While we were building our RESTful web data service, we defined the controllers, repositories, and put some annotations on them; but nowhere did we do any kind of object translation from the java entity beans to the HTTP data stream output. However, behind the scenes, Spring Boot automatically configured HttpMessageConverters to translate our entity beans objects into a JSON representation using Jackson library, writing the resulting JSON data to an HTTP response output stream. When multiple converters are available, the most applicable one gets selected based on the message object class and the requested content type.

The purpose of HttpMessageConverters is to translate various object types into their corresponding HTTP output formats. A converter can either support a range of multiple data types or multiple output formats, or a combination of both. For example, MappingJackson2HttpMessageConverter can translate any Java Object into application/json...