Abstract Type mapping in 2.9 fails when multiple modules are registered

[asger82]

If multiple modules are used to map abstract types, deserialization might fail in 2.9+:

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Cannot construct instance of model.Datatype1 (no Creators, like default construct, exist): abstract types either need to be mapped to concrete types, have custom deserializer, or contain additional type information

The bug can be reproduced for version 2.9+ in the attached maven project.

I guess the bug was introduced due to a modification of _mapAbstractType2 in com.fasterxml.jackson.databind.deser.BasicDeserializerFactory:

2.9:
JavaType concrete = resolver.findTypeMapping(config, type);
if (ClassUtil.rawClass(concrete) != currClass) {
return concrete;
}

2.8
if (concrete != null && concrete.getRawClass() != currClass) {
return concrete;
}

The not null check is needed for continuing iterating other modules for abstract type mappings.

jackson-error-example.zip

Best regards
Asger Christiansen

[cowtowncoder]

Thank you for reporting this, providing reproduction. Sounds like bug indeed.

[erdemedeiros]

I'm using this workaround while waiting for 2.9.6:

        SimpleAbstractTypeResolver resolver = new SimpleAbstractTypeResolver(){
            @Override
            public JavaType resolveAbstractType(DeserializationConfig config,
                                                BeanDescription typeDesc) {
                return findTypeMapping(config, typeDesc.getType());
            }
        };
        resolver.addMapping(MyInterface.class,
                            MyImplementation.class);

        module.setAbstractTypes(resolver);