REST API java class set initial value of setter getter if no data in database

Question

i have a rest api, i get the data using DAO, mapping it from class to another DTO class, if no data present in database, instead of returning null like this

{
"tes":null,
"tez": null,
"example": null
}

i want to return like this:

{
"tes":"",
"tez": "",
"example": ""
}

i have more than 100 field. so i think its not good to set value in setter getter in all field. how to do this is simple way?

springboot automatically generate json from class in @restcontroller — Vodka, Sep 22 '20 at 14:31

score 0 · Answer 1 · answered Sep 22 '20 at 14:38

As I see you have two options.

Instead of manualy mapping from DAO to DTO Class you need to use a ModelMapper Class with

modelMapper.getConfiguration().setPropertyCondition(Conditions.isNotNull());
As your problem is not clearly the mapping but generating JSON from your DTO, you can use Jackson

@JsonInclude(Include.NON_NULL)

This will skip the empty/null values in your generated JSON.

See: Spring REST Service: how to configure to remove null objects in json response

i dont want to exclude null. i want to change every null to " ". i tried use json include, still get null if no data in database. — Vodka, Sep 22 '20 at 15:27

score 0 · Answer 2 · answered Sep 22 '20 at 14:38

0

You could use Lombok like so

@Builder.Default
private String tes = "my-default-value";

answered Sep 22 '20 at 14:38

rogger2016

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REST API java class set initial value of setter getter if no data in database

2 Answers2