Spring Server Error on unknown Accept header - spring

Question

I have a Spring REST project that uses spring boot. I have declared jackson-dataformat-xml as a dependency in maven to support xml when the accept header is application/xml (and it natively accepts application/json).
The problem I have is when i set the accept header to anything other than those two (ex application/dsfas or text/html, I get a server error with the following exception:
23:36:04.368 [http-nio-8082-exec-5] WARN o.s.w.s.m.m.a.ExceptionHandlerExceptionResolver - Failure in #ExceptionHandler protected org.springframework.http.ResponseEntity<java.lang.Object> com.mergg.common.web.RestResponseEntityExceptionHandler.handleNotFound(java.lang.RuntimeException,org.springframework.web.context.request.WebRequest)
org.springframework.web.HttpMediaTypeNotAcceptableException: Could not find acceptable representation
Any idea on how to fix so that I can either ignore the accept header and return json or tell the client it was a bad request?

Answer 1

public class JsonContentNegotiation implements ContentNegotiationStrategy {
#Override
public List<MediaType> resolveMediaTypes(NativeWebRequest webRequest) throws HttpMediaTypeNotAcceptableException {
System.out.println("This is your negotation Strategy");
HttpServletRequest request = webRequest.getNativeRequest(HttpServletRequest.class);
String headers = request.getHeader(HttpHeaders.ACCEPT);
List<MediaType> mediaTypes = MediaType.parseMediaTypes(headers);
if(headers.indexOf(MediaType.APPLICATION_JSON_VALUE)==-1){
mediaTypes.add(new MediaType("application","json"));
}
MediaType.sortBySpecificityAndQuality(mediaTypes);
return mediaTypes;
}
}
<bean id="contentNegotiationManager" class="org.springframework.web.accept.ContentNegotiationManagerFactoryBean">
<property name="favorPathExtension" value="true"/>
<property name="ignoreAcceptHeader" value="true"/>
<property name="defaultContentTypeStrategy">
<bean class="demo2.ContentNegotation.JsonContentNegotiation"/>
</property>
<mvc:annotation-driven content-negotiation-manager="contentNegotiationManager"/>
otherwise use this in the controller to tell the client this is wrong header
#ExceptionHandler({HttpMediaTypeNotAcceptableException.class})
#ResponseBody
public String fix(Exception e){
System.out.println("do This");
return "Accept Header may be wrong";
}