Filter mapping in Spring MVC is not working on some URL

I am using HTML Filter to delete white spaces from out put of my jsp pages and servlets. I am learning JSP development with Spring MVC. So I am using filter mapping and error page with web.xml file and my web.xml codes are

<servlet>
    <servlet-name>mvc-dispatcher</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <load-on-startup>1</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>mvc-dispatcher</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<error-page>
    <error-code>404</error-code>
    <location>/error404</location>
</error-page>

<filter>
    <filter-name>whitespaceFilter</filter-name>
    <filter-class>test.web.htmlminify.HTMLMinifyFilter</filter-class>
</filter>
<filter-mapping>
    <filter-name>whitespaceFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

And I have three controllers with no methods but only returning pages which are

HomeController, TestController, Error404Controller

which has homePage(), testPage() and errorPage() method which are returning following ,

return "home";
return "test";
return "error";

And I do have one jsp file outside of WEB-INF folder named abc.jsp file.

So situation is that when I access localhost, localhost/abc.jsp, localhost/testpage and localhost/error404

the filter mapping is working, as when I see source code of html webpage in browser, there is not white space in it but when i try to access localhost/ashhjb or localhost/kjdhvid/sdvfdjiu anything like that, filter mapping is not working. It means I am seeing white spaces in html pages when servlet is calling 'error' page instead of direct error controller method in browser. localhost/error404 is direct call to error page servlet. So can anyone help me and suggest me what should I do?

Thanx for helping in advance.