Spring Jackson custom Deserializer does not called - spring

Question

I have a Spring project, and I try to add a custom deserializer to deserialize Date properties depend on their format.
If I use it as annotation on Date property, it works fine.
But if I add the deserializer to my object mapper, it does not called when Jackson deserialize a date.
I try to apply my custom deserializer like this:
#Bean
public ObjectMapper objectMapper() {
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addDeserializer(Date.class, new DateDeserializer());
mapper.registerModule(module);
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
mapper.configure(DeserializationFeature.FAIL_ON_IGNORED_PROPERTIES, false);
mapper.configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false);
mapper.configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false);
mapper.configure(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES, false);
return mapper;
}
I don't want to apply an annotation on Date properties every time, I want to use this deserializer by default.
What I do wrong?

Answer 1

Thanks the help for everyone.
Finally I found the answer at spring.io.
#Configuration
#EnableWebMvc
public class WebConfiguration extends WebMvcConfigurerAdapter {
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
Jackson2ObjectMapperBuilder builder = new Jackson2ObjectMapperBuilder();
builder.deserializerByType(Date.class, new DateDeserializer());
converters.add(new MappingJackson2HttpMessageConverter(builder.build()));
}
}

Answer 2

Given that if you use the deserializer in an annotation on Date property then I would say that this ObjectMapper is not being used for deserialization. Try the following:
#Bean
public MappingJackson2HttpMessageConverter mappingJackson2HttpMessageConverter(ObjectMapper objectMapper) {
MappingJackson2HttpMessageConverter jsonConverter = new MappingJackson2HttpMessageConverter();
jsonConverter.setObjectMapper(objectMapper);
return jsonConverter;
}

Answer 3

I have doubt how you try to use this ObjectMapper bean inside your application.
I trust you already know that this bean is need to created inside a Configuration class. If not your bean will not register in the context. Like this for example,
#Configuration
public class MapperConfig {
#Bean
public ObjectMapper objectMapper() {
ObjectMapper mapper = new ObjectMapper();
SimpleModule module = new SimpleModule();
module.addDeserializer(Date.class, new DateDeserializer());
mapper.registerModule(module);
mapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
mapper.configure(DeserializationFeature.FAIL_ON_IGNORED_PROPERTIES, false);
mapper.configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false);
mapper.configure(DeserializationFeature.FAIL_ON_INVALID_SUBTYPE, false);
mapper.configure(DeserializationFeature.FAIL_ON_NULL_FOR_PRIMITIVES, false);
return mapper;
}
}
The second problem might be how you try use this ObjectMapper bean. If your create new instance of ObjectMapper like this ObjectMapper objectMapper = new ObjectMapper();, that instance will not have your custom deserializer and stuff. What you can do is #Autowire the ObjectMapper instance that you have already created.