dk.dma.msinm.common.util.WebUtils.java Source code

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Here is the source code for dk.dma.msinm.common.util.WebUtils.java

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/* Copyright (c) 2011 Danish Maritime Authority
 *
 * 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 3 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 General Public License
 * along with this library.  If not, see <http://www.gnu.org/licenses/>.
 */
package dk.dma.msinm.common.util;

import org.apache.commons.lang.ArrayUtils;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;

/**
 * Web-related utility functions
 */
public class WebUtils {

    private WebUtils() {
    }

    /**
     * Returns the base URL of the request
     * @param request the request
     * @return the base URL
     */
    public static String getWebAppUrl(HttpServletRequest request, String... appends) {
        String result = String.format("%s://%s%s%s", request.getScheme(), request.getServerName(),
                request.getServerPort() == 80 || request.getServerPort() == 443 ? ""
                        : ":" + request.getServerPort(),
                request.getContextPath());
        for (String a : appends) {
            result = result + a;
        }
        return result;
    }

    /**
     * Returns the base URL of the request
     * @param request the request
     * @return the base URL
     */
    public static String getServletUrl(HttpServletRequest request, String... appends) {
        String[] args = (String[]) ArrayUtils.addAll(new String[] { request.getServletPath() }, appends);
        return getWebAppUrl(request, args);
    }

    /**
     * Returns the cookie with the given name or null if not found
     * @param request the request
     * @param name the name
     * @return the cookie with the given name or null if not found
     */
    public static Cookie getCookie(HttpServletRequest request, String name) {
        Cookie[] cookies = request.getCookies();
        if (cookies != null) {
            for (Cookie c : request.getCookies()) {
                if (c.getName().equals(name)) {
                    return c;
                }
            }
        }
        return null;
    }

    /**
     * Returns the value of the cookie with the given name or null if not found
     * @param request the request
     * @param name the name
     * @return the value of the cookie with the given name or null if not found
     */
    public static String getCookieValue(HttpServletRequest request, String name) {
        Cookie c = getCookie(request, name);
        return (c == null) ? null : c.getValue();
    }

    /**
     * Reads the body of a posted request
     * @param request the request
     * @return the body
     */
    public static String readRequestBody(HttpServletRequest request) throws IOException {
        StringBuilder result = new StringBuilder();

        String line;
        BufferedReader reader = request.getReader();
        while ((line = reader.readLine()) != null) {
            result.append(line).append("\n");
        }

        return result.toString();
    }

    /**
     * Add headers to the response to ensure no caching takes place
     * @param response the response
     * @return the response
     */
    public static HttpServletResponse nocache(HttpServletResponse response) {
        response.setHeader("Cache-Control", "no-cache");
        response.setHeader("Cache-Control", "no-store");
        response.setHeader("Pragma", "no-cache");
        response.setDateHeader("Expires", 0);
        return response;
    }

    /**
     * Add headers to the response to ensure caching in the given duration
     * @param response the response
     * @param seconds the number of seconds to cache the response
     * @return the response
     */
    public static HttpServletResponse cache(HttpServletResponse response, int seconds) {
        long now = System.currentTimeMillis();
        response.addHeader("Cache-Control", "max-age=" + seconds);
        response.setDateHeader("Last-Modified", now);
        response.setDateHeader("Expires", now + seconds * 1000L);
        return response;
    }

    /**
     * Encode identically to the javascript encodeURIComponent() method
     * @param s the string to encode
     * @return the encoded string
     */
    public static String encodeURIComponent(String s) {
        String result;

        try {
            result = URLEncoder.encode(s, "UTF-8").replaceAll("\\+", "%20").replaceAll("\\%21", "!")
                    .replaceAll("\\%27", "'").replaceAll("\\%28", "(").replaceAll("\\%29", ")")
                    .replaceAll("\\%7E", "~");
        } catch (UnsupportedEncodingException e) {
            result = s;
        }

        return result;
    }

    /**
     * Encode identically to the javascript encodeURI() method
     * @param s the string to encode
     * @return the encoded string
     */
    public static String encodeURI(String s) {
        return encodeURIComponent(s).replaceAll("\\%3A", ":").replaceAll("\\%2F", "/").replaceAll("\\%3B", ";")
                .replaceAll("\\%3F", "?");
    }
}