api validation exception handled

src/main/java/com/libraryman_api/exception/GlobalExceptionHandler.java

@@ -2,11 +2,15 @@
 
 import org.springframework.http.HttpStatus;
 import org.springframework.http.ResponseEntity;
+import org.springframework.validation.FieldError;
+import org.springframework.validation.ObjectError;
+import org.springframework.web.bind.MethodArgumentNotValidException;
 import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 import org.springframework.web.context.request.WebRequest;
 
 import java.util.Date;
+import java.util.*;
 
 /**
  * Global exception handler for the LibraryMan API. This class provides
@@ -69,4 +73,18 @@ public ResponseEntity<?> invalidPasswordException(InvalidPasswordException ex, W
         ErrorDetails errorDetails = new ErrorDetails(new Date(), ex.getMessage(), request.getDescription(false));
         return new ResponseEntity<>(errorDetails, HttpStatus.BAD_REQUEST);
     }
+
+    @ExceptionHandler(MethodArgumentNotValidException.class)
+    public ResponseEntity<Map<String,Object>> MethodArgumentNotValidException(MethodArgumentNotValidException ex){
+        List<ObjectError> allErrors = ex.getBindingResult().getAllErrors();
+        HashMap<String,Object> map = new HashMap<>();
+        allErrors.forEach(objectError -> {
+            String message=objectError.getDefaultMessage();
+            String field=((FieldError) objectError).getField();
+            map.put(field,message);
+        });
+
+        return new ResponseEntity<>(map,HttpStatus.BAD_REQUEST);
+    }
+
 }