How to find if at least one field is null in a DTO

Question

I work on a Batch with Spring-Batch. In a processor I have to handle a DTO with approximately twenty fields.

Functionally, if no field is empty I have nothing to do. So I would like to find out in first place, if no field is empty.

But I don't really want to do an "if" with twenty

DTO.getValue1 != null && DTO.getValue2 != null [...]

I wonder if there will not be a cleaner way to do that ?

thx in advance.

Change the DTO to expose a collection of its fields (some DTOs do this automatically)? — Dave Newton, Sep 05 '19 at 16:01
If your DTO adheres to JavaBeans specifications check https://stackoverflow.com/questions/3295496/what-is-a-javabean-exactly. — Luca Basso Ricci, Sep 06 '19 at 06:46

score 1 · Accepted Answer · answered Sep 05 '19 at 16:13

You can use reflection for validation purposes. Define an isNull method in the DTO to check for null fields.

public boolean isNull() {
        Field fields[] = this.getClass().getDeclaredFields();
        for (Field f : fields) {
            try {
                Object value = f.get(this);
                if (value != null) {
                    return false;
                }
            }
            catch (IllegalArgumentException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            catch (IllegalAccessException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }


        }
        return true;

    }

Yeah thx functionnaly is more: ```java if (value == null) { return false; } ``` But I have my answer. — M_B, Sep 06 '19 at 09:44

How to find if at least one field is null in a DTO

1 Answers1