tomcat-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Tommy Pham <tommy...@gmail.com>
Subject Re: TC 9.0.21: ContextListener + Servlet app
Date Thu, 20 Jun 2019 09:32:56 GMT
Hi Chris,

On Mon, Jun 17, 2019 at 2:11 PM Christopher Schultz <
chris@christopherschultz.net> wrote:

> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA256
>
> Tommy,
> > Tommy,
> >
> > On 6/15/19 21:51, Tommy Pham wrote:
> >>>> Hi Mark,
> >>>>
> >>>> After some research and thought about internal application
> >>>> flow, I think the 'cleanest' is have TC's default servlet
> >>>> handle the *.html requests and use the assigned filter to
> >>>> restrict the access as desired.  Is there a better approach?
> >>>> On that plan, I have this mapping for TC's default servlet
> >>>> and init:
> >>>>
> >>>> Filter AppFilterAccessLog's servlet mapping: Servlet name:
> >>>> default , registered class:
> >>>> org.apache.catalina.servlets.DefaultServlet. Servlet
> >>>> default's mapping: /img/* /css/* /WEB-INF/*
> >
> > Uh... you sure you want that? What is stopping a client from
> > requesting /WEB-INF/web.xml?
> >
> >>>> /js/* Servlet default's init parameters: listings: false
> >>>> debug: 0
> >>>>
> >>>> If I use *.html instead of /WEB-INF/*, it goes into infinite
> >>>> loop redirecting / forwarding until exception is thrown (I
> >>>> think that root cause is servlets' startup ordering).  Below
> >>>> are what my access log filter see for HttpServletRequest:
> >>>>
> >>>> Attributes:
> >>>> javax.servlet.forward.request_uri=/erm-0.0.1-SNAPSHOT/
> >>>> javax.servlet.forward.context_path=/erm-0.0.1-SNAPSHOT
> >>>> javax.servlet.forward.servlet_path=
> >>>> javax.servlet.forward.path_info=/
> >>>>
> >>>> javax.servlet.forward.mapping=org.apache.catalina.core.ApplicationM
> app
> >
> >>>>
> ing$MappingImpl@7fc1f887
> >>>>
> >>>>
> > org.apache.logging.log4j.web.Log4jServletFilter.FILTERED=true
> >>>> Class: org.apache.catalina.core.ApplicationHttpRequest
> >>>> DispatcherType: FORWARD [javax.servlet.DispatcherType]
> >>>> HttpServletMapping: Class:
> >>>> org.apache.catalina.core.ApplicationMapping$MappingImpl
> >>>> MappingMatch: PATH MatchValue: setup/step_0.html Pattern:
> >>>> /WEB-INF/* ServletName: default
> >>>>
> >>>> Below is from the actual filter assigned to TC's default
> >>>> servlet intended to restrict access:
> >>>>
> >>>> ContextPath: /erm-0.0.1-SNAPSHOT DispatcherType: FORWARD
> >>>> PathInfo: /setup/step_0.html PathTranslated:
> >>>> D:\apache-tomcat-9.0.21\webapps\erm-0.0.1-SNAPSHOT\setup\step_0.htm
> l
> >>>>
> >>>>
> >
> >>>>
> Method: GET
> >>>> RequestURI: /erm-0.0.1-SNAPSHOT/WEB-INF/setup/step_0.html
> >>>> RequestURL:
> >>>> http://localhost:8080/erm-0.0.1-SNAPSHOT/WEB-INF/setup/step_0.html
> >>>>
> >>>>
> ServletPath: /WEB-INF ServletContext.ServletContextName: erm
> >>>> response: org.apache.catalina.connector.ResponseFacade
> >>>>
> >>>> I think everything seems correct except the PathTranslated.
> >>>> It should be:
> >>>>
> >>>> D:\apache-tomcat-9.0.21\webapps\erm-0.0.1-SNAPSHOT\WEB-INF\setup\st
> ep_
> >
> >>>>
> 0.html
> >>>>
> >>>> where the file is.  I'm unable to find out why it's wrong
> >>>> after a couple hours of searching since the the browser shows
> >>>> an empty page...  The string "/WEB-INF/setup/step_0.html" was
> >>>> passed to request.getRequestDispatcher(). According to the
> >>>> doc [1], " If the path begins with a "/" it is interpreted as
> >>>> relative to the current context root." everything is as it
> >>>> should be right, other than PathTranslated?  Or did I
> >>>> misunderstood the usage of getRequestDispatcher().forward()?
> >>>> Currently, I have 4 filters in place and all are in passive
> >>>> monitoring mode.  None of them have the code logic to perform
> >>>> their intended functions.  3 filters mapped to URL /* and one
> >>>> assigned to TC's default servlet.  I'll work out their
> >>>> filtering order before the intended functions are
> >>>> implemented.
> >
> > Filters are applied in a predictable order. I highly recommend
> > reading the servlet specification to see how these things are
> > defined to work. It's quite readable.
> >
> > Why not allow Tomcat to serve everything in the web application
> > (other than /WEB-INF/* and /META-INF/*) as usual? What is it that
> > you need to put into there that you can't hide in some other way?
> >
> > It sounds like you are unnecessarily complicating your life.
> >
> > -chris
> >
> >
> >> I was using "/WEB-INF/*" as a test of the scaffolding for my
> >> application since previously "*.html" ended up infinite loop
> >> which, eventually, it threw an exception.  Now that I've got
> >> "*.html" working, I'm still getting a blank page.  The HTML files
> >> are only served as UI for the initial setup of the application.
> >> There won't be any static files other than JS, CSS, and images
> >> when the application is fully configured by administrator.  Here
> >> are the servlets configuration:
> >
> >> Servlet name: default , registered class:
> >> org.apache.catalina.servlets.DefaultServlet. Servlet default's
> >> mapping: /img/* /css/* /js/* *.html Servlet default's init
> >> parameters: listings: false debug: 0 Servlet name: AppServlet ,
> >> registered class: com.sointe.web.AppServlet. Servlet AppServlet's
> >> mapping: / Servlet AppServlet's init parameters: Servlet name:
> >> jsp , registered class: org.apache.jasper.servlet.JspServlet.
> >> Servlet jsp's mapping: *.jspx *.jsp Servlet jsp's init
> >> parameters: fork: false xpoweredBy: false
> >
> >> And HttpServletRequest's info:
> >
> >> Attributes:
> >> javax.servlet.forward.request_uri=/erm-0.0.1-SNAPSHOT/
> >> javax.servlet.forward.context_path=/erm-0.0.1-SNAPSHOT
> >> javax.servlet.forward.servlet_path=/
> >
> >> javax.servlet.forward.mapping=org.apache.catalina.core.ApplicationMap
> ping$MappingImpl@5e9215c0
> >>
> >>
> org.apache.logging.log4j.web.Log4jServletFilter.FILTERED=true
> >> DispatcherType: FORWARD [javax.servlet.DispatcherType]
> >> HttpServletMapping: Class:
> >> org.apache.catalina.core.ApplicationMapping$MappingImpl
> >> MappingMatch: EXTENSION MatchValue: WEB-INF/setup/step_0 Pattern:
> >> *.html ServletName: default
> >
> >> and the actual filter assigned to TC's default servlet to
> >> restrict access:
> >
> >> AppFilterStaticFiles.doFilter:52 - Class:
> >> org.apache.catalina.core.ApplicationHttpRequest
> >> AppFilterStaticFiles.doFilter:53 - ServletContext Class:
> >> org.apache.catalina.core.ApplicationContextFacade
> >> AppFilterStaticFiles.doFilter:54 - ContextPath:
> >> /erm-0.0.1-SNAPSHOT AppFilterStaticFiles.doFilter:55 -
> >> DispatcherType: FORWARD AppFilterStaticFiles.doFilter:56 -
> >> Method: GET AppFilterStaticFiles.doFilter:57 - PathInfo: null
> >> AppFilterStaticFiles.doFilter:58 - PathTranslated: null
> >
> >> AppFilterStaticFiles.doFilter:59 -
> >> getServletContext().getRealPath() of ServletPath:
> >> D:\apache-tomcat-9.0.21\webapps\erm-0.0.1-SNAPSHOT\WEB-INF\setup\step
> _0.html
> >
> >>  AppFilterStaticFiles.doFilter:60 - RequestURI:
> >> /erm-0.0.1-SNAPSHOT/WEB-INF/setup/step_0.html
> >> AppFilterStaticFiles.doFilter:61 - RequestURL:
> >> http://localhost:8080/erm-0.0.1-SNAPSHOT/WEB-INF/setup/step_0.html
> >>
> >>
> AppFilterStaticFiles.doFilter:62 - ServletPath: /WEB-INF/setup/step_0.ht
> ml
> >> AppFilterStaticFiles.doFilter:63 -
> >> ServletContext.ServletContextName: erm
> >> AppFilterStaticFiles.doFilter:67 - response:
> >> org.apache.catalina.connector.ResponseFacade
> >
> >> In looking at the code for ApplicationHttpRequest [1] for the
> >> getPathTranlated()
> >
> >> @Override public String getPathTranslated() { if (getPathInfo()
> >> == null || getServletContext() == null) { return null; } return
> >> getServletContext().getRealPath(getPathInfo()); }
> >
> >> and for the getRequestDispatcher()
> >
> >> if (pathInfo == null) { requestPath = servletPath; } else {
> >> requestPath = servletPath + pathInfo; }
> >
> >> Perhaps the getPathTranslated() could be ?
> >
> >> if ( getServletContext() != null) { if (getServletPath() != null)
> >> { if (getPathInfo() != null) {
> >
> >> return getServletContext().getRealPath(getServletPath() +
> >> getPathInfo()); } return
> >> getServletContext().getRealPath(getServletPath()); } } return
> >> null;
> >
> >> I think that would also fix the translated path I saw earlier
> >> which resulted in a blank page for the browser.
>
> I really don't understand why you need anything other than the plain,
> vanilla, default configuration, here. If you can explain that, it will
> go a long way towards anyone being able to help you.
>
> - -chris
>

I have some theories that I'm trying to do a PoC for.  I was debating
between have a class to generate the HTML content for setup but it would
make the page design more complicated and additional development time for
something that's mostly like used once.  That's why I settled on static.
As for default configuration, I plan on having only one listener and one
servlet for all requests of dynamic content and delegate accordingly as per
my theories.  Hence, I needed to change slightly in configuration.

Thanks,
Tommy


> -----BEGIN PGP SIGNATURE-----
> Comment: Using GnuPG with Thunderbird - https://www.enigmail.net/
>
> iQIzBAEBCAAdFiEEMmKgYcQvxMe7tcJcHPApP6U8pFgFAl0IAgQACgkQHPApP6U8
> pFgdShAAiKarcsflVVFk15fxDIJveFclsnxhtLBJ5TJcbRkBwMCtPUgfTheOSTON
> MEu9LN6F0/gXJWrXozPjUgn7g09LqCmMz9IbF6TQLBhP0zEO+oQl7mSOglGu+ePo
> 7uKfsp6zJFLQfrMo6E+bifCqqJiuV4OOtmdUnpAXM6LXcs7pB2Ge9kqObzuIY2Kv
> J9Pkgiln0ikPIQb2zEl3kDrPTHCaE8qB3C8wiLVoGadsQKDcSQYDrl78SDV2vWzX
> XLbDbxqgB/zbKRaLBKoSxE3VbiMuvmmAwPumbAD/bonqAki1xWTfcSXz8V7PySPl
> RbqGFkzyw9J4M+DNdoanzNRUoxsSeeaLNOC/c6wI21+Nb6g2NCdzMZH8t2GLSYSI
> EyoA9/7xsP2U4kXWd/UDJMfi+NNAMyn1o/wd3GCliwgRYU98cmApkGSqdcFonbwc
> dIx8HUYrOSUZOYf+hA3+jEznYcflUlMX92bXkMwxEFh6RGQq70z9WT93zqG/r06x
> MnhQ9/qvngFErknLSLqi/iP5uXG+KVynzThZT1NmE6PWQJNHqxWi0l8VFdK8bUdt
> vZUd8OHN5eWDSeoySuDzPTcalLmZoK3HvC1DNqUse+L8YSKROy6r0zkyMbMwf2w6
> vasQT+wQKUBkD9KnnL2cPumj7be16pygT/S5XWs6EY0N0qNJ1dI=
> =HSjP
> -----END PGP SIGNATURE-----
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: users-unsubscribe@tomcat.apache.org
> For additional commands, e-mail: users-help@tomcat.apache.org
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message