Question

What happens if I have two servlet mappings in web.xml that match a request? Does it choose most specific?

For example if I have the following xml and a request comes to …./something while it go to somethingservlet or everything_else servlet?

   <servlet-mapping>
      <servlet-name>something</servlet-name>
      <url-pattern>/something</url-pattern>
  </servlet-mapping>    

  <servlet-mapping>
    <servlet-name>everything_else</servlet-name>
    <url-pattern>/*</url-pattern>
  </servlet-mapping>

Answer 1

First succesful match will be used.

There are certain mapping rules follwed by servlet container. Read Servlet 2.5 specification chapter SRV.11:

The path used for mapping to a servlet is the request URL from the request
object minus the context path and the path parameters. The URL path mapping
rules below are used in order. The first successful match is used with no further
matches attempted:

1. The container will try to find an exact match of the path of the request to the path of the servlet. A successful match selects the
   servlet.
2. The container will recursively try to match the longest path-prefix. This is done
   by stepping down the path tree a directory at a time, using the ’/’ character as
   a path separator. The longest match determines the servlet selected.
3. If the last segment in the URL path contains an extension (e.g. .jsp), the servlet
   container will try to match a servlet that handles requests for the extension.
   An extension is defined as the part of the last segment after the last ’.’ character.
4. If neither of the previous three rules result in a servlet match, the container will
   attempt to serve content appropriate for the resource requested. If a “default”
   servlet is defined for the application, it will be used.