List all groups on OMERO (#78)

* Add a method to get the entire list of groups
* Fix typos
* Add test

src/main/java/fr/igred/omero/Client.java

@@ -42,6 +42,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.NoSuchElementException;
+import java.util.Objects;
 import java.util.concurrent.ExecutionException;
 import java.util.stream.Collectors;
 
@@ -365,13 +366,36 @@ public GroupWrapper getGroup(long groupId)
         ExperimenterGroup group = ExceptionHandler.of(getGateway(), g -> g.getAdminService(getCtx()).getGroup(groupId))
                                                   .rethrow(ApiUsageException.class,
                                                            (m, e) -> new NoSuchElementException(m),
-                                                           "User not found: " + groupId)
+                                                           "Group not found: " + groupId)
                                                   .handleServiceOrServer("Cannot retrieve group: " + groupId)
                                                   .get();
         return new GroupWrapper(new GroupData(group));
     }
 
 
+    /**
+     * Returns all the groups on OMERO.
+     *
+     * @return See above.
+     *
+     * @throws ServiceException       Cannot connect to OMERO.
+     * @throws AccessException        Cannot access data.
+     */
+    public List<GroupWrapper> getGroups()
+    throws ServiceException, AccessException {
+        String error = "Cannot retrieve the groups on OMERO";
+        return ExceptionHandler.of(getGateway(),
+                                   g -> g.getAdminService(getCtx()).lookupGroups())
+                               .handleOMEROException(error)
+                               .get()
+                               .stream()
+                               .filter(Objects::nonNull)
+                               .map(GroupData::new)
+                               .map(GroupWrapper::new)
+                               .collect(Collectors.toList());
+    }
+
+
     /**
      * Gets the client associated with the username in the parameters. The user calling this function needs to have
      * administrator rights. All action realized with the client returned will be considered as his.

src/main/java/fr/igred/omero/repository/ScreenWrapper.java

@@ -50,11 +50,11 @@ public class ScreenWrapper extends GenericRepositoryObjectWrapper<ScreenData> {
 
 
     /**
-     * Constructor of the ProjectWrapper class. Creates a new project and saves it to OMERO.
+     * Constructor of the ScreenWrapper class. Creates a new screen and saves it to OMERO.
      *
      * @param client      The client handling the connection.
-     * @param name        Project name.
-     * @param description Project description.
+     * @param name        Screen name.
+     * @param description Screen description.
      *
      * @throws ServiceException   Cannot connect to OMERO.
      * @throws AccessException    Cannot access data.

src/test/java/fr/igred/omero/ClientTest.java

@@ -19,6 +19,7 @@
 
 
 import fr.igred.omero.meta.ExperimenterWrapper;
+import fr.igred.omero.meta.GroupWrapper;
 import fr.igred.omero.repository.DatasetWrapper;
 import fr.igred.omero.repository.ImageWrapper;
 import fr.igred.omero.repository.PlateWrapper;
@@ -372,4 +373,11 @@ void testGetAllWellsForUser2() throws Exception {
         assertEquals(0, wells.size());
     }
 
+
+    @Test
+    void testGetAllGroups() throws Exception {
+        List<GroupWrapper> groups = client.getGroups();
+        assertEquals(7, groups.size());
+    }
+
 }