com.data2semantics.yasgui.server.servlets.AppCacheServlet.java Source code

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Here is the source code for com.data2semantics.yasgui.server.servlets.AppCacheServlet.java

Source

package com.data2semantics.yasgui.server.servlets;

/*
 * #%L
 * YASGUI
 * %%
 * Copyright (C) 2013 Laurens Rietveld
 * %%
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * 
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 * #L%
 */

import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;

import javax.servlet.ServletException;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.io.IOUtils;

import com.data2semantics.yasgui.shared.CookieKeys;

public class AppCacheServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        String strongName = getPermutationFromCookies(request.getCookies());

        if (strongName != null && strongName.length() > 0) {
            boolean getCount = request.getParameterMap().keySet().contains("count");

            response.setHeader("Cache-Control", "no-cache");
            response.setHeader("Pragma", "no-cache");
            response.setDateHeader("Expires", new Date().getTime());

            String moduleDir = getServletContext().getRealPath("/Yasgui/");
            String appcacheFile = moduleDir + "/" + strongName;
            if (fetchManifestForDev(request)) {
                appcacheFile += ".dev";
            }
            appcacheFile += ".appcache";
            String manifestString = IOUtils.toString(new FileReader(appcacheFile));

            PrintWriter out = response.getWriter();
            if (getCount) {
                out.println(Integer.toString(getCacheCount(manifestString)));
            } else {
                response.setContentType("text/cache-manifest");
                out.println(manifestString);

            }
            out.close();
        }

    }

    private int getCacheCount(String manifestString) {
        //remove the network/fallback stuff
        manifestString = manifestString.replaceAll("(NETWORK|FALLBACK):((?!(NETWORK|FALLBACK|CACHE):)[\\w\\W]*)",
                "");

        //remove the comments
        manifestString = manifestString.replaceAll("#[^\\r\\n]*(\\r\\n?|\\n)", "");

        //remove the CACHE: thing
        manifestString = manifestString.replace("CACHE:", "");

        //Strip out the cache manifest header and empty lines
        manifestString = manifestString.replaceAll("CACHE MANIFEST\\s*|\\s*$", "");

        return manifestString.split("\r\n|\r|\n").length;
    }

    private boolean fetchManifestForDev(HttpServletRequest request) {
        String type = request.getParameter("type");
        boolean fetchForDev = false;
        if (type != null && type.equals("dev"))
            fetchForDev = true;

        return fetchForDev;
    }

    private String getPermutationFromCookies(Cookie[] cookies) {
        String permutationStrongName = null;
        for (Cookie cookie : cookies) {
            if (cookie.getName().equals(CookieKeys.GWT_STRONG_NAME)) {
                permutationStrongName = cookie.getValue();
            }
        }
        return permutationStrongName;

    }

}