feat: add getGroups(Boolean withTree) API (#78)

* Add a check on whether the exp time has expired in AuthService

* Update AuthService.java

* Add a method to get the tree structure of the group

* Update GroupService.java

---------

Co-authored-by: Eric Luo <[email protected]>

src/main/java/org/casbin/casdoor/service/GroupService.java

@@ -45,6 +45,17 @@ public List<Group> getGroups() throws IOException {
         return response.getData();
     }
 
+    public List<Group> getGroups(Boolean withTree) throws IOException {
+        if (!withTree) {
+            return getGroups();
+        }
+
+        CasdoorResponse<List<Group>, Object> response = doGet("get-groups",
+                Map.of("owner", config.organizationName, "withTree", "true"), new TypeReference<CasdoorResponse<List<Group>, Object>>() {
+                });
+        return response.getData();
+    }
+
     public CasdoorResponse<String, Object> addGroup(Group group) throws IOException {
         return modifyGroup(GroupOperations.ADD_GROUP, group, null);
     }
@@ -65,4 +76,4 @@ private <T1, T2> CasdoorResponse<T1, T2> modifyGroup(GroupOperations method, Gro
                 new TypeReference<CasdoorResponse<T1, T2>>() {
                 });
     }
-}
+}