Jackson Dynamic filtering of properties during deserialization

Question

I have a REST WS to update a bean object which receives a JSON string as input.

ABean entity = svc.findEntity(...);
objectMapper.readerForUpdating(entity).r         


        

Answer 1

Another way is using BeanDeserializerModifier:

private static class BeanDeserializerModifierForIgnorables extends BeanDeserializerModifier {

        private java.lang.Class type;
        private List ignorables;

        public BeanDeserializerModifierForIgnorables(java.lang.Class clazz, String... properties) {
            ignorables = new ArrayList<>();
            for(String property : properties) {
                ignorables.add(property);
            }
            this.type = clazz;
        }

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

            for(String ignorable : ignorables) {
                builder.addIgnorable(ignorable);                
            }

            return builder;
        }

        @Override
        public List updateProperties(
                DeserializationConfig config, BeanDescription beanDesc,
                List propDefs) {
            if(!type.equals(beanDesc.getBeanClass())) {
                return propDefs;
            }

            List newPropDefs = new ArrayList<>();
            for(BeanPropertyDefinition propDef : propDefs) {
                if(!ignorables.contains(propDef.getName())) {
                    newPropDefs.add(propDef);
                }
            }
            return newPropDefs;
        }
    }

You can register the modfier to the ObjectMapper with:

BeanDeserializerModifier modifier = new BeanDeserializerModifierForIgnorables(YourType.class, "name");
DeserializerFactory dFactory = BeanDeserializerFactory.instance.withDeserializerModifier(modifier);
ObjectMapper mapper = new ObjectMapper(null, null, new DefaultDeserializationContext.Impl(dFactory));

Then the defined properties are ignored. You can ignore the updateBuilder method if you use the @JsonAnySetter annotation.

Greetings, Martin