com.gisgraphy.webapp.filter.StaticFilter.java Source code

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Here is the source code for com.gisgraphy.webapp.filter.StaticFilter.java

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/*******************************************************************************
 *   Gisgraphy Project 
 * 
 *   This library 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 2.1 of the License, or (at your option) any later version.
 * 
 *   This library 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 this library; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA
 * 
 *  Copyright 2008  Gisgraphy project 
 *  David Masclet <davidmasclet@gisgraphy.com>
 *  
 *  
 *******************************************************************************/
package com.gisgraphy.webapp.filter;

import java.io.IOException;
import java.util.Iterator;
import java.util.Set;

import javax.servlet.FilterChain;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringUtils;
import org.springframework.util.PatternMatchUtils;
import org.springframework.web.filter.OncePerRequestFilter;
import org.springframework.web.util.UrlPathHelper;

/**
 * A simple filter that allows the application to continue using the .html
 * prefix for actions but also allows static files to be served up with the same
 * extension. Dojo to serve up its HTML template code. The filter works on an
 * include/exclude basis where all requests for active pages are redirected by
 * the filter to thee dispatch servlet. All Dojo related .html requests are
 * allowed to pass straight through to be processed by the servlet container as
 * per normal.
 */
public class StaticFilter extends OncePerRequestFilter {
    private final static String DEFAULT_INCLUDES = "*.html";

    private final static String DEFAULT_EXCLUDES = "";

    private static final String INCLUDES_PARAMETER = "includes";

    private static final String EXCLUDES_PARAMETER = "excludes";

    private static final String SERVLETNAME_PARAMETER = "servletName";

    private String[] excludes;

    private String[] includes;

    private String servletName = null;

    /**
     * Read the includes/excludes paramters and set the filter accordingly.
     */
    @Override
    public void initFilterBean() {
        String includesParam = getFilterConfig().getInitParameter(INCLUDES_PARAMETER);
        if (StringUtils.isEmpty(includesParam)) {
            includes = parsePatterns(DEFAULT_INCLUDES);
        } else {
            includes = parsePatterns(includesParam);
        }

        String excludesParam = getFilterConfig().getInitParameter(EXCLUDES_PARAMETER);
        if (StringUtils.isEmpty(excludesParam)) {
            excludes = parsePatterns(DEFAULT_EXCLUDES);
        } else {
            excludes = parsePatterns(excludesParam);
        }
        // if servletName is specified, set it
        servletName = getFilterConfig().getInitParameter(SERVLETNAME_PARAMETER);
    }

    @SuppressWarnings("unchecked")
    private String[] parsePatterns(String delimitedPatterns) {
        // make sure no patterns are repeated.
        Set<String> patternSet = org.springframework.util.StringUtils.commaDelimitedListToSet(delimitedPatterns);
        String[] patterns = new String[patternSet.size()];
        int i = 0;
        for (Iterator<String> iterator = patternSet.iterator(); iterator.hasNext(); i++) {
            // no trailing/leading white space.
            String pattern = (String) iterator.next();
            patterns[i] = pattern.trim();
        }
        return patterns;
    }

    /**
     * This method checks to see if the current path matches includes or
     * excludes. If it matches includes and not excludes, it forwards to the
     * static resource and ends the filter chain. Otherwise, it forwards to the
     * next filter in the chain.
     * 
     * @param request
     *                the current request
     * @param response
     *                the current response
     * @param chain
     *                the filter chain
     * @throws ServletException
     *                 when something goes wrong
     * @throws IOException
     *                 when something goes terribly wrong
     */
    @Override
    public void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain chain)
            throws IOException, ServletException {

        UrlPathHelper urlPathHelper = new UrlPathHelper();
        String path = urlPathHelper.getPathWithinApplication(request);
        boolean pathExcluded = PatternMatchUtils.simpleMatch(excludes, path);
        boolean pathIncluded = PatternMatchUtils.simpleMatch(includes, path);

        if (pathIncluded && !pathExcluded) {
            if (logger.isDebugEnabled()) {
                logger.debug("Forwarding to static resource: " + path);
            }

            if (path.contains(".html")) {
                response.setContentType("text/html");
            }

            RequestDispatcher rd = getServletContext().getRequestDispatcher(path);
            rd.include(request, response);
            return;
        }

        if (servletName != null) {
            RequestDispatcher rd = getServletContext().getNamedDispatcher(servletName);
            rd.forward(request, response);
            return;
        }

        chain.doFilter(request, response);
    }
}