spring boot 1.4 jsp page not evaluated Forward InternalViewResolver - spring

Question

After 2 days of investigation, and looking a lot of answers about my issue, I cannot solve it.
I am not expert of spring framework.
Entry point :
I have generate a jhipster project a year ago. I want to embed jsp pages in my project.
I'm using spring boot 1.4 in a maven project
I have include dependency following :
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
I have created a new servlet in WebConfigurer class which implements ServletContextInitializer.onStartup and created a file named servletJsp-servlet.xml in a WEB-INF resources folder.
The xml instanciate InternalViewResolver with prefix /mesPages/ and suffix=.jsp
I created also a controller :
#Controller
public class TestJspController {
#RequestMapping(value = "/jsp/bbb")
public ModelAndView serveLog4jAdmin() {
return new ModelAndView("log4jAdmin");
}
}
I stick here : (see log below)
The logs say that :
Controller is well called
It returns well the ModelAndView
Launch Forward to resource [/mesPagesJsps/log4jAdmin.jsp] from InternalResourceView 'log4jAdmin'
But after that, instead of getting it and rendering it, no stacktrace and try to resolve jsp page with another servlet : dispatcherServlet (I believe this is the defaut spring autoconfigured and created) spring servlet.
The dispatcherServlet is successfull in getting it because I have put my folder mesPages (which contains my jsps) every where in the project (META-INF, WEB-INF, root folders) of resources and webapp
Finally, the jsp page is not evaluated, and broswer give me to download it as "application/octet-stream".
Previously before putting jsp on all these folders, I uses to have the same controller behaviour but ending with 404 error (blank page).
I really don't understand why app behave like this.
I have another spring (not boot) webapp which works well.
I tried to debug, but to complex for me ... When debugging I was just detect that the requestDispatcher cannot dispatch Forward because there is no Handler with type FORWARD in some 'next' variables.
I think this is the cause ...
If someone has some anwser, I would be very happy
I can give any other information that is required.
The concerned part of log :
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : DispatcherServlet with name 'servletJSP' processing GET request for [/jsps/jsp/bbb]
[ XNIO-3 task-2] s.w.s.m.m.a.RequestMappingHandlerMapping : Looking up handler method for path /jsp/bbb
[ XNIO-3 task-2] s.w.s.m.m.a.RequestMappingHandlerMapping : Returning handler method [public org.springframework.web.servlet.ModelAndView fr.softeam.testify.web.rest.jsp.TestJspController.serveLog4jAdmin()]
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : Last-Modified value for [/jsps/jsp/bbb] is: -1
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : Rendering view [org.springframework.web.servlet.view.JstlView: name 'log4jAdmin'; URL [/mesPagesJsps/log4jAdmin.jsp]] in DispatcherServlet with name 'servletJSP'
[ XNIO-3 task-2] o.s.web.servlet.view.JstlView : Forwarding to resource [/mesPagesJsps/log4jAdmin.jsp] in InternalResourceView 'log4jAdmin'
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : DispatcherServlet with name 'dispatcherServlet' processing GET request for [/mesPagesJsps/log4jAdmin.jsp]
[ XNIO-3 task-2] s.w.s.m.m.a.RequestMappingHandlerMapping : Looking up handler method for path /mesPagesJsps/log4jAdmin.jsp
[ XNIO-3 task-2] s.w.s.m.m.a.RequestMappingHandlerMapping : Did not find handler method for [/mesPagesJsps/log4jAdmin.jsp]
[ XNIO-3 task-2] o.s.w.s.handler.SimpleUrlHandlerMapping : Matching patterns for request [/mesPagesJsps/log4jAdmin.jsp] are [/**]
[ XNIO-3 task-2] o.s.w.s.handler.SimpleUrlHandlerMapping : URI Template variables for request [/mesPagesJsps/log4jAdmin.jsp] are {}
[ XNIO-3 task-2] o.s.w.s.handler.SimpleUrlHandlerMapping : Mapping [/mesPagesJsps/log4jAdmin.jsp] to HandlerExecutionChain with handler [ResourceHttpRequestHandler [locations=[ServletContext resource [/], class path resource [META-INF/resources/], class path resource [resources/], class path resource [static/], class path resource [public/]], resolvers=[org.springframework.web.servlet.resource.PathResourceResolver#1774cad]]] and 1 interceptor
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : Last-Modified value for [/mesPagesJsps/log4jAdmin.jsp] is: -1
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : Null ModelAndView returned to DispatcherServlet with name 'dispatcherServlet': assuming HandlerAdapter completed request handling
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : Successfully completed request
[ XNIO-3 task-2] o.s.web.servlet.DispatcherServlet : Successfully completed request

Answer 1

Because I wanted a new path for all jsps (I know we can do that in controller too), and I feared that keep the same servlet for serving both angular frontend and jsp.
Because jhipster generate a lot of class which parameterize (HttpSecurity, ), I though that create a new servlet (without any custom parameters) could be more simple and avoid problems.
DispatcherServlet.render()
--> resolveViewName() qui retourne une JstlView
--> JstlView.render()
--> renderMergedOutputModel()
dispatcherPath = prepareForRendering(request, response); // dispatcherPath = /mesPagesJsps/log4jAdmin.jsp
RequestDispatcher rd = getRequestDispatcher() // rd.path=/mesPagesJsps/log4jAdmin.jsp and rd.servletChain=another DispatcherServlet !!! why ??? named dispatcherServlet, which is not my jsp servlet
--> rd.forward()
--> forwardImpl()
--> response.resetBuffer()
newServletPath = newRequestUri = /mesPagesJsps/log4jAdmin.jsp
pathMatch.servletChain still contains wrond servlet : dispatcherServlet instead of jspServlet
--> servletContext.getDeployment().getServletDispatcher().dispatchToPath(requestImpl.getExchange(), pathMatch, DispatcherType.FORWARD);
--> servletInitialDispatcher.dispatchToPath()
servletRequestContext.servletChain correspond to my servletJSP
--> dispatchRequest( pathInfo = /mesPagesJsps/log4jAdmin.jsp, dispatcherType=FORWARD, servletChain is not my jsp servletJSP but dispatcherServlet )
Exchange is : HttpServerExchange{ GET /mesPagesJsps/log4jAdmin.jsp request {Accept=[text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8], Accept-Language=[fr,fr-FR;q=0.8,en-US;q=0.5,en;q=0.3], Cache-Control=[max-age=0], Accept-Encoding=[gzip, deflate], User-Agent=[Mozilla/5.0 (Windows NT 6.1; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0], Connection=[keep-alive], Cookie=[CSRF-TOKEN=f6843de6-766d-4259-8a84-242c020420bc; JSESSIONID=VrVa7HNkUmzv_JM_cAhwyrfGWGCcrjZSltoQh2EJ], Upgrade-Insecure-Requests=[1], Host=[localhost:8080]} response {X-Application-Context=[testify_jhi:swagger,dev:8080], Content-Language=[fr-]}}
--> servletInitialHandler.dispatchRequest()
setCurrentServlet( WITH SERVLET dispatcherServlet and NOT servletJSP )
--> next.handleRequest(exchange) : next is here a SessionRestoringHandler
--> next.handleRequest(exchange) : next is here PredicateHandler. This called because a sessionId has been found ...
--> predicate.resolve() with a predicate of type REQUEST (I think this bad) --> which return falseHandler
--> next.handleRequest() --> with again a predicate of type REQUEST --> which return falseHandler
--> next.handleRequest() --> with a ServletDispatchingHandler whose ServletChain is the wrong servlet : dispatcherServlet instead of servletJSP
the dispatcher type is still FORWARD here but its to late because I thing the wrong servlet process the request

Answer 2

Because I wanted a new path for all jsps (I know we can do that in controller too), and I feared that keep the same servlet for serving both angular frontend and jsp.
Because jhipster generate a lot of class which parameterize (HttpSecurity, ), I though that create a new servlet (without any custom parameters) could be more simple and avoid problems.
For example there is HttpSecurity, and this :
public void customize(ConfigurableEmbeddedServletContainer container) {
MimeMappings mappings = new MimeMappings(MimeMappings.DEFAULT);
// IE issue, see https://github.com/jhipster/generator-jhipster/pull/711
mappings.add("html", "text/html;charset=utf-8");
// CloudFoundry issue, see https://github.com/cloudfoundry/gorouter/issues/64
mappings.add("json", "text/html;charset=utf-8");
//mappings.add("jsp", "text/html;charset=utf-8"); // si je fais ça, en combinaisais avec le addResourcesHandler(), alors la page jsp est affichée dans le navigateur
container.setMimeMappings(mappings);
// When running in an IDE or with ./mvnw spring-boot:run, set location of the static web assets.
setLocationForStaticAssets(container);
}

Answer 3

I finally found and solve the problem (solution bellow), it seems to have link with some undertow elements, which is not configured by defaut to initialize japser. JasperInitializer was never initialized.
If someone want explain me he is welcome :)
You must add this code in a configuration class.
#Bean
public TomcatContextCustomizer tomcatContextCustomizer() {
return new TomcatContextCustomizer() {
#Override
public void customize(Context context) {
context.addServletContainerInitializer(new JasperInitializer(), null);
}
};
}
#Bean
public TomcatEmbeddedServletContainerFactory tomcatContainerFactory() {
TomcatEmbeddedServletContainerFactory factory = new TomcatEmbeddedServletContainerFactory();
factory.setTomcatContextCustomizers(Arrays.asList(new TomcatContextCustomizer[] { tomcatContextCustomizer() }));
return factory;
}
Another question : I have no xml files in my spring boot application, except one :
Is it possible to replace my servlet web application context definition that I build with my WEB-INF/servletJSP-servlet.xml by java/annotation definition ?