it.attocchi.web.filters.IE7VersionFilter.java Source code

Introduction

Here is the source code for it.attocchi.web.filters.IE7VersionFilter.java

Source

/*
Copyright (c) Twig (http://twigstechtips.blogspot.it/2010/03/css-ie8-meta-tag-to-disable.html)
       
This file is part of WebAppCommon.
    
WebAppCommon is free software: you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
WebAppCommon is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.
    
You should have received a copy of the GNU Lesser General Public License
along with WebAppCommon.  If not, see <http://www.gnu.org/licenses/>.
 */

package it.attocchi.web.filters;

import java.io.IOException;

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;

import org.apache.commons.lang3.StringUtils;
import org.apache.log4j.Logger;

/*
 * Usage on web.xml:
 * 
 *    
 <!-- IE7VersionFilter -->
 <filter>
 <display-name>IE7VersionFilter</display-name>
 <filter-name>IE7VersionFilter</filter-name>
 <filter-class>it.attocchi.web.filters.IE7VersionFilter</filter-class>
 </filter>
 <filter-mapping>
 <filter-name>IE7VersionFilter</filter-name>
 <servlet-name>Faces Servlet</servlet-name>
 </filter-mapping>
 <!-- IE7VersionFilter -->
    
 */
public class IE7VersionFilter implements Filter {

    protected final Logger logger = Logger.getLogger(this.getClass().getName());

    String pathToBeIgnored;
    String userAgentMatch;
    String xuacompatible;

    @Override
    public void destroy() {

    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
            throws IOException, ServletException {
        HttpServletRequest httpRequest = (HttpServletRequest) request;
        HttpServletResponse httpResponse = (HttpServletResponse) response;

        logger.debug("IE7VersionFilter");

        String path = httpRequest.getRequestURI();
        // if (path.startsWith("/specialpath")) {
        if (pathToBeIgnored != null && wildCardMatch(path, pathToBeIgnored)) {
            logger.debug("IE7VersionFilter not applied for " + path);
            chain.doFilter(request, response); // Just continue chain.
        } else {
            // Do your business stuff here for all paths other than
            // /specialpath.
            /*
             * http://twigstechtips.blogspot.com/2010/03/css-ie8-meta-tag-to-disable
             * .html
             */

            String userAgent = httpRequest.getHeader("User-Agent");
            if (StringUtils.isBlank(userAgentMatch) || userAgent.contains(userAgentMatch)) {
                logger.debug("IE7VersionFilter applied agent " + userAgent);
                // "IE=EmulateIE7"
                httpResponse.setHeader("X-UA-Compatible", xuacompatible);
            } else {
                logger.debug("IE7VersionFilter not applied for agent " + userAgent);
            }

            chain.doFilter(request, response);
        }

    }

    @Override
    public void init(FilterConfig config) throws ServletException {
        pathToBeIgnored = config.getInitParameter("pathToBeIgnored");
        userAgentMatch = config.getInitParameter("userAgentMatch");
        xuacompatible = config.getInitParameter("X-UA-Compatible");
    }

    /**
     * Performs a wildcard matching for the text and pattern provided.
     * 
     * @param text
     *            the text to be tested for matches.
     * 
     * @param pattern
     *            the pattern to be matched for. This can contain the wildcard
     *            character '*' (asterisk).
     * 
     * @return <tt>true</tt> if a match is found, <tt>false</tt> otherwise.
     */

    public static boolean wildCardMatch(String text, String pattern) {
        // Create the cards by splitting using a RegEx. If more speed
        // is desired, a simpler character based splitting can be done.
        String[] cards = pattern.split("\\*");

        // Iterate over the cards.
        for (String card : cards) {
            int idx = text.indexOf(card);

            // Card not detected in the text.
            if (idx == -1) {
                return false;
            }

            // Move ahead, towards the right of the text.
            text = text.substring(idx + card.length());
        }

        return true;
    }

}