diff --git a/.idea/misc.xml b/.idea/misc.xml
index f66521e..a2598f9 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -3,7 +3,7 @@
   <component name="JavaScriptSettings">
     <option name="languageLevel" value="ES6" />
   </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="12" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java b/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java
index 0388d13..28a0bd3 100644
--- a/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java
+++ b/src/main/java/com/example/cosmos_serversb/resources/GroupsRest.java
@@ -13,7 +13,7 @@
     @GET
     public String getGroupsListByUid(@QueryParam("uId") String uId, @QueryParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.getGroupsListByUid(uId));
         return json;
     }
 
@@ -21,7 +21,7 @@
     @POST
     public String createGroup(@FormParam("name") String name, @FormParam("uId") String uId, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.createGroup(name, uId));
         return json;
     }
 
@@ -29,7 +29,7 @@
     @GET
     public String getGroupByGid(@PathParam("gId") String gId, @QueryParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.getGroupByGid(gId));
         return json;
     }
 
@@ -37,7 +37,7 @@
     @DELETE
     public String deleteGroup(@PathParam("gId") String gId, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.deleteGroup(gId));
         return json;
     }
 
@@ -45,7 +45,7 @@
     @GET
     public String getGroupMembersListByGid(@PathParam("gId") String gId, @QueryParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.getMembersListByGid(gId));
         return json;
     }
 
@@ -53,7 +53,7 @@
     @POST
     public String addMember(@PathParam("gId") String gId, @FormParam("uId") String uId, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.addMember(gId, uId));
         return json;
     }
 
@@ -61,7 +61,7 @@
     @DELETE
     public String deleteMember(@PathParam("gId") String gId, @FormParam("uId") String uId, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.deleteMember(gId, uId));
         return json;
     }
 
@@ -69,7 +69,7 @@
     @GET
     public String getRequestsListByGid(@PathParam("gId") String gId, @QueryParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.getRequestsListByGid(gId));
         return json;
     }
 
@@ -77,7 +77,7 @@
     @POST
     public String addRequests(@PathParam("gId") String gId, @FormParam("uId") String uId, @FormParam("product") String product, @FormParam("deadline") String deadline, @FormParam("location") int location, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.addRequests(gId, uId, product, deadline, location));
         return json;
     }
 
@@ -85,7 +85,7 @@
     @GET
     public String getRequestsDetailByGidAndRid(@PathParam("gId") String gId, @PathParam("rId") String rId, @QueryParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.getRequestsDetailByGidAndRid(gId, rId));
         return json;
     }
 
@@ -93,7 +93,7 @@
     @PUT
     public String updateRequest(@PathParam("gId") String gId, @PathParam("rId") String rId, @FormParam("uId") String uId, @FormParam("product") String product, @FormParam("deadline") String deadline, @FormParam("location") int location, @FormParam("done") boolean done, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.updateRequest(gId, rId, uId, product, deadline, location, done));
         return json;
     }
 
@@ -101,7 +101,7 @@
     @DELETE
     public String deleteRequest(@PathParam("gId") String gId, @PathParam("rId") String rId, @FormParam("token") String token) throws JsonProcessingException{
         ObjectMapper mapper = new ObjectMapper();
-        String json = mapper.writeValueAsString(null);
+        String json = mapper.writeValueAsString(Groups.deleteRequest(gId, rId));
         return json;
     }
 }