[FIXED] Understanding of url-patterns in web.xml

Issue

I was really confused by this parts of web.xml:

<filter>
    <filter-name>filter</filter-name>
    <filter-class>com.labwork.filter.Filter</filter-class>
</filter>

<filter-mapping>
    <filter-name>filter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

This is the real problem. For example, I have several Servlets and static html pages. All request to them pass through filter. May be, i want to forward to servlet/html page from filter. How can i do this, if all request will be forward to filter? Or, may be, i don't understand principles.

Solution

Based on our conversation in the comment section, you want to filter every request with an exception of a few pages.

Let's say you want to exempt the login.html from filtering, what you could do is get the request URI and check if that string contains login.html like this:

public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {                
    String path = ((HttpServletRequest) request).getRequestURI();
    if (path.contains("login.html")) //login page                                                
        chain.doFilter(request, response); //proceed to the page
    } else {            
        //conditions here
    }
}

I must state though that this is not the standard practice. If you're doing this then you should review your design choices.

Answered By - lxcky
Answer Checked By - Pedro (JavaFixing Volunteer)