java - Spring Boot 的 WelcomePageHandlerMapping 在无效的 API 路径上被调用，其中预期出现 404 错误

Question

我有一个简单的 Spring Boot (3.1.2) 应用程序，其中定义了 @RestController 和多个 @GetMapping(/app/test、/app/test2)。

例如:

@GetMapping("/test")
    public TestModel getTestModel() {
        return TestModel.builder()
                .testModelName("The best test model ever!")
                .testModelVersion(1)
                .build();
    }

因此，当我尝试使用不正确的 API 路径和 Accept header 向我的应用程序发送请求时，如下所示:

curl -X GET http://localhost:8080/random/in Correct -H“接受:yaml”

我收到了以下异常，而不是预期的 404 Not Found 错误:

jakarta.servlet.ServletException: Request processing failed: org.springframework.http.InvalidMediaTypeException: Invalid mime type "yaml": does not contain '/'
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1019) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:500) ~[jakarta.servlet-api-5.0.0.jar:5.0.0]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:587) ~[jakarta.servlet-api-5.0.0.jar:5.0.0]
    at org.eclipse.jetty.servlet.ServletHolder.handle(ServletHolder.java:764) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler$ChainEnd.doFilter(ServletHandler.java:1665) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) ~[spring-web-6.0.11.jar:6.0.11]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:202) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1635) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) ~[spring-web-6.0.11.jar:6.0.11]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:202) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1635) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) ~[spring-web-6.0.11.jar:6.0.11]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116) ~[spring-web-6.0.11.jar:6.0.11]
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:202) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1635) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.websocket.servlet.WebSocketUpgradeFilter.doFilter(WebSocketUpgradeFilter.java:170) ~[websocket-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.FilterHolder.doFilter(FilterHolder.java:202) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler$Chain.doFilter(ServletHandler.java:1635) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:527) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:131) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.security.SecurityHandler.handle(SecurityHandler.java:578) ~[jetty-security-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:223) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.session.SessionHandler.doHandle(SessionHandler.java:1570) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ScopedHandler.nextHandle(ScopedHandler.java:221) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1381) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:176) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:484) ~[jetty-servlet-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.session.SessionHandler.doScope(SessionHandler.java:1543) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ScopedHandler.nextScope(ScopedHandler.java:174) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1303) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:129) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:122) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.Server.handle(Server.java:563) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.HttpChannel.lambda$handle$0(HttpChannel.java:505) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.HttpChannel.dispatch(HttpChannel.java:762) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:497) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:282) ~[jetty-server-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.io.AbstractConnection$ReadCallback.succeeded(AbstractConnection.java:314) ~[jetty-io-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.io.FillInterest.fillable(FillInterest.java:100) ~[jetty-io-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.io.SelectableChannelEndPoint$1.run(SelectableChannelEndPoint.java:53) ~[jetty-io-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:969) ~[jetty-util-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.doRunJob(QueuedThreadPool.java:1194) ~[jetty-util-11.0.15.jar:11.0.15]
    at org.eclipse.jetty.util.thread.QueuedThreadPool$Runner.run(QueuedThreadPool.java:1149) ~[jetty-util-11.0.15.jar:11.0.15]
    at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]
Caused by: org.springframework.http.InvalidMediaTypeException: Invalid mime type "yaml": does not contain '/'
    at org.springframework.http.MediaType.parseMediaType(MediaType.java:742) ~[spring-web-6.0.11.jar:6.0.11]
    at org.springframework.http.MediaType.parseMediaTypes(MediaType.java:768) ~[spring-web-6.0.11.jar:6.0.11]
    at org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping.getAcceptedMediaTypes(WelcomePageHandlerMapping.java:82) ~[spring-boot-autoconfigure-3.1.2.jar:3.1.2]
    at org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping.isHtmlTextAccepted(WelcomePageHandlerMapping.java:71) ~[spring-boot-autoconfigure-3.1.2.jar:3.1.2]
    at org.springframework.boot.autoconfigure.web.servlet.WelcomePageHandlerMapping.getHandlerInternal(WelcomePageHandlerMapping.java:67) ~[spring-boot-autoconfigure-3.1.2.jar:3.1.2]
    at org.springframework.web.servlet.handler.AbstractHandlerMapping.getHandler(AbstractHandlerMapping.java:505) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at org.springframework.web.servlet.DispatcherServlet.getHandler(DispatcherServlet.java:1275) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1057) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974) ~[spring-webmvc-6.0.11.jar:6.0.11]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011) ~[spring-webmvc-6.0.11.jar:6.0.11]
    ... 48 common frames omitted

正如我所看到的，WelcomePageHandlerMapping 正在被调用。所以我的问题是:为什么这个处理程序被调用而不是立即返回 404 错误？

我试图在文档中查找一些信息，但没有成功。

Answer 1

当收到请求时，Spring MVC 按顺序调用所有已注册的处理程序映射，直到为该请求提供处理程序为止。

WelcomePageHandlerMapping 在 RequestMappingHandlerMapping 之后排序，因此仅当没有 @RequestMapping 与请求匹配时才会调用 WelcomePageHandlerMapping .

当调用 WelcomePageHandlerMapping 时，它必须确定是否可以为传入请求提供处理程序。确定是否可以这样做的一部分是检查请求是否接受 text/html 响应。此检查是在检查路径是否匹配之前完成的，因此无论请求的路径如何，无效的 Accept header 都会导致问题。