уникальное поле чтоб пресечь двойное добавление випа

src/main/java/app/controllers/other/ExternalVIPController.java

@@ -14,14 +14,19 @@ import org.springframework.web.bind.annotation.RequestMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
+import java.util.HashSet;
+
 @RestController
 @RequestMapping("api/external/vip")
 public class ExternalVIPController {
     VIPService vipService;
 
+    HashSet<String> unique_set;
+
     @Autowired
     public ExternalVIPController(VIPService vipService) {
         this.vipService = vipService;
+        this.unique_set = new HashSet();
     }
 
     @PostMapping
@@ -30,7 +35,14 @@ public class ExternalVIPController {
                                  @RequestParam String steam,
                                  @RequestParam int amount,
                                  @RequestParam String service,
-                                 @RequestParam(required = false, defaultValue = "") String extra) {
+                                 @RequestParam(required = false, defaultValue = "") String extra,
+                                 @RequestParam(required = false, defaultValue = "") String unique) {
+
+        if (!unique.isEmpty()) {
+            if (unique_set.contains(unique)) return new ResponseEntity(HttpStatus.NOT_ACCEPTABLE);
+            else unique_set.add(unique);
+        }
+
         int result = vipService.addVIP(
                 SteamIDConverter.getSteamID(steam),
                 amount,