RequestUtils.java

package com.jrails.commons.utils;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

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

/**
 * Convenience class for setting and retrieving cookies.
 */
public class RequestUtils {

    private transient static Log log = LogFactory.getLog(RequestUtils.class);

    /**
     * Convenience method to set a cookie
     *
     * @param response
     * @param name
     * @param value
     * @param path
     */
    public static void setCookie(HttpServletResponse response, String name,
                                 String value, String path) {
        if (log.isDebugEnabled()) {
            log.debug("Setting cookie '" + name + "' on path '" + path + "'");
        }
        if (response != null) {
            Cookie cookie = new Cookie(name, value);
            cookie.setSecure(false);
            cookie.setPath(path);
            cookie.setMaxAge(3600 * 24 * 30); // 30 days        
            response.addCookie(cookie);
        }
    }

    /**
     * 写入cookie
     * @param response
     * @param name
     * @param value
     * @param domain
     * @param path
     * @param maxAge
     */
    public static void setCookie(HttpServletResponse response, String name, String value, String domain, String path, int maxAge) {
        if (log.isDebugEnabled()) {
            log.debug("Setting cookie '" + name + "' on path '" + path + "'");
        }
        if (response != null) {
            Cookie cookie = new Cookie(name, value);
            cookie.setSecure(false);
            cookie.setDomain(domain);
            cookie.setPath(path);
            cookie.setMaxAge(maxAge); // 30 days
            response.addCookie(cookie);
        }
    }

    /**
     * Convenience method to get a cookie by name
     *
     * @param request the current request
     * @param name    the name of the cookie to find
     * @return the cookie (if found), null if not found
     */
    public static Cookie getCookie(HttpServletRequest request, String name) {
        Cookie[] cookies = request.getCookies();
        Cookie returnCookie = null;

        if (cookies == null) {
            return returnCookie;
        }

        for (int i = 0; i < cookies.length; i++) {
            Cookie thisCookie = cookies[i];

            if (thisCookie.getName().equals(name)) {
                // cookies with no value do me no good!
                if (!thisCookie.getValue().equals("")) {
                    returnCookie = thisCookie;
                    break;
                }
            }
        }

        return returnCookie;
    }

    /**
     * Convenience method for deleting a cookie by name
     *
     * @param response the current web response
     * @param cookie   the cookie to delete
     * @param path     the path on which the cookie was set (i.e. /appfuse)
     */
    public static void deleteCookie(HttpServletResponse response, Cookie cookie,
                                    String path) {
        if (cookie != null) {
            // Delete the cookie by setting its maximum age to zero
            cookie.setMaxAge(0);
            cookie.setPath(path);
            if (response != null) {
                response.addCookie(cookie);
            }
        }
    }

    /**
     * Convenience method to get the application's URL based on request variables.
     */
    public static String getAppURL(HttpServletRequest request) {
        StringBuffer url = new StringBuffer();
        int port = request.getServerPort();
        if (port < 0) {
            port = 80; // Work around java.net.URL bug
        }
        String scheme = request.getScheme();
        url.append(scheme);
        url.append("://");
        url.append(request.getServerName());
        if ((scheme.equals("http") && (port != 80)) || (scheme.equals("https") && (port != 443))) {
            url.append(':');
            url.append(port);
        }
        url.append(request.getContextPath());
        return url.toString();
    }
}