com.meltmedia.cadmium.servlets.RedirectFilter.java Source code

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Here is the source code for com.meltmedia.cadmium.servlets.RedirectFilter.java

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/**
 *    Copyright 2012 meltmedia
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
package com.meltmedia.cadmium.servlets;

import com.meltmedia.cadmium.core.meta.Redirect;
import com.meltmedia.cadmium.core.meta.RedirectConfigProcessor;

import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.inject.Inject;
import javax.inject.Singleton;
import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;

@Singleton
public class RedirectFilter implements Filter {
    private final Logger log = LoggerFactory.getLogger(getClass());

    @Inject
    protected RedirectConfigProcessor redirect;

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest req, ServletResponse resp, FilterChain chain)
            throws IOException, ServletException {
        Redirect redir = null;
        try {
            if (redirect != null && req instanceof HttpServletRequest && resp instanceof HttpServletResponse) {
                HttpServletRequest request = (HttpServletRequest) req;
                HttpServletResponse response = (HttpServletResponse) resp;
                String path = request.getRequestURI();
                String queryString = request.getQueryString();
                log.trace("Checking for existing redirect [{}?{}]", path, queryString);
                redir = redirect.requestMatches(path, queryString);
                if (redir != null) {
                    String redirectTo = redir.getUrlSubstituted();
                    if (StringUtils.isNotBlank(queryString) && !redirectTo.contains("?")) {

                        redirectTo += "?" + queryString;
                        log.debug("adding query string to redirect path: {}", redirectTo);
                    }
                    response.setHeader("Location", redirectTo);
                    response.setStatus(HttpServletResponse.SC_MOVED_PERMANENTLY);
                    log.debug("Location response header: {}", redirectTo);
                    return;
                }
            } else {
                log.trace("Redirect and/or req and resp are not http");
            }
            try {
                chain.doFilter(req, resp);
            } catch (IOException ioe) {
                log.trace("Failed down stream from redirect filter.", ioe);
                throw ioe;
            } catch (ServletException se) {
                log.trace("Failed down stream from redirect filter.", se);
                throw se;
            } catch (Throwable t) {
                StringWriter str = new StringWriter();
                t.printStackTrace(new PrintWriter(str));
                log.trace("Failed down stream from redirect filter: " + str.toString(), t);
                ServletException se = new ServletException(t);
                throw se;

            }
        } catch (Throwable t) {
            StringWriter str = new StringWriter();
            t.printStackTrace(new PrintWriter(str));
            log.debug("Failed in redirect filter: " + str.toString(), t);
            ServletException se = new ServletException(t);
            throw se;
        }
    }

    @Override
    public void destroy() {

    }

}