Design idea of initializing page input parameters

Recently, I am refactoring old code , In the process of writing, it is found that if the previous logic encounters no input parameters pageNo Meeting Npe, So I want to find out how to deal with the company's projects page There are two types of participants as follows

1. Use ternary expressions to directly determine whether null, Then assign a value
2. Use mapStruct Assignment initialization AO

But I think both of them are a little troublesome , What I want is to generate and initialize on demand page Parameters are good , So we have the following design

Create a new BaseDTO Used to be inherited

@Data
public class BasePageDTO {
    
    private Integer pageNo;
    private Integer pageSize;
}

Put your dto Inherit this BaseDTO, Because the code specification stipulates that bean It directly assigns the default value of the attribute , So our dto In succession BasePageDTO It needs one step of processing , I have a new one PageUtil Tool class , The code is as follows

@Component
public class PageUtil {
    

    public static void buildPage(BasePageDTO pageDTO){
    
        if (Objects.isNull(pageDTO.getPageNo())){
    
            pageDTO.setPageNo(1);
        }
        if (Objects.isNull(pageDTO.getPageSize())){
    
            pageDTO.setPageSize(20);
        }
    }
}

Finally, I need to initialize page Call this method directly when setting parameters ,page Parameters are fine