Spring MVC on WebSphere Liberty, 404s on all Spring URLs - eclipse

Question

Eclipse Oxygen with WebSphere Development Tools (WDT), Spring MVC 4.3.14, WebSphere Liberty Core 18.0.0.1 on Java 8. Liberty Features enabled (deliberately not latest) are:
<featureManager>
<feature>adminCenter-1.0</feature>
<feature>localConnector-1.0</feature>
<feature>jaxrs-1.1</feature>
<feature>concurrent-1.0</feature>
<feature>webProfile-6.0</feature>
<feature>jaxb-2.2</feature>
</featureManager>
JSPs on the context root are working fine, so that's correct. Also, ibm-web-ext.xml has <context-root uri="/webapp/gatewaymvm/" />
The Spring startup logging indicates that my #Controller classes are binding to the paths I expect:
10:31:24,102 DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:Looking for request mappings in application context: WebApplicationContext for namespace 'Spring MVC Dispatcher-servlet': startup date [Thu Apr 05 10:31:22 CDT 2018]; parent: Root WebApplicationContext
....
10:31:24,125 DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:1 request handler methods found on class mypackage.QueryTransactionController: {public mypackage.QueryTransResponse mypackage.QueryTransactionController.processRequest(mypackage.QueryTransRequest,javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws java.io.IOException={[/QueryTransaction],methods=[POST],consumes=[application/json || application/xml],produces=[application/json || application/xml]}}
10:31:24,125 INFO org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:Mapped "{[/QueryTransaction],methods=[POST],consumes=[application/json || application/xml],produces=[application/json || application/xml]}" onto public mypackage.QueryTransResponse mypackage.QueryTransactionController.processRequest(mypackage.QueryTransRequest,javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws java.io.IOException
...
10:31:24,130 DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:1 request handler methods found on class mypackage.TestPostJSONDocumentController: {public java.lang.String mypackage.TestPostDocumentController.execute(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws java.io.IOException={[/testPostJSONDoc],methods=[POST]}}
10:31:24,130 INFO org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:Mapped "{[/testPostJSONDoc],methods=[POST]}" onto public java.lang.String mypackage.TestPostDocumentController.execute(javax.servlet.http.HttpServletRequest,javax.servlet.http.HttpServletResponse) throws java.io.IOException
Yet, when I hit any of those URLs, they produce 404 responses and log entries like the following:
10:32:40,067 DEBUG org.springframework.web.servlet.DispatcherServlet:DispatcherServlet with name 'Spring MVC Dispatcher' processing POST request for [/webapp/gatewaymvm/testPostJSONDoc]
10:32:40,067 DEBUG org.springframework.webflow.mvc.servlet.FlowHandlerMapping:No flow mapping found for request with URI '/webapp/gatewaymvm/testPostJSONDoc'
10:32:40,068 DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:Looking up handler method for path testPostJSONDoc
10:32:40,075 DEBUG org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping:Did not find handler method for [testPostJSONDoc]
10:32:40,076 WARN org.springframework.web.servlet.PageNotFound:No mapping found for HTTP request with URI [/webapp/gatewaymvm/testPostJSONDoc] in DispatcherServlet with name 'Spring MVC Dispatcher'
This same application, when deployed to "Traditional" WAS, works as expected. I imagine there's something obvious I'm missing about Liberty, Liberty under Eclipse, or Spring MVC under Liberty.

Answer 1

At some point during my testing, where I had code that constructed a URL from the current request, I had seen /webapp/gatewaymvm//resource, with two slashes together.
So I tried removing the trailing slash from the places where I had a context root of /webapp/gatewaymvm/, and that resolved the issue. Either from server.xml if I have the WAR installed there directly, or from application.xml if I have the WAR installed in an EAR/Enterprise project.
Interesting that the JSPs worked with the trailing slash there, but the Spring paths did not.