feat: Add error handling for dataset endpoints & return dataset that is beeing returend for the abilty to get the id

src/main/java/de/uni_passau/fim/PADAS/group3/DataDash/controler/DatasetController.java

@@ -9,8 +9,11 @@ import de.uni_passau.fim.PADAS.group3.DataDash.model.Category;
 import de.uni_passau.fim.PADAS.group3.DataDash.model.Dataset;
 import de.uni_passau.fim.PADAS.group3.DataDash.model.DatasetService;
 import de.uni_passau.fim.PADAS.group3.DataDash.model.Type;
+
 import org.springframework.data.domain.Pageable;
 import org.springframework.data.web.config.EnableSpringDataWebSupport;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.data.domain.Sort;
 
 import java.util.UUID;
@@ -24,54 +27,60 @@ public class DatasetController {
     @Autowired
     private DatasetService datasetService;
     
-    // @GetMapping
-    // public List<Dataset> getAllDatasets() {
-    // return datasetService.getAllDatasets();
-    // }
-
     @GetMapping("/id/{id}")
-    public Dataset getDatasetById(@PathVariable("id") UUID id) {
+    public ResponseEntity<?> getDatasetById(@PathVariable("id") UUID id) {
-        return datasetService.getDatasetById(id);
+        Dataset d = datasetService.getDatasetById(id);
+        if (d == null) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+        return new ResponseEntity<>(d , HttpStatus.OK);
     }
 
+    @ResponseStatus(HttpStatus.CREATED)
     @PostMapping
     public Dataset createDataset(@RequestBody Dataset dataset) {
-        datasetService.addDataset(dataset);
+        return datasetService.addDataset(dataset);
-        // TODO: figure out what the fuck i need to do here
-        return null;
     }
 
-    // @PutMapping("/{id}")
-    // public Dataset updateDataset(@PathVariable("id") Long id, @RequestBody
-    // Dataset dataset) {
-    // return datasetService.updateDataset(id, dataset);
-    // }
-    //
-
     @DeleteMapping("/id/{id}")
-    public void deleteDataset(@PathVariable("id") UUID id) {
+    public ResponseEntity<?> deleteDataset(@PathVariable("id") UUID id) {
+        if (datasetService.getDatasetById(id) == null) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
         datasetService.deleteDataset(id);
+        return new ResponseEntity<>(HttpStatus.OK);
     }
 
     @PutMapping("/id/{id}/upvote")
-    public Dataset upvote(@PathVariable("id") UUID id) {
+    public ResponseEntity<?> upvote(@PathVariable("id") UUID id) {
+        if (datasetService.getDatasetById(id) == null) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
         datasetService.upvoteDataset(id);
-        return datasetService.getDatasetById(id);
+        return new ResponseEntity<>(datasetService.getDatasetById(id), HttpStatus.OK);
     }
 
     @PutMapping("/id/{id}/downvote")
-    public Dataset downvote(@PathVariable("id") UUID id) {
+    public ResponseEntity<?> downvote(@PathVariable("id") UUID id) {
+        if (datasetService.getDatasetById(id) == null) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
         datasetService.downvoteDataset(id);
-        return getDatasetById(id); // new ResponseEntity<>(null, HttpStatus.OK);
+        return new ResponseEntity<>(getDatasetById(id), HttpStatus.OK);
     }
 
     @PutMapping("/id/{id}/vote")
-    public Dataset postMethodName(@PathVariable("id") UUID id,
+    public ResponseEntity<?> postMethodName(@PathVariable("id") UUID id,
             @RequestParam("stars") int stars) {
-        if (stars > 0 && stars < 6) {
+        if (datasetService.getDatasetById(id) == null) {
-            datasetService.voteDataset(id, stars);
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
         }
-        return datasetService.getDatasetById(id);
+        if (!(stars > 0 && stars < 6)) {
+            return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
+        }
+        datasetService.voteDataset(id, stars);
+        return new ResponseEntity<>(datasetService.getDatasetById(id), HttpStatus.OK);
     }
 
     @GetMapping
@@ -88,7 +97,8 @@ public class DatasetController {
             @RequestParam(value = "category", required = false) Category category) {
         Pageable pageable = PageRequest.of(page, size,
                 Sort.by(direction.equals("asc") ? Sort.Direction.ASC : Sort.Direction.DESC, sort));
-        return datasetService.getDatasetsByOptionalCriteria(title, description, author, abst, type, rating, category,pageable);
+        return datasetService.getDatasetsByOptionalCriteria(title, description, author, abst, type, rating, category,
+                pageable);
     }
 
     @GetMapping("/search")

src/main/java/de/uni_passau/fim/PADAS/group3/DataDash/model/DatasetService.java

@@ -28,9 +28,9 @@ public class DatasetService {
         return datasetRepository.getDatasetById(id);
     }
 
-    public void addDataset(Dataset dataset) {
+    public Dataset addDataset(Dataset dataset) {
         dataset.setDate(LocalDate.now());
-        datasetRepository.save(dataset);
+        return datasetRepository.save(dataset);
     }
 
     public void updateDatasetTitle(UUID id, String title) {