feat: upgrade user management demo

src/main/java/com/example/demo/dto/UserRequest.java

@@ -4,16 +4,21 @@ import jakarta.validation.constraints.Email;
 import jakarta.validation.constraints.Max;
 import jakarta.validation.constraints.Min;
 import jakarta.validation.constraints.NotBlank;
+import jakarta.validation.constraints.NotNull;
+import jakarta.validation.constraints.Size;
 
 public record UserRequest(
-        @NotBlank(message = "姓名不能为空")
+        @NotBlank(message = "Name is required")
+        @Size(max = 40, message = "Name must be at most 40 characters")
         String name,
 
-        @NotBlank(message = "邮箱不能为空")
-        @Email(message = "邮箱格式不正确")
+        @NotBlank(message = "Email is required")
+        @Email(message = "Email format is invalid")
         String email,
 
-        @Min(value = 1, message = "年龄最小为 1")
-        @Max(value = 120, message = "年龄最大为 120")
+        @NotNull(message = "Age is required")
+        @Min(value = 1, message = "Age must be at least 1")
+        @Max(value = 120, message = "Age must be at most 120")
         Integer age
-) {}
+) {
+}