Filters "/file.jsp" to "/file"

URLFilter.java

package com.bermudez.filter;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.HashSet;

@WebFilter("*")
public class URLFilter implements Filter {
    HashSet<String> invalidExts = new HashSet<String>();

    public void init(FilterConfig filterConfig) throws ServletException {

    }

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse res = (HttpServletResponse) servletResponse;

        String context = req.getContextPath();
        String uri = req.getRequestURI();
        String query = req.getQueryString();

        if(!uri.endsWith("/") && uri.length() > context.length()) {
            if(uri.endsWith(".jsp")) {
                String path = uri.substring(0, uri.lastIndexOf(".jsp"));
                if(query != null && query.length() > 0) {
                    path += "?" + query;
                }
                res.sendRedirect(path);
            } else {
                filterChain.doFilter(req, res);
            }
        } else {
            filterChain.doFilter(req, res);
        }
    }

    public void destroy() {

    }
}