Filter mapping url-pattern that excludes subdirectories

Question

Is there any way to make a filtermapping not include subdirectories?

For example.

I have .xhtml files in my context root, and I also have a subfolder named "test" with files with the same extension. Is there any may to map a filter to the files in context root and not to the files in the "test" directory?

Answer 1

The url-pattern is indeed restrictive in matching. It only allows exact, prefix or suffix matchnig. Not midst/overall/regex matching. So e.g. /*.xhtml what you intend to do ain't going to work.

If you want to exclude XHTML in the /test folder only, then your best is really a Filter listening on an url-pattern of *.xhtml which does basically the following job in doFilter() method:

// First cast ServletRequest to HttpServletRequest.
HttpServletRequest hsr = (HttpServletRequest) request;

// Check if requested resource is not in /test folder.
if (!hsr.getServletPath().startsWith("/test/")) {
    // Not in /test folder. Do your thing here.
}

The HttpServletRequest#getServletPath() basically returns the part of the request URI from the context path on.

You can if necessary configure the value /test as an <init-param> of the filter so that you can control the value from inside the web.xml instead of in the Filter's code.

Answer 2

The solution, basically you need your own Filter class and define excluding URLs as init-param for filter

package test;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

public class LoginValidationFilter implements Filter {

    private String loginPage = "";
    private List<String> excludedURLs;

    public void init(FilterConfig filterConfig) throws ServletException {
        this.loginPage = filterConfig.getInitParameter("loginPage");

        String[] excluded = filterConfig.getInitParameter("excludedURLs").split(";");
        excludedURLs = new ArrayList<String>();
        for (int i = 0; i < excluded.length; i++) {
            excludedURLs.add(excluded[i]);
        }
    }

    public void destroy() {
        this.loginPage = "";
    }

    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException,
            ServletException {

        HttpServletRequest httpRequest = request instanceof HttpServletRequest ? (HttpServletRequest) request : null;
        HttpServletResponse httpResponse = response instanceof HttpServletResponse ? (HttpServletResponse) response
                : null;

        if (httpRequest == null || httpResponse == null) {
            filterChain.doFilter(request, response);
            return;
        }

        boolean isExcludedURL = false;
        for (int i = 0; i < excludedURLs.size(); i++) {
            if (httpRequest.getRequestURL().indexOf(excludedURLs.get(i)) > -1) {
                isExcludedURL = true;
                break;
            }
        }

        if (isExcludedURL) {
            filterChain.doFilter(request, response);
        } else {
            if (UserUtil.validateUserLogin(httpRequest)) {
                filterChain.doFilter(request, response);
            } else {
                httpResponse.sendRedirect(httpRequest.getContextPath() + loginPage);
            }
        }
    }
}

And define the filter, mapping and exclude URLs in web.xml

<filter>
    <filter-name>LoginValidationFilter</filter-name>
    <filter-class>test.LoginValidationFilter</filter-class>
    <init-param>
        <param-name>loginPage</param-name>
        <param-value>/login.jsp</param-value>
    </init-param>
    <init-param>
        <param-name>excludedURLs</param-name>
        <param-value>/admin/;/assets/;/content/;/css/;/js/;/login.jsp;/login.cmd;/logout.cmd;forgot_password.jsp;pageName=</param-value>
    </init-param>
</filter>
<filter-mapping>
    <filter-name>LoginValidationFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>