如何使用全局设置强制springboot返回Json响应

Question

Here are problems. They who are testing my application told me that when they trying to directly input the url into address to query a GET url by chrome. My api will always return a XML formatted response like this.

But all the response should be formatted in JSON string ! XML is unacceptable !

I tried to analyze the source code and found request sending by chrome directly will bear attributes like this:

accept= text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng, / ;q=0.8,application/signed-exchange;v=b3;q=0.9
content-type=null

while any other application will send request with:

accept= */* (or accept = application/json)
content-type = application/json

In this case, springboot will then response XML to the request send by chrome because of the missing content-type and specified accept properties.

There is a way to fix this case by excluding jackson for XML in pom. But I don't think it is a graceful way.

So far I refused to fix this problem because I have told Front-end code colleague to send request with specified "application/json" attribute and no problem occured again.

But still, I think I have responsibilities to fix it and there should be ways more graceful to fix this problem.

There are too many api deployed in my application and there is no way to set a response type for every controller. I'm looking for a global setting for this case.

I think there should be some way to act like RequestInterceptor to set headers of a request, but I found that impossible to directly modify the headers from those request in my gateway service.

Help me with this case please. Thanks a lot!

Answer 1

It sounds like you'll want to define a ContentNegotiationCongiurer. Here's a doc: https://www.baeldung.com/spring-mvc-content-negotiation-json-xml

The short answer is to add something like this to the Spring context

@Configuration
public class WebConfig extends WebMvcConfigurerAdapter {
    @Override
    public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
        configurer.defaultContentType(MediaType.APPLICATION_JSON);
    }
}