diff --git a/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java b/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
index 6c9634e..7b90d64 100644
--- a/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
+++ b/restservice/src/main/java/com/plannaplan/controllers/ExchangeController.java
@@ -3,6 +3,8 @@ package com.plannaplan.controllers;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.stream.Collector;
+import java.util.stream.Collectors;
 
 import com.plannaplan.App;
 import com.plannaplan.entities.Assignment;
@@ -36,12 +38,6 @@ import io.swagger.annotations.ApiOperation;
 @RequestMapping("/api/" + App.API_VERSION + "/exchanges")
 @Api(tags = { "Exchange" }, value = "Exchange", description = "Endpoint to exchange with accepted assignments.")
 public class ExchangeController extends TokenBasedController{
-  
-
-    /*
-        * Endpoint do wylistowania exchangow użytkownika
-        * Endpoint do usuwania exchanga 
-    */
 
     @Autowired
     private GroupService groupService;
@@ -61,6 +57,11 @@ public class ExchangeController extends TokenBasedController{
                                         .orElseThrow(() -> new UserNotFoundException("Invalid token"));
         final Long assignmentId = exchangeRequest.get("assignment");
         final Long groupId = exchangeRequest.get("group");
+        final List<Long> ownedGroups = asker.getStudentRegisteredGrups().stream().map(Groups::getId).collect(Collectors.toList()); 
+
+        if(ownedGroups.contains(groupId)){
+            return new ResponseEntity<>("User has already got this group.", HttpStatus.BAD_REQUEST);
+        }
 
         if(assignmentId == null || groupId == null ){
             return new ResponseEntity<>("Some of values are missing", HttpStatus.BAD_REQUEST);
diff --git a/restservice/src/test/java/com/plannaplan/controllers/ExchangeControllerTest.java b/restservice/src/test/java/com/plannaplan/controllers/ExchangeControllerTest.java
new file mode 100644
index 0000000..613dd8a
--- /dev/null
+++ b/restservice/src/test/java/com/plannaplan/controllers/ExchangeControllerTest.java
@@ -0,0 +1,65 @@
+package com.plannaplan.controllers;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ContextConfiguration;
+import org.springframework.test.context.junit4.SpringRunner;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.test.web.servlet.setup.MockMvcBuilders;
+
+import static org.junit.Assert.assertTrue;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+import javax.validation.constraints.AssertTrue;
+
+@RunWith(SpringRunner.class)
+@SpringBootTest
+@ContextConfiguration
+public class ExchangeControllerTest extends AbstractControllerTest{
+    
+    @Test
+    public void shouldGetAllUsersExchanges(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldFailGettingExchange(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldFailPostDueToExchangeNoFound(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldInsertExchange(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldDenyExchangeDueToAssigmentOverlapping(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldDenyPostDueToAssignmentNotAccepted(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldFailDeleteDueToWrongPermissions(){
+	assertTrue(false);
+    }
+
+    @Test
+    public void shouldFailDeleteDueToExchangeNoFound(){
+	assertTrue(false);
+    }
+    @Test
+    public void shouldFailPostDueToGroupAlreadyAccepted(){
+	assertTrue(false);
+    }
+}