👀 Views: 76 💬 Answers: 1 📅 Created: 2025-06-18

spring-boot rest http content-negotiation Java

I'm wondering if anyone has experience with I'm refactoring my project and I'm working with scenarios with content negotiation in my Spring Boot REST API, particularly when clients request different media types. I have set up my API to respond with JSON by default, but I'm working with instances where the API does not respect the `Accept` header sent by clients. For example, when a client sends an `Accept: application/xml` header, the response still comes back as JSON instead of XML. I have the following configuration in my `WebMvcConfigurer`: ```java @Configuration public class WebConfig implements WebMvcConfigurer { @Override public void configureMessageConverters(List<HttpMessageConverter<?>> converters) { converters.add(new MappingJackson2HttpMessageConverter()); converters.add(new MarshallingHttpMessageConverter()); } } ``` However, even with the `MarshallingHttpMessageConverter` included, the response type doesn’t change when I specify `Accept: application/xml`. I also tried using `@RequestMapping` annotations with produces attribute: ```java @RestController @RequestMapping(value = "/api", produces = {"application/json", "application/xml"}) public class MyController { @GetMapping("/data") public MyData getData() { return new MyData(); } } ``` Despite these configurations, clients consistently receive JSON instead of XML. I’m also seeing the following warning in my logs: `WARNING: No suitable HttpMessageConverter found for response type [application/xml]`. Can someone guide to understand why the content negotiation isn't functioning as expected? Are there additional configurations I might be missing, or is there a common pitfall in configuring message converters in Spring Boot? I'm using Spring Boot 2.5.4 and Jackson 2.12.3. This is for a application running on Ubuntu 22.04. What's the best practice here? This is happening in both development and production on Windows 11. Any advice would be much appreciated.