ServletWebRequest.getHeaderValues throwing NPE when header information is not available

[ketsorbit]

in ServletWebRequest class -> getHeaderValues() method:

getRequest().getHeaders(headerName) may return null .. and so, StringUtils.tostringArray() throws Null Pointer Exception.

[wilkinsona]

Can you please share the stack trace of the exception? ServletWebRequest is part of Spring Framework so the problem may need to be fixed there rather than in Spring Boot.

[spring-projects-issues]

If you would like us to look at this issue, please provide the requested information. If the information is not provided within the next 7 days this issue will be closed.

[ketsorbit]

Hi,
Sorry for the delay !

Here's the stacktrace:

java.lang.NullPointerException
java.util.Collections.list(Collections.java:5239)
org.springframework.util.StringUtils.toStringArray(StringUtils.java:980)
org.springframework.web.context.request.ServletWebRequest.getHeaderValues(ServletWebRequest.java:143)
org.springframework.web.accept.HeaderContentNegotiationStrategy.resolveMediaTypes(HeaderContentNegotiationStrategy.java:46)
org.springframework.web.accept.ContentNegotiationManager.resolveMediaTypes(ContentNegotiationManager.java:124)
org.springframework.web.servlet.mvc.condition.ProducesRequestCondition.getAcceptedMediaTypes(ProducesRequestCondition.java:262)
org.springframework.web.servlet.mvc.condition.ProducesRequestCondition.getMatchingCondition(ProducesRequestCondition.java:199)
org.springframework.web.servlet.mvc.method.RequestMappingInfo.getMatchingCondition(RequestMappingInfo.java:223)
org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.getMatchingMapping(RequestMappingInfoHandlerMapping.java:93)
org.springframework.web.servlet.mvc.method.RequestMappingInfoHandlerMapping.getMatchingMapping(RequestMappingInfoHandlerMapping.java:57)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.addMatchingMappings(AbstractHandlerMethodMapping.java:428)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.lookupHandlerMethod(AbstractHandlerMethodMapping.java:390)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:368)
org.springframework.web.servlet.handler.AbstractHandlerMethodMapping.getHandlerInternal(AbstractHandlerMethodMapping.java:65)
org.springframework.web.servlet.handler.AbstractHandlerMapping.getHandler(AbstractHandlerMapping.java:401)
org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1231)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1014)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:942)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1005)
org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:897)
javax.servlet.http.HttpServlet.service(HttpServlet.java:635)

[philwebb]

This looks like a framework bug so I've transferred the issue.

[jhoeller]

A null return value is defined to only happen if "the container does not allow access to header information" according to the HttpServletRequest javadoc... In any case, we should handle this defensively.

[jhoeller]

This turns out to be a regression from 4.3.x, introduced during our 5.0 nullability revision of StringUtils.