refactor: fix internal server errror on bad request

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

@@ -13,6 +13,7 @@ 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.HttpStatusCode;
 import org.springframework.http.ResponseEntity;
 import org.springframework.data.domain.Sort;
 
@@ -26,14 +27,14 @@ import org.springframework.web.bind.annotation.RequestBody;
 public class DatasetController {
     @Autowired
     private DatasetService datasetService;
-    
+
     @GetMapping("/id/{id}")
-    public ResponseEntity<?> getDatasetById(@PathVariable("id") UUID id) {
+    public ResponseEntity<Dataset> getDatasetById(@PathVariable("id") UUID id) {
         Dataset d = datasetService.getDatasetById(id);
         if (d == null) {
             return new ResponseEntity<>(HttpStatus.NOT_FOUND);
         }
-        return new ResponseEntity<>(d , HttpStatus.OK);
+        return new ResponseEntity<>(d, HttpStatus.OK);
     }
 
     @ResponseStatus(HttpStatus.CREATED)
@@ -52,7 +53,7 @@ public class DatasetController {
     }
 
     @PutMapping("/id/{id}/upvote")
-    public ResponseEntity<?> upvote(@PathVariable("id") UUID id) {
+    public ResponseEntity<Dataset> upvote(@PathVariable("id") UUID id) {
         if (datasetService.getDatasetById(id) == null) {
             return new ResponseEntity<>(HttpStatus.NOT_FOUND);
         }
@@ -62,16 +63,16 @@ public class DatasetController {
     }
 
     @PutMapping("/id/{id}/downvote")
-    public ResponseEntity<?> downvote(@PathVariable("id") UUID id) {
+    public ResponseEntity<Dataset> downvote(@PathVariable("id") UUID id) {
         if (datasetService.getDatasetById(id) == null) {
             return new ResponseEntity<>(HttpStatus.NOT_FOUND);
         }
         datasetService.downvoteDataset(id);
-        return new ResponseEntity<>(getDatasetById(id), HttpStatus.OK);
+        return new ResponseEntity<>(datasetService.getDatasetById(id), HttpStatus.OK);
     }
 
     @PutMapping("/id/{id}/vote")
-    public ResponseEntity<?> postMethodName(@PathVariable("id") UUID id,
+    public ResponseEntity<Dataset> postMethodName(@PathVariable("id") UUID id,
             @RequestParam("stars") int stars) {
         if (datasetService.getDatasetById(id) == null) {
             return new ResponseEntity<>(HttpStatus.NOT_FOUND);
@@ -96,22 +97,32 @@ public class DatasetController {
             @RequestParam(value = "direction", required = false, defaultValue = "desc") String direction,
             @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));
+                Sort.by(Sort.Direction.fromString(direction), sort));
         return datasetService.getDatasetsByOptionalCriteria(title, description, author, abst, type, rating, category,
                 pageable);
     }
 
     @GetMapping("/search")
-    public Page<Dataset> search(@RequestParam(value = "search", required = false, defaultValue = "%") String search,
+    public ResponseEntity<Page<Dataset>> search(
+            @RequestParam(value = "search", required = false, defaultValue = "%") String search,
             @RequestParam(value = "page", required = false, defaultValue = "0") int page,
             @RequestParam(value = "size", required = false, defaultValue = "20") int size,
             @RequestParam(value = "sort", required = false, defaultValue = "upvotes") String sort,
             @RequestParam(value = "direction", required = false, defaultValue = "desc") String direction,
             @RequestParam(value = "category", required = false, defaultValue = "%") String category,
             @RequestParam(value = "type", required = false, defaultValue = "%") String type) {
-        Pageable pageable = PageRequest.of(page, size,
+        Pageable pageable = null;
-                Sort.by(direction.equals("asc") ? Sort.Direction.ASC : Sort.Direction.DESC, sort));
+        if (!Dataset.getSort().contains(sort))
-        return datasetService.searchByOptionalCriteria(search, category, type, pageable);
+            return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
+        try {
+            pageable = PageRequest.of(page, size,
+                    Sort.by(Sort.Direction.fromString(direction), sort));
+        } catch (Exception e) {
+            return new ResponseEntity<>(HttpStatus.BAD_REQUEST);
+        }
+
+        return new ResponseEntity<>(datasetService.searchByOptionalCriteria(search, category, type, pageable),
+                HttpStatus.OK);
     }
 
 }

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

@@ -2,6 +2,8 @@ package de.uni_passau.fim.PADAS.group3.DataDash.model;
 
 import java.net.URL;
 import java.time.LocalDate;
+import java.util.Arrays;
+import java.util.List;
 import java.util.UUID;
 import java.sql.Date;
 
@@ -41,6 +43,8 @@ public class Dataset {
 
     private URL url;
 
+    private static final List<String> sortable = Arrays.asList("author", "title", "upvotes", "date");
+
     @ManyToOne
     private Category categorie;
 
@@ -111,6 +115,10 @@ public class Dataset {
         return url;
     }
 
+    public static List<String> getSort() {
+        return sortable;
+    }
+
     public void setAbst(String abst) {
         this.abst = abst.substring(0, Math.min(abst.length(), 100));
     }