Set a variable inside lambda expression [duplicate]

Question

I want to update an entry as following:

public Entry updateEmail(String nom, EntryRequest entryReq) {
        Optional<Entry>  optional =  entryRepository.findByNom(nom);
        Entry updatedEntry = null;
        optional.ifPresent(entry -> {
            if(!StringUtils.isEmpty(entryReq.getEmail())){
                entry.setEmail(entryReq.getEmail());
            }
            updatedEntry = save(entry);
        });
        optional.orElseThrow(() -> new NotFoundException(this.getClass().getName()));
        return updatedEntry;
    }

This code gives me the following error message :

Variable used in lambda expression should be final or effectively final

How can I solve this ?

Antoniossss · Accepted Answer · 2019-01-22 11:40:27Z

3

Just don't use lambda here

Optional<Entry>  optional =  entryRepository.findByNom(nom);
Entry updatedEntry = null;
if(optional.isPresent()){
    Entry entry=optional.get();
    if(!StringUtils.isEmpty(entryReq.getEmail())){
        entry.setEmail(entryReq.getEmail());
    }
    updatedEntry = save(entry);
});
optional.orElseThrow(() -> new NotFoundException(this.getClass().getName()));
return updatedEntry;

or even better

Optional<Entry>  optional =  entryRepository.findByNom(nom);
Entry entry=optional.orElseThrow(() -> new NotFoundException(this.getClass().getName()));
    if(!StringUtils.isEmpty(entryReq.getEmail())){
        entry.setEmail(entryReq.getEmail());
    } 
return save(entry);

answered Jan 22, 2019 at 11:40

Antoniossss

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Comments

gil.fernandes · Accepted Answer · 2019-01-22 12:44:49Z

You can actually use the map method of Optional to process the save in case the initial entry exists:

public Entry updateEmail(String nom, EntryRequest entryReq) {
    Optional<Entry>  optional =  entryRepository.findByNom(nom);
    Entry updatedEntry = optional.map(entry -> {
        if(!StringUtils.isEmpty(entryReq.getEmail())){
            entry.setEmail(entryReq.getEmail());
        }
        return save(entry);
    }).orElseThrow(() -> new NotFoundException(this.getClass().getName()));
    return updatedEntry;
}

A bit more concisely:

public Entry updateEmail(String nom, EntryRequest entryReq) {
    Optional<Entry>  optional =  entryRepository.findByNom(nom);
    return optional.map(entry -> {
        if(!StringUtils.isEmpty(entryReq.getEmail())){
            entry.setEmail(entryReq.getEmail());
        }
        return save(entry);
    }).orElseThrow(() -> new NotFoundException(this.getClass().getName()));
}

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