The best way to update entity in spring boot

August 10, 2022

I’m new to spring boot and trying to make my first api. I’ve made a lot of apis on python using FastAPI framework, but now i decided to study this technology. But here, I met a problem. So I’m using the jpa for database communication and I don’t really understand how to update entity’s fields correctly.

I’ve read a lot of guidelines, and all of them says that updating an entity carried out like this:

    public void updateUserInDatabase(long userId, UserUpdateModel newData) {
        UserEntity user = userRepo.findById(userId).orElseThrow();
        if(newData.getUsername() != null) {
            user.setUsername(newData.getUsername());
        }
        if(newData.getPassword() != null) {
            user.setPassword(newData.getPassword());
        }
    }

But I think it’s not useful as newData can have a lot of fields, so for updating an entity I’ll need a lot of conditions.

So, yeah, maybe this question is silly, but I really try to understand XD. If you know the answer, please tell me! I’d really appreciate it. Thank you in advance.

>Solution :

You could use an entity mapper like MapStruct or ModelMapper

A ModelMapper example:

ModelMapper mapper = new ModelMapper();
// this will tell ModelMapper to ignore null fields when mapping the source (newData) to the destination (user)
mapper.getConfiguration().setSkipNullEnabled(true);

UserEntity user = userRepo.findById(userId).orElseThrow();
// this will tell ModelMapper to map newData into user
mapper.map(newData, user);