welcome-file in web.xml with spring not working?

Question

I have setup my spring-mvc servlet to match *.page requests. I have setup the welcome-file-list in web.xml to be index.page

This works when I go to the root of my webserver:

http://me.com does get redirected to http://me.com/index.page correctly.

However, it doesn't redirect when I use subdirectoris:

http://me.com/dashboard does not get redirected to http://me.com/dashboard/index.page

Is there any way to get this mapping working?

My web.xml file (extract):

<welcome-file-list>
    <welcome-file>index.page</welcome-file>
</welcome-file-list>

<servlet-mapping>
    <servlet-name>spring-mvc</servlet-name>
    <url-pattern>*.page</url-pattern>
</servlet-mapping>

My webdefault.xml (from jetty):

    <init-param>
        <param-name>dirAllowed</param-name>
        <param-value>false</param-value>
    </init-param>
    <init-param>
        <param-name>welcomeServlets</param-name>
        <param-value>true</param-value>
    </init-param>
    <init-param>
        <param-name>redirectWelcome</param-name>
        <param-value>false</param-value>
    </init-param>

Solution 1

It will work only for real, physical directories, not won't work for arbitrary servlet mappings simulating directory structure.

Spring MVC allows very complex URL mappings, so you'd better handle this scenario with @RequestMapping

Solution 2

The <welcome-file> should represent a physically existing file in an arbitrary folder which you would like to serve whenever the enduser requests a folder (such as the root /, but it can also be any other folder such as /foo/). You only need to understand that the servletcontainer will test its physical existence before performing a forward, if it does not exist then a HTTP 404 page not found error will be returned.

In your particular case, you do not have a physical index.page file in your root folder. You have actually a index.jsp file in your root folder. The index.page is merely a virtual URL. So the servletcontainer won't be able to find the physical index.page file and hence error out with a 404.

You can workaround this by fooling the servletcontainer by placing a physically existing index.page file next to the index.jsp file in the same folder. That file can just be kept completely empty. The servletcontainer will find the file and then forward to index.page which will then invoke the controller servlet which in turn will actually serve the index.jsp as view. That'll work just fine.

Solution 3

To avoid forwarding welcome file itself, its better add a mapping for it.

  <servlet-mapping>
     <servlet-name>spring-mvc</servlet-name>
     <url-pattern>index.html</url-pattern>
  </servlet-mapping>

And in case of java configuration you can override two methods in class that extends WebMvcConfigurerAdapter

@Override
public void addViewControllers(ViewControllerRegistry registry) {
    registry.addViewController("/").setViewName("/index");
}

@Override
public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
    configurer.enable();
}

If you wanna serve index.html explicitly, turn it into a resource override a method in the same class as below:

@Override
public void addResourceHandlers(ResourceHandlerRegistry registry) {
    registry.addResourceHandler("/index.html").addResourceLocations("/WEB-INF/views/index.html");
}

Of course addResourceLocations must follows the folder choosen to hold your views.

See these samples

Comments

[John Farrelly]

Hi Bozho. Are you sure? The documentation docs.oracle.com/cd/E13222_01/wls/docs81/webapp/… makes it seem like directories should be supported.

[Bozho]

might be the way they implemented it in WebLogic. But Jetty are probably interpreting the standard differently. Try it in a completely new application, without spring, just to test

[John Farrelly]

It worked in a new spring application. However, the difference being that I had real files in real directories, instead of pointing to servlets. Perhaps that is the issue...

[John Farrelly]

Hi Ryan. That's what I'm doing at the moment, but unfortunately it only works at the root of the context, and not in subdirectories.

[John Farrelly]

Couldn't find a way to solve it, so I just had to append index.page to all my URLs. Tedious work!

[BalusC]

The welcome file is not only about the root of the context.

[John Farrelly]

Hi BalusC. There is a special parameter in webdefault.xml in Jetty called welcomeServlets. If you set it to true, then Jetty will look for a servlet that satisfies the welcome-file if a physical file does not exist. I have that set to true, and it worked for the root context, but does not work for subdirectories unfortunately.

[Kal]

Creating an empty file to trick the container is a bit of genius. Thanks!

[Koray Tugay]

You are a genius.