```java;gutter:true;
If put on a parameter, lombok will insert a null-check at the start of the method / constructor's body, throwing a {@code NullPointerException} with the parameter's name as message. If put on a field, any generated method assigning a value to this field will also produce these null-checks.
```
可见 @NonNull 注解用于标注Field时，并非是直接校验所标注字段不能为空，而是对赋值该字段的方法加 null 校验。
如该对象
```java;gutter:true;
@Data
@AllArgsConstructor
public class ReqIn {
@NonNull
private Byte name;
private String id;
public ReqIn(){