Set a different ObjectMapper for the specific Spring MVC package

Question

Is there a way to install HttpMessageConverter only for specific packages in my project using spring?

@Configuration @EnableWebMvc @ComponentScan(basePackageClasses = MyConfig.class) public class MyConfig extends WebMvcConfigurerAdapter { @Override public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { for (HttpMessageConverter<?> converter : converters) { if (converter instanceof MappingJacksonHttpMessageConverter) { ObjectMapper objectMapper = new ObjectMapper(); objectMapper.configure(DeserializationConfig.Feature.FAIL_ON_UNKNOWN_PROPERTIES, false); objectMapper.setPropertyNamingStrategy(PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES); objectMapper.setSerializationInclusion(Inclusion.NON_NULL); ((MappingJacksonHttpMessageConverter) converter).setObjectMapper(objectMapper); } } } 

Using this PropertyNamingStrategy.CAMEL_CASE_TO_LOWER_CASE_WITH_UNDERSCORES , changes all the answers in the project, and I want this to apply only in some dto.

Answer 1

Here's an example solution offered by hzpz:

Custom Converter:

 public class CustomConverter extends MappingJackson2HttpMessageConverter { private String basePackage; public CustomConverter(String basePackage) { this.basePackage = basePackage; } @Override public boolean canRead(Type type, Class<?> contextClass, MediaType mediaType) { if (contextClass.getName().startsWith(basePackage)) { return super.canRead(type, contextClass, mediaType); } return false; } @Override public boolean canWrite(Class<?> clazz, MediaType mediaType) { if (clazz.getName().startsWith(basePackage)) { return super.canWrite(clazz, mediaType); } return false; } } 

Configuration

 @Configuration public class CustomConfig { @Bean public MappingJackson2HttpMessageConverter firstConverter() { MappingJackson2HttpMessageConverter converter = new CustomConverter("package.camel"); converter.setObjectMapper(firstObjectMapper()); return converter; } @Bean public MappingJackson2HttpMessageConverter secondConverter() { MappingJackson2HttpMessageConverter converter = new CustomConverter("package.snake"); converter.setObjectMapper(secondObjectMapper()); return converter; } @Bean public ObjectMapper firstObjectMapper() { ObjectMapper mapper = new ObjectMapper(); mapper.setPropertyNamingStrategy(PropertyNamingStrategy.LOWER_CAMEL_CASE); return mapper; } @Bean public ObjectMapper secondObjectMapper() { ObjectMapper mapper = new ObjectMapper(); mapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE); return mapper; } }