MvcConfig.java

import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.databind.SerializationFeature;

...

import org.springframework.http.converter.HttpMessageConverter;
import org.springframework.http.converter.json.Jackson2ObjectMapperBuilder;
import org.springframework.http.converter.json.MappingJackson2HttpMessageConverter;

@Configuration
@EnableWebMvc
public class MvcConfig implements WebMvcConfigurer {

  ...

  @Override
  public void extendMessageConverters(final List<HttpMessageConverter<?>> converters) {
    ObjectMapper objectMapper = Jackson2ObjectMapperBuilder
        .json()
        .featuresToDisable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS)
        .build();
    converters.add(0, new MappingJackson2HttpMessageConverter(objectMapper));
  }

}