Overhaul the mappings endpoint

[wilkinsona]

The mappings endpoint is currently described as returning "a collated list of all @RequestMapping paths". It actually returns more than that as it introspects any AbstractUrlHandlerMapping and AbstractHandlerMethodMapping instances, not just those that are associated with @RequestMapping. However, there are some mappings that it doesn't currently return such as those configured by Spring Data REST.

Beyond the accuracy of the description, the content of the response is a little haphazard. It currently looks like this:

{
    "/**": {
        "bean": "resourceHandlerMapping"
    },
    "/**/favicon.ico": {
        "bean": "faviconHandlerMapping"
    },
    "/webjars/**": {
        "bean": "resourceHandlerMapping"
    },
    "{[/application/auditevents],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}": {
        "bean": "webEndpointServletHandlerMapping",
        "method": "public java.lang.Object org.springframework.boot.endpoint.web.mvc.WebEndpointServletHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)"
    },
    "{[/application/autoconfig],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}": {
        "bean": "webEndpointServletHandlerMapping",
        "method": "public java.lang.Object org.springframework.boot.endpoint.web.mvc.WebEndpointServletHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)"
    },
    "{[/application/beans],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}": {
        "bean": "webEndpointServletHandlerMapping",
        "method": "public java.lang.Object org.springframework.boot.endpoint.web.mvc.WebEndpointServletHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)"
    }
    // …
}

The keys in the map are just the toString() of the mapping object which can, essentially, be anything. As such, there's no guarantee of the format of the key. There's also, as far as I know, no guarantee that the keys will be unique across everything that's introspected so entries in the map may clash. Lastly, handler mappings are ordered and this ordering is lost by using a map.

We also need to figure out what, if anything, we want to do for WebFlux and Jersey. Perhaps they should be completely separate endpoints? However, if you're using a combination of MVC and Jersey it might be nice to have all mappings available from a single source.

[wilkinsona]

I've opened some Framework issues that all relate to this:

• SPR-15933
• SPR-15934
• SPR-15935

[wilkinsona]

Let's try and also include information about Filters and Servlets too (previously tracked by #2178).

[wilkinsona]

Here's an example of a what the response might look like for an app using Spring MVC and Spring Data REST:

{
    "dispatcherServlets": {
        "dispatcherServlet": [
            {
                "handler": "ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/], ServletContext resource [/], class path resource []], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@20de1a03]]",
                "predicate": "/**/favicon.ico"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/auditevents],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/beans],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/autoconfig],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/configprops],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/env/{toMatch}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/env],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/health],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/status],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/info],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/loggers],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/loggers/{name}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/loggers/{name}],methods=[POST],consumes=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/threaddump],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/metrics/{requiredMetricName}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/metrics],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/trace],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/mappings],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public java.lang.Object org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping$OperationHandler.handle(javax.servlet.http.HttpServletRequest,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/heapdump],methods=[GET],produces=[application/octet-stream]}"
            },
            {
                "handler": "private java.util.Map<java.lang.String, java.util.Map<java.lang.String, org.springframework.boot.actuate.endpoint.web.Link>> org.springframework.boot.actuate.endpoint.web.servlet.WebMvcEndpointHandlerMapping.links(javax.servlet.http.HttpServletRequest)",
                "predicate": "{[/application],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)",
                "predicate": "{[/error]}"
            },
            {
                "handler": "public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)",
                "predicate": "{[/error],produces=[text/html]}"
            },
            {
                "handler": "org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.alps.AlpsController.alpsOptions()",
                "predicate": "{[/api/profile/{repository}],methods=[OPTIONS],produces=[application/alps+json]}"
            },
            {
                "handler": "org.springframework.http.HttpEntity<org.springframework.data.rest.webmvc.RootResourceInformation> org.springframework.data.rest.webmvc.alps.AlpsController.descriptor(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/profile/{repository}],methods=[GET],produces=[application/alps+json || */*]}"
            },
            {
                "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.ProfileController.profileOptions()",
                "predicate": "{[/api/profile],methods=[OPTIONS]}"
            },
            {
                "handler": "org.springframework.http.HttpEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.ProfileController.listAllFormsOfMetadata()",
                "predicate": "{[/api/profile],methods=[GET]}"
            },
            {
                "handler": "public org.springframework.http.HttpEntity<org.springframework.data.rest.webmvc.json.JsonSchema> org.springframework.data.rest.webmvc.RepositorySchemaController.schema(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/profile/{repository}],methods=[GET],produces=[application/schema+json]}"
            },
            {
                "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.RepositoryController.optionsForRepositories()",
                "predicate": "{[/api/ || /api],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryController.headForRepositories()",
                "predicate": "{[/api/ || /api],methods=[HEAD],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.HttpEntity<org.springframework.data.rest.webmvc.RepositoryLinksResource> org.springframework.data.rest.webmvc.RepositoryController.listRepositories()",
                "predicate": "{[/api/ || /api],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.optionsForCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/{repository}],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.headCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.support.DefaultedPageable) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}],methods=[HEAD],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.hateoas.Resources<?> org.springframework.data.rest.webmvc.RepositoryEntityController.getCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws org.springframework.data.rest.webmvc.ResourceNotFoundException,org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.hateoas.Resources<?> org.springframework.data.rest.webmvc.RepositoryEntityController.getCollectionResourceCompact(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws org.springframework.data.rest.webmvc.ResourceNotFoundException,org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}],methods=[GET],produces=[application/x-spring-data-compact+json || text/uri-list]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryEntityController.postCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.PersistentEntityResource,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,java.lang.String) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}],methods=[POST],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.optionsForItemResource(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/{repository}/{id}],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.headForItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}/{id}],methods=[HEAD],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.Resource<?>> org.springframework.data.rest.webmvc.RepositoryEntityController.getItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.http.HttpHeaders) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}/{id}],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<? extends org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryEntityController.putItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.PersistentEntityResource,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.data.rest.webmvc.support.ETag,java.lang.String) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}/{id}],methods=[PUT],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryEntityController.patchItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.PersistentEntityResource,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.data.rest.webmvc.support.ETag,java.lang.String) throws org.springframework.web.HttpRequestMethodNotSupportedException,org.springframework.data.rest.webmvc.ResourceNotFoundException",
                "predicate": "{[/api/{repository}/{id}],methods=[PATCH],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.deleteItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,org.springframework.data.rest.webmvc.support.ETag) throws org.springframework.data.rest.webmvc.ResourceNotFoundException,org.springframework.web.HttpRequestMethodNotSupportedException",
                "predicate": "{[/api/{repository}/{id}],methods=[DELETE],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.data.rest.webmvc.RepositorySearchesResource org.springframework.data.rest.webmvc.RepositorySearchController.listSearches(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/{repository}/search],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.RepositorySearchController.optionsForSearches(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/{repository}/search],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.RepositorySearchController.headForSearches(org.springframework.data.rest.webmvc.RootResourceInformation)",
                "predicate": "{[/api/{repository}/search],methods=[HEAD],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositorySearchController.executeSearch(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.util.MultiValueMap<java.lang.String, java.lang.Object>,java.lang.String,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.http.HttpHeaders)",
                "predicate": "{[/api/{repository}/search/{search}],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.hateoas.ResourceSupport org.springframework.data.rest.webmvc.RepositorySearchController.executeSearchCompact(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.http.HttpHeaders,org.springframework.util.MultiValueMap<java.lang.String, java.lang.Object>,java.lang.String,java.lang.String,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler)",
                "predicate": "{[/api/{repository}/search/{search}],methods=[GET],produces=[application/x-spring-data-compact+json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<java.lang.Object> org.springframework.data.rest.webmvc.RepositorySearchController.optionsForSearch(org.springframework.data.rest.webmvc.RootResourceInformation,java.lang.String)",
                "predicate": "{[/api/{repository}/search/{search}],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<java.lang.Object> org.springframework.data.rest.webmvc.RepositorySearchController.headForSearch(org.springframework.data.rest.webmvc.RootResourceInformation,java.lang.String)",
                "predicate": "{[/api/{repository}/search/{search}],methods=[HEAD],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.followPropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,java.lang.String,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws java.lang.Exception",
                "predicate": "{[/api/{repository}/{id}/{property}/{propertyId}],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.followPropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws java.lang.Exception",
                "predicate": "{[/api/{repository}/{id}/{property}],methods=[GET],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<? extends org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.deletePropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String) throws java.lang.Exception",
                "predicate": "{[/api/{repository}/{id}/{property}],methods=[DELETE],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.followPropertyReferenceCompact(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws java.lang.Exception",
                "predicate": "{[/api/{repository}/{id}/{property}],methods=[GET],produces=[application/x-spring-data-compact+json || text/uri-list]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<? extends org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.createPropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.http.HttpMethod,org.springframework.hateoas.Resources<java.lang.Object>,java.io.Serializable,java.lang.String) throws java.lang.Exception",
                "predicate": "{[/api/{repository}/{id}/{property}],methods=[PATCH || PUT || POST],consumes=[application/json || application/x-spring-data-compact+json || text/uri-list],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.deletePropertyReferenceId(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,java.lang.String) throws java.lang.Exception",
                "predicate": "{[/api/{repository}/{id}/{property}/{propertyId}],methods=[DELETE],produces=[application/hal+json || application/json]}"
            },
            {
                "handler": "ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/webjars/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@652dcdbd]]",
                "predicate": "/webjars/**"
            },
            {
                "handler": "ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/], ServletContext resource [/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@3573cd19]]",
                "predicate": "/**"
            }
        ]
    },
    "servletFilters": [
        {
            "className": "org.springframework.boot.web.servlet.filter.OrderedRequestContextFilter",
            "name": "requestContextFilter",
            "servletNameMappings": [],
            "urlPatternMappings": [
                "/*"
            ]
        },
        {
            "className": "org.apache.tomcat.websocket.server.WsFilter",
            "name": "Tomcat WebSocket (JSR356) Filter",
            "servletNameMappings": [],
            "urlPatternMappings": [
                "/*"
            ]
        },
        {
            "className": "org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter",
            "name": "httpPutFormContentFilter",
            "servletNameMappings": [],
            "urlPatternMappings": [
                "/*"
            ]
        },
        {
            "className": "org.springframework.boot.web.servlet.filter.OrderedHiddenHttpMethodFilter",
            "name": "hiddenHttpMethodFilter",
            "servletNameMappings": [],
            "urlPatternMappings": [
                "/*"
            ]
        },
        {
            "className": "org.springframework.boot.web.servlet.filter.OrderedCharacterEncodingFilter",
            "name": "characterEncodingFilter",
            "servletNameMappings": [],
            "urlPatternMappings": [
                "/*"
            ]
        },
        {
            "className": "org.springframework.boot.actuate.trace.WebRequestTraceFilter",
            "name": "webRequestLoggingFilter",
            "servletNameMappings": [],
            "urlPatternMappings": [
                "/*"
            ]
        }
    ],
    "servlets": [
        {
            "className": "org.apache.catalina.servlets.DefaultServlet",
            "mappings": [],
            "name": "default"
        },
        {
            "className": "org.springframework.web.servlet.DispatcherServlet",
            "mappings": [
                "/"
            ],
            "name": "dispatcherServlet"
        }
    ]
}

And here's an example for a WebFlux application:

{
    "dispatcherHandlers": {
        "webHandler": [
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/auditevents],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/beans],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/autoconfig],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/configprops],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/env/{toMatch}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/env],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/health],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/status],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/info],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/loggers],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/loggers/{name}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$WriteOperationHandler.handle(org.springframework.web.server.ServerWebExchange,java.util.Map<java.lang.String, java.lang.String>)",
                "predicate": "{[/application/loggers/{name}],methods=[POST],consumes=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/threaddump],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/metrics],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/metrics/{requiredMetricName}],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/trace],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/mappings],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "public org.reactivestreams.Publisher<org.springframework.http.ResponseEntity<java.lang.Object>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping$ReadOperationHandler.handle(org.springframework.web.server.ServerWebExchange)",
                "predicate": "{[/application/heapdump],methods=[GET],produces=[application/octet-stream]}"
            },
            {
                "handler": "private java.util.Map<java.lang.String, java.util.Map<java.lang.String, org.springframework.boot.actuate.endpoint.web.Link>> org.springframework.boot.actuate.endpoint.web.reactive.WebFluxEndpointHandlerMapping.links(org.springframework.http.server.reactive.ServerHttpRequest)",
                "predicate": "{[/application],methods=[GET],produces=[application/vnd.spring-boot.actuator.v2+json || application/json]}"
            },
            {
                "handler": "sample.webflux.SampleWebFluxApplication$$Lambda$177/2063786038@49bd54f7",
                "predicate": "(POST && /echo)"
            },
            {
                "handler": "sample.webflux.SampleWebFluxApplication$$Lambda$179/1005093407@6b5f8707",
                "predicate": "(GET && /whatever)"
            },
            {
                "handler": "public java.lang.String sample.webflux.WelcomeController.welcome()",
                "predicate": "{[/],methods=[GET]}"
            },
            {
                "handler": "ResourceWebHandler [locations=[class path resource [META-INF/resources/webjars/]], resolvers=[org.springframework.web.reactive.resource.PathResourceResolver@3258b7d8]]",
                "predicate": "/webjars/**"
            },
            {
                "handler": "ResourceWebHandler [locations=[class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/]], resolvers=[org.springframework.web.reactive.resource.PathResourceResolver@6a38fa48]]",
                "predicate": "/**"
            }
        ]
    }
}

A few notes about the example responses:

• dispatcherServlets and dispatcherHandlers are as there may be more than one DispatcherServlet or DispatcherHandler bean in the application context.
• The keys in the dispatcherServlets and dispatcherHandlers maps are the names of the beans.
• The values in the dispatcherServlets and dispatcherHandlers maps are arrays of the known handlers. The order of the array reflects the order of the handlers in the dispatcher.
• The top-level keys (dispatcherServlets, dispatcherHandlers, servlets, servletFilters) are named such that they are unique even when a client might be dealing with a mixture of servlet and reactive web applications.
• It would be nice to be able to list WebFilters used by WebFlux but that doesn't appear to be possible (at the moment at least) without resorting to reflective hacks.
• The code that produced the above is in this branch of my fork.

[kaleev]

Mapping endpoint's output contains endpoints entries (e.g beans, health) when management port is equal to application port, and it doesn’t contain them when management port differs from application port.
It seems like a bug. So it should be possible to distinguish management request mappings and application request mappings in json output, since IDEA as well as STS need to build correct URLs for entries from the output in order to get an ability to navigate to them.
I suppose top-level 'context' keys would be enough.

[wilkinsona]

Thank you, @kaleev. Given that the change proposed here is going to be a breaking change to the JSON's structure, and fixing the problem you've described would also require a breaking change, doing both at the same time makes a lot of sense. I'll see what we can do.

[wilkinsona]

The problem with the mappings not being visible when there's a context hierarchy (as there is when the management port is set) is a specific case of the problem tracked by #5312.

[wilkinsona]

There's a problem with the proposed implementation when the management port has been configured. If a request to the mappings endpoint is made before the application's dispatcher servlet has handled any request, its handler mappings will be null as they are only initialized on first request by default. I've asked @rstoyanchev if there's anything that could be done in the Framework to remove this restriction.

[wilkinsona]

Nothing can be done in DispatcherServlet to address the problem described above however it's possible to write some container-specific logic to trigger initialisation of the DispatcherServlet when needed.

[wilkinsona]

The response structure has changed to align with the recent changes for better handling of context hierarchies. Here's an example of the updated structure:

{
    "contexts": {
        "application": {
            "mappings": {
                "dispatcherServlets": {
                    "dispatcherServlet": [
                        {
                            "handler": "ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/], ServletContext resource [/], class path resource []], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@282c6b8]]",
                            "predicate": "/**/favicon.ico"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<java.util.Map<java.lang.String, java.lang.Object>> org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.error(javax.servlet.http.HttpServletRequest)",
                            "predicate": "{[/error]}"
                        },
                        {
                            "handler": "public org.springframework.web.servlet.ModelAndView org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController.errorHtml(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse)",
                            "predicate": "{[/error],produces=[text/html]}"
                        },
                        {
                            "handler": "org.springframework.http.HttpEntity<org.springframework.data.rest.webmvc.RootResourceInformation> org.springframework.data.rest.webmvc.alps.AlpsController.descriptor(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/profile/{repository}],methods=[GET],produces=[application/alps+json || */*]}"
                        },
                        {
                            "handler": "org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.alps.AlpsController.alpsOptions()",
                            "predicate": "{[/api/profile/{repository}],methods=[OPTIONS],produces=[application/alps+json]}"
                        },
                        {
                            "handler": "public org.springframework.http.HttpEntity<org.springframework.data.rest.webmvc.json.JsonSchema> org.springframework.data.rest.webmvc.RepositorySchemaController.schema(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/profile/{repository}],methods=[GET],produces=[application/schema+json]}"
                        },
                        {
                            "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.ProfileController.profileOptions()",
                            "predicate": "{[/api/profile],methods=[OPTIONS]}"
                        },
                        {
                            "handler": "org.springframework.http.HttpEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.ProfileController.listAllFormsOfMetadata()",
                            "predicate": "{[/api/profile],methods=[GET]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.followPropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,java.lang.String,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws java.lang.Exception",
                            "predicate": "{[/api/{repository}/{id}/{property}/{propertyId}],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.followPropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws java.lang.Exception",
                            "predicate": "{[/api/{repository}/{id}/{property}],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<? extends org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.deletePropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String) throws java.lang.Exception",
                            "predicate": "{[/api/{repository}/{id}/{property}],methods=[DELETE],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.followPropertyReferenceCompact(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws java.lang.Exception",
                            "predicate": "{[/api/{repository}/{id}/{property}],methods=[GET],produces=[application/x-spring-data-compact+json || text/uri-list]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<? extends org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.createPropertyReference(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.http.HttpMethod,org.springframework.hateoas.Resources<java.lang.Object>,java.io.Serializable,java.lang.String) throws java.lang.Exception",
                            "predicate": "{[/api/{repository}/{id}/{property}],methods=[PATCH || PUT || POST],consumes=[application/json || application/x-spring-data-compact+json || text/uri-list],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryPropertyReferenceController.deletePropertyReferenceId(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,java.lang.String,java.lang.String) throws java.lang.Exception",
                            "predicate": "{[/api/{repository}/{id}/{property}/{propertyId}],methods=[DELETE],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.RepositoryController.optionsForRepositories()",
                            "predicate": "{[/api/ || /api],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryController.headForRepositories()",
                            "predicate": "{[/api/ || /api],methods=[HEAD],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.HttpEntity<org.springframework.data.rest.webmvc.RepositoryLinksResource> org.springframework.data.rest.webmvc.RepositoryController.listRepositories()",
                            "predicate": "{[/api/ || /api],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.optionsForCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/{repository}],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.headCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.support.DefaultedPageable) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}],methods=[HEAD],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.hateoas.Resources<?> org.springframework.data.rest.webmvc.RepositoryEntityController.getCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws org.springframework.data.rest.webmvc.ResourceNotFoundException,org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.hateoas.Resources<?> org.springframework.data.rest.webmvc.RepositoryEntityController.getCollectionResourceCompact(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws org.springframework.data.rest.webmvc.ResourceNotFoundException,org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}],methods=[GET],produces=[application/x-spring-data-compact+json || text/uri-list]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryEntityController.postCollectionResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.PersistentEntityResource,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,java.lang.String) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}],methods=[POST],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.optionsForItemResource(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/{repository}/{id}],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.headForItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}/{id}],methods=[HEAD],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.Resource<?>> org.springframework.data.rest.webmvc.RepositoryEntityController.getItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.http.HttpHeaders) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}/{id}],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<? extends org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryEntityController.putItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.PersistentEntityResource,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.data.rest.webmvc.support.ETag,java.lang.String) throws org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}/{id}],methods=[PUT],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<org.springframework.hateoas.ResourceSupport> org.springframework.data.rest.webmvc.RepositoryEntityController.patchItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.data.rest.webmvc.PersistentEntityResource,java.io.Serializable,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.data.rest.webmvc.support.ETag,java.lang.String) throws org.springframework.web.HttpRequestMethodNotSupportedException,org.springframework.data.rest.webmvc.ResourceNotFoundException",
                            "predicate": "{[/api/{repository}/{id}],methods=[PATCH],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositoryEntityController.deleteItemResource(org.springframework.data.rest.webmvc.RootResourceInformation,java.io.Serializable,org.springframework.data.rest.webmvc.support.ETag) throws org.springframework.data.rest.webmvc.ResourceNotFoundException,org.springframework.web.HttpRequestMethodNotSupportedException",
                            "predicate": "{[/api/{repository}/{id}],methods=[DELETE],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.data.rest.webmvc.RepositorySearchesResource org.springframework.data.rest.webmvc.RepositorySearchController.listSearches(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/{repository}/search],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.RepositorySearchController.optionsForSearches(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/{repository}/search],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.HttpEntity<?> org.springframework.data.rest.webmvc.RepositorySearchController.headForSearches(org.springframework.data.rest.webmvc.RootResourceInformation)",
                            "predicate": "{[/api/{repository}/search],methods=[HEAD],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<?> org.springframework.data.rest.webmvc.RepositorySearchController.executeSearch(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.util.MultiValueMap<java.lang.String, java.lang.Object>,java.lang.String,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler,org.springframework.http.HttpHeaders)",
                            "predicate": "{[/api/{repository}/search/{search}],methods=[GET],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.hateoas.ResourceSupport org.springframework.data.rest.webmvc.RepositorySearchController.executeSearchCompact(org.springframework.data.rest.webmvc.RootResourceInformation,org.springframework.http.HttpHeaders,org.springframework.util.MultiValueMap<java.lang.String, java.lang.Object>,java.lang.String,java.lang.String,org.springframework.data.rest.webmvc.support.DefaultedPageable,org.springframework.data.domain.Sort,org.springframework.data.rest.webmvc.PersistentEntityResourceAssembler)",
                            "predicate": "{[/api/{repository}/search/{search}],methods=[GET],produces=[application/x-spring-data-compact+json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<java.lang.Object> org.springframework.data.rest.webmvc.RepositorySearchController.optionsForSearch(org.springframework.data.rest.webmvc.RootResourceInformation,java.lang.String)",
                            "predicate": "{[/api/{repository}/search/{search}],methods=[OPTIONS],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "public org.springframework.http.ResponseEntity<java.lang.Object> org.springframework.data.rest.webmvc.RepositorySearchController.headForSearch(org.springframework.data.rest.webmvc.RootResourceInformation,java.lang.String)",
                            "predicate": "{[/api/{repository}/search/{search}],methods=[HEAD],produces=[application/hal+json || application/json]}"
                        },
                        {
                            "handler": "ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/webjars/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@72f56ddf]]",
                            "predicate": "/webjars/**"
                        },
                        {
                            "handler": "ResourceHttpRequestHandler [locations=[class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/], ServletContext resource [/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver@6656c23f]]",
                            "predicate": "/**"
                        }
                    ]
                },
                "servletFilters": [
                    {
                        "className": "org.springframework.boot.web.servlet.filter.OrderedRequestContextFilter",
                        "name": "requestContextFilter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    },
                    {
                        "className": "org.apache.tomcat.websocket.server.WsFilter",
                        "name": "Tomcat WebSocket (JSR356) Filter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    },
                    {
                        "className": "org.springframework.boot.web.servlet.filter.OrderedHttpPutFormContentFilter",
                        "name": "httpPutFormContentFilter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    },
                    {
                        "className": "org.springframework.boot.web.servlet.filter.OrderedHiddenHttpMethodFilter",
                        "name": "hiddenHttpMethodFilter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    },
                    {
                        "className": "org.springframework.boot.web.servlet.filter.OrderedCharacterEncodingFilter",
                        "name": "characterEncodingFilter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    },
                    {
                        "className": "org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter",
                        "name": "webMetricsFilter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    },
                    {
                        "className": "org.springframework.boot.actuate.trace.WebRequestTraceFilter",
                        "name": "webRequestLoggingFilter",
                        "servletNameMappings": [],
                        "urlPatternMappings": [
                            "/*"
                        ]
                    }
                ],
                "servlets": [
                    {
                        "className": "org.apache.catalina.servlets.DefaultServlet",
                        "mappings": [],
                        "name": "default"
                    },
                    {
                        "className": "org.springframework.web.servlet.DispatcherServlet",
                        "mappings": [
                            "/"
                        ],
                        "name": "dispatcherServlet"
                    }
                ]
            },
            "parentId": null
        }
    }
}

contexts is a new top-level entry. This map contains an entry for each application context, keyed by id, that's known to the endpoint. Each entry for a specific context has two keys: parentId and mappings. parentId is the id of the parent context, if any. mappings is a map of the context's mappings with entries that use the same 4 possible keys as described above (dispatcherServlets, dispatcherHandlers, servlets, servletFilters).

[wilkinsona]

The code would benefit from being in a mappings-specific package rather than the more general-purpose actuate.web package that it's currently in.