@jsonview fail on unknown properties

Question

I need to use @JsonView for throwing Exceptions while deserialization.

My POJO:

public class Contact
{
    @JsonView( ContactViews.Person.class )
    private String personName;

    @JsonView( ContactViews.Company.class )
    private String companyName;
}

My Service:

public static Contact createPerson(String json) {

    ObjectMapper mapper = new ObjectMapper().configure( DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES , true );

    Contact person = mapper.readerWithView( ContactViews.Person.class ).forType( Contact.class ).readValue( json );

    return person;
}


public static Contact createCompany(String json) {

    ObjectMapper mapper = new ObjectMapper().configure( DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES , true );

    Contact company = mapper.readerWithView( ContactViews.Company.class ).forType( Contact.class ).readValue( json );

    return company;
}

What I need to achieve is that, if I am trying to create a Person, I need to pass only 'personName'. If I pass 'companyName', I need to throw exception. How can I achieve this with @JsonView? Is there any alternative?

Answer 1

I think @JsonView is not enough to solve this for you. Here is more info why: UnrecognizedPropertyException is not thrown when deserializing properties that are not part of the view

But i just looked in source code and managed to kinda "hack" this issue with combination of @JsonView and custom BeanDeserializerModifier. It'is not pretty, but here is essential part:

public static class MyBeanDeserializerModifier extends BeanDeserializerModifier {

    @Override
    public BeanDeserializerBuilder updateBuilder(DeserializationConfig config, 
                     BeanDescription beanDesc, BeanDeserializerBuilder builder) {
        if (beanDesc.getBeanClass() != Contact.class) {
            return builder;
        }

        List<PropertyName> properties = new ArrayList<>();
        Iterator<SettableBeanProperty> beanPropertyIterator = builder.getProperties();
        Class<?> activeView = config.getActiveView();


        while (beanPropertyIterator.hasNext()) {
            SettableBeanProperty settableBeanProperty = beanPropertyIterator.next();
            if (!settableBeanProperty.visibleInView(activeView)) {
                properties.add(settableBeanProperty.getFullName());
            }
        }

        for(PropertyName p : properties){
            builder.removeProperty(p);
        }

        return builder;
    }
}

and here is how you register it on your object mapper:

ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.setDeserializerModifier(new MyBeanDeserializerModifier());
mapper.registerModule(module);

This works for me and i'm getting UnrecognizedPropertyException now:

com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "companyName" (class Main2$Contact), not marked as ignorable (one known property: "personName"])