feature: 사이즈 API 수정

src/main/java/zip/ootd/ootdzip/category/controller/SizeController.java

@@ -4,9 +4,11 @@
 
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import io.swagger.v3.oas.annotations.tags.Tag;
+import jakarta.validation.Valid;
 import lombok.RequiredArgsConstructor;
 import zip.ootd.ootdzip.category.data.SizeReq;
 import zip.ootd.ootdzip.category.data.SizeRes;
@@ -20,8 +22,8 @@ public class SizeController {
 
     private final SizeService sizeService;
 
-    @GetMapping("/")
-    public List<SizeRes> findByCategory(SizeReq request) {
+    @GetMapping("")
+    public List<SizeRes> findByCategory(@Valid @RequestParam SizeReq request) {
         return sizeService.findByCategory(request);
     }
 }

src/main/java/zip/ootd/ootdzip/category/data/SizeReq.java

@@ -1,9 +1,11 @@
 package zip.ootd.ootdzip.category.data;
 
+import jakarta.validation.constraints.Positive;
 import lombok.Data;
 
 @Data
 public class SizeReq {
 
+    @Positive(message = "카테고리 ID는 양수여야 한다.")
     private Long categoryId;
 }