JsfRedirectStrategy.java

/*
 * Copyright 2004-2012 ICEsoft Technologies Canada Corp.
 *
 * 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.algaworks.pedidovenda.security;


import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.security.web.RedirectStrategy;
import org.springframework.security.web.util.UrlUtils;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

/**
 * This class extends the default redirect strategy provided by
 * Spring Security 3.1m2
 *
 * @author Ben Simpson <ben.simpson@icesoft.com.com>
 *         Date: 2/9/11
 *         Time: 2:51 PM
 */
public class JsfRedirectStrategy implements RedirectStrategy {

    protected final Log logger = LogFactory.getLog(getClass());

    private boolean contextRelative;


    /**
     * Redirects the response to the supplied URL.
     * <p>
     * If <tt>contextRelative</tt> is set, the redirect value will be the value after the request context path. Note
     * that this will result in the loss of protocol information (HTTP or HTTPS), so will cause problems if a
     * redirect is being performed to change to HTTPS, for example.
     */
    public void sendRedirect(HttpServletRequest request, HttpServletResponse response, String url) throws IOException {
        String redirectUrl = calculateRedirectUrl(request.getContextPath(), url);
        redirectUrl = response.encodeRedirectURL(redirectUrl);

        if (logger.isDebugEnabled()) {
            logger.debug("Redirecting to '" + redirectUrl + "'");
        }

        //we should redirect using ajax response if the case warrants
        boolean ajaxRedirect = request.getHeader("faces-request") != null
                && request.getHeader("faces-request").toLowerCase().indexOf("ajax") > -1;

        if (ajaxRedirect) {
            //javax.faces.context.FacesContext ctxt = javax.faces.context.FacesContext.getCurrentInstance();
            //ctxt.getExternalContext().redirect(redirectUrl);

            String ajaxRedirectXml = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>" +
                "<partial-response><redirect url=\""+redirectUrl+"\"></redirect></partial-response>";
            response.setContentType("text/xml");
            response.getWriter().write(ajaxRedirectXml);
        } else {
            response.sendRedirect(redirectUrl);
        }


    }

    private String calculateRedirectUrl(String contextPath, String url) {
        if (!UrlUtils.isAbsoluteUrl(url)) {
            if (contextRelative) {
                return url;
            } else {
                return contextPath + url;
            }
        }

        // Full URL, including http(s)://

        if (!contextRelative) {
            return url;
        }

        // Calculate the relative URL from the fully qualified URL, minus the scheme and base context.
        url = url.substring(url.indexOf("://") + 3); // strip off scheme
        url = url.substring(url.indexOf(contextPath) + contextPath.length());

        if (url.length() > 1 && url.charAt(0) == '/') {
            url = url.substring(1);
        }

        return url;
    }

    /**
     * If <tt>true</tt>, causes any redirection URLs to be calculated minus the protocol
     * and context path (defaults to <tt>false</tt>).
     */
    public void setContextRelative(boolean useRelativeContext) {
        this.contextRelative = useRelativeContext;
    }
}