors.toList());
+            List<ActiviteDTO> dtos = activites.stream().map(this::mapToDTO).collect(Collectors.toList());
             return ResponseEntity.ok(dtos);
         } catch (Exception ex) {
             return ResponseEntity.status(HttpStatus.NOT_FOUND).body(null);
@@ -133,16 +113,7 @@ public class ActiviteResource {
     public ResponseEntity<List<ActiviteDTO>> getActivityByTheme(@PathVariable("theme") String theme) {
         try {
             List<Activite> activites = activiteDAO.findByTheme(theme);
-            List<ActiviteDTO> dtos = activites.stream().map(activite -> {
-                ActiviteDTO dto = new ActiviteDTO();
-                dto.setName(activite.getName());
-                dto.setId(activite.getId());
-                dto.setTheme(activite.getTheme());
-                dto.setDuree(activite.getDuree());
-                dto.setDataActivite(activite.getDataActivite());
-                dto.setSessionId(activite.getSession() != null ? activite.getSession().getId() : null);
-                return dto;
-            }).collect(Collectors.toList());
+            List<ActiviteDTO> dtos = activites.stream().map(this::mapToDTO).collect(Collectors.toList());
             return ResponseEntity.ok(dtos);
         } catch (Exception ex) {
             return ResponseEntity.status(HttpStatus.NOT_FOUND).body(null);
@@ -150,4 +121,24 @@ public class ActiviteResource {
 
     }
 
+    private Activite mapToEntity(ActiviteDTO dto) {
+        Activite activite = new Activite();
+        //ID géré par Postgre ?
+        activite.setName(dto.getName());
+        activite.setTheme(dto.getTheme());
+        activite.setDuree(dto.getDuree());
+        activite.setDataActivite(dto.getDataActivite());
+        return activite;
+    }
+
+    private ActiviteDTO mapToDTO(Activite activite) {
+        ActiviteDTO dto = new ActiviteDTO();
+        dto.setName(activite.getName());
+        dto.setTheme(activite.getTheme());
+        dto.setDuree(activite.getDuree());
+        dto.setDataActivite(activite.getDataActivite());
+        dto.setSessionId(activite.getSession() != null ? activite.getSession().getId() : null);
+        return dto;
+    }
+
 }
diff --git a/back_end/src/main/java/hackathon/FrisbYEE/rest/AthleteResource.java b/back_end/src/main/java/hackathon/FrisbYEE/rest/AthleteResource.java
index 6944a35..a0230f0 100644
--- a/back_end/src/main/java/hackathon/FrisbYEE/rest/AthleteResource.java
+++ b/back_end/src/main/java/hackathon/FrisbYEE/rest/AthleteResource.java
@@ -37,10 +37,8 @@ public class AthleteResource {
     @PostMapping("/create")
     @PreAuthorize("hasRole('Admin')") // Only admin can create??
     public ResponseEntity<AthleteDTO> create(@RequestBody AthleteDTO dto) {
-        Athlete athlete = new Athlete();
-        athlete.setName(dto.getName());
-        athlete.setCategorie(dto.getCategorie());
-        athlete.setNiveau(dto.getNiveau());
+        Athlete athlete = mapToEntity(dto);
+        athleteDAO.save(athlete);
         return ResponseEntity.status(HttpStatus.CREATED).body(mapToDTO(athlete));
     }
 
@@ -108,6 +106,16 @@ public class AthleteResource {
         dto.setNiveau(athlete.getNiveau());
         return dto;
     }
+
+    private Athlete mapToEntity(AthleteDTO dto) {
+        Athlete athlete = new Athlete();
+        athlete.setId(dto.getId());
+        athlete.setName(dto.getName());
+        athlete.setCategorie(dto.getCategorie());
+        athlete.setNiveau(dto.getNiveau());
+        return athlete;
+    }
+
     @GetMapping("/athlete/{id}/session")
     public List<SessionDTO> getSessionsAthlete(@PathVariable Integer athleteId)  {
         // return pet
diff --git a/back_end/src/main/java/hackathon/FrisbYEE/rest/CoachResource.java b/back_end/src/main/java/hackathon/FrisbYEE/rest/CoachResource.java
index ddb8c85..c6027a9 100644
--- a/back_end/src/main/java/hackathon/FrisbYEE/rest/CoachResource.java
+++ b/back_end/src/main/java/hackathon/FrisbYEE/rest/CoachResource.java
@@ -20,8 +20,7 @@ public class CoachResource {
     @PostMapping("/create")
     @PreAuthorize("hasRole('Admin')") // Only admin can create
     public ResponseEntity<CoachDTO> create(@RequestBody CoachDTO dto) {
-        Coach coach = new Coach();
-        coach.setName(dto.getName());
+        Coach coach = mapToEntity(dto);
         coachDAO.save(coach);
         return ResponseEntity.status(HttpStatus.CREATED).body(mapToDTO(coach));
     }
@@ -52,7 +51,8 @@ public class CoachResource {
                 .orElseThrow(() -> new ResponseStatusException(HttpStatus.NOT_FOUND, "Coach not found"));
         if (dto.getName() != null) coach.setName(dto.getName());
         coachDAO.save(coach);
-        return ResponseEntity.ok(mapToDTO(coach));
+        CoachDTO updatedDto = mapToDTO(coach);
+        return ResponseEntity.ok(updatedDto);
     }
 
     @DeleteMapping("/delete/{id}")
@@ -70,5 +70,12 @@ public class CoachResource {
         dto.setName(coach.getName());
         return dto;
     }
+
+    private Coach mapToEntity(CoachDTO dto) {
+        Coach coach = new Coach();
+        coach.setId(dto.getId());
+        coach.setName(dto.getName());
+        return coach;
+    }
 }
 
diff --git a/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java b/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java
index dfdf6db..ec03899 100644
--- a/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java
+++ b/back_end/src/main/java/hackathon/FrisbYEE/rest/SessionResource.java
@@ -40,16 +40,7 @@ public class SessionResource {
     @PreAuthorize("hasRole('Coach')")
     public ResponseEntity<?> create(@RequestBody SessionDTO dto) {
         try {
-            List<Athlete> athletes = athleteDAO.findAllById(dto.getAthleteIds());
-            Coach coach = coachDAO.findById(dto.getCoachId()).get();
-            Session session = new Session();
-            session.setName(dto.getName());
-            session.setIsRecurrent(dto.getIsRecurrent());
-            session.setCreneau(dto.getCreneau());
-            session.setDuree(dto.getDuree());
-            session.setGroupe(dto.getGroupe());
-            session.setCoach(coach);
-            session.setAthletes(athletes);
+            Session session = maptoEntity(dto);
             sessionDAO.save(session);
             return ResponseEntity.status(HttpStatus.CREATED).body(maptoDTO(session));
         } catch (Exception ex) {
@@ -143,4 +134,31 @@ public class SessionResource {
         }
         return dto;
     }
+
+    private Session maptoEntity(SessionDTO dto) {
+        Session session = new Session();
+        session.setId(dto.getId());
+        session.setName(dto.getName());
+        session.setIsRecurrent(dto.getIsRecurrent());
+        session.setCreneau(dto.getCreneau());
+        session.setDuree(dto.getDuree());
+        session.setGroupe(dto.getGroupe());
+        // Coach
+        if (dto.getCoachId() != null) {
+            Coach coach = new Coach();
+            coach.setId(dto.getCoachId());
+            session.setCoach(coach);
+        }
+        // Athletes
+        if (dto.getAthleteIds() != null) {
+            List<Athlete> athletes = athleteDAO.findAllById(dto.getAthleteIds());
+            session.setAthletes(athletes);
+        }
+        // Activites
+        if (dto.getActiviteIds() != null) {
+            List<Activite> activites = activiteDAO.findAllById(dto.getActiviteIds());
+            session.setActivites(activites);
+        }
+        return session;
+    }
 }
diff --git a/back_end/src/test/java/hackathon/FrisbYEE/FrisbYeeApplicationTests.java b/back_end/src/test/java/hackathon/FrisbYEE/FrisbYeeApplicationTests.java
index a6f781d..5a4683f 100644
--- a/back_end/src/test/java/hackathon/FrisbYEE/FrisbYeeApplicationTests.java
+++ b/back_end/src/test/java/hackathon/FrisbYEE/FrisbYeeApplicationTests.java
@@ -1,13 +1,27 @@
 package hackathon.FrisbYEE;
 
+import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
-import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.web.servlet.client.RestTestClient;
 
-@SpringBootTest
-class FrisbYeeApplicationTests {
+import hackathon.FrisbYEE.rest.AthleteResource;
 
-	@Test
-	void contextLoads() {
+
+class FrisbYEEApplicationTests {
+
+	//Controller
+	private AthleteResource athleteResource;
+	private RestTestClient mockMvc;
+
+	@BeforeEach
+	void setUp() {
+		athleteResource = new AthleteResource();
+		mockMvc = RestTestClient.bindToController(athleteResource).build();
 	}
 
+    @Test
+    void shouldReturnUsers() throws Exception {
+        //mockMvc.perform(get("/api/users"))
+          //     .andExpect(status().isOk());
+    }
 }