重定向到配置的错误页面

Question

I have a servlet that handles requests that match a pattern (*.sth). Now I want to throw a 404, if an URL was called, that matches the pattern but was not supposed to be called. I do this by setting the status on HttpServletResponse. In the web.xml is a custom error page for 404s configured. This error page is opened, if the tomcat itself throws a 404, but not with my servlet. Of course I can call the page directly, but I'm interested in a more generic way because the servlet is used in other web apps, too. Is there a way to get the configured error pages to be able to redirect to them or tell the web container to use them?

web.xml snippet:

<servlet>
    <display-name>Controller</display-name>
    <servlet-name>Controller</servlet-name>
    <servlet-class>com.example.Controller</servlet-class>
</servlet>

<servlet-mapping>
    <servlet-name>Controller</servlet-name>
    <url-pattern >*.do</url-pattern>
</servlet-mapping>

<error-page>
    <error-code>404</error-code>
    <location>
        /error.do
    </location>
</error-page>

setting status:

response.setStatus(HttpServletResponse.SC_NOT_FOUND);

Answer 1

i think

<error-page>
    <error-code>404</error-code>
    <location>/error.do</location>
</error-page>

should be in web.xml inside conf folder of tomcat.

Answer 2

'home' gave the right clue. Using sendError() instead of setStatus() does what I want. Thanks!