cmslinkmanager.java

cms是开源的框架

/*
 * File   : $Source: /usr/local/cvs/opencms/src/org/opencms/staticexport/CmsLinkManager.java,v $
 * Date   : $Date: 2006/04/28 15:20:52 $
 * Version: $Revision: 1.61 $
 *
 * This library is part of OpenCms -
 * the Open Source Content Mananagement System
 *
 * Copyright (c) 2005 Alkacon Software GmbH (http://www.alkacon.com)
 *
 * 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 2.1 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.
 *
 * For further information about Alkacon Software GmbH, please see the
 * company website: http://www.alkacon.com
 *
 * For further information about OpenCms, please see the
 * project website: http://www.opencms.org
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

package org.opencms.staticexport;

import org.opencms.file.CmsObject;
import org.opencms.file.types.CmsResourceTypeImage;
import org.opencms.main.CmsException;
import org.opencms.main.CmsLog;
import org.opencms.main.OpenCms;
import org.opencms.site.CmsSite;
import org.opencms.site.CmsSiteManager;
import org.opencms.site.CmsSiteMatcher;
import org.opencms.util.CmsStringUtil;
import org.opencms.validation.CmsPointerLinkValidationResult;
import org.opencms.workplace.CmsWorkplace;

import java.net.MalformedURLException;
import java.net.URI;
import java.net.URL;

import org.apache.commons.logging.Log;

/**
 * Does the link replacement for the &lg;link&gt; tags.<p> 
 *
 * Since this functionality is closely related to the static export,
 * this class resides in the static export package.<p>
 *
 * @author Alexander Kandzior 
 * 
 * @version $Revision: 1.61 $ 
 * 
 * @since 6.0.0 
 */
public class CmsLinkManager {

    /** The log object for this class. */
    private static final Log LOG = CmsLog.getLog(CmsLinkManager.class);

    /** Base URL to calculate absolute links. */
    private static URL m_baseUrl;

    /** Stores the results of a extern link validation. */
    private CmsPointerLinkValidationResult m_pointerLinkValidationResult;

    /**
     * Public constructor.<p>
     */
    public CmsLinkManager() {

        // empty
    }

    /**
     * Static initializer for the base URL.<p>
     */
    static {
        m_baseUrl = null;
        try {
            m_baseUrl = new URL("http://127.0.0.1");
        } catch (MalformedURLException e) {
            // this won't happen
        }
    }

    /**
     * Calculates the absolute uri for the "relativeUri" with the given absolute "baseUri" as start. <p> 
     * 
     * If "relativeUri" is already absolute, it is returned unchanged.
     * This method also returns "relativeUri" unchanged if it is not well-formed.<p>
     *    
     * @param relativeUri the relative uri to calculate an absolute uri for
     * @param baseUri the base uri, this must be an absolute uri
     * @return an absolute uri calculated from "relativeUri" and "baseUri"
     */
    public static String getAbsoluteUri(String relativeUri, String baseUri) {

        if ((relativeUri == null) || (relativeUri.length() >= 1 && relativeUri.charAt(0) == '/')) {
            // uri is null or already absolute
            return relativeUri;
        }
        try {
            URL url = new URL(new URL(m_baseUrl, baseUri), relativeUri);
            if (url.getQuery() == null) {
                return url.getPath();
            } else {
                StringBuffer result = new StringBuffer(url.getPath().length() + url.getQuery().length() + 2);
                result.append(url.getPath());
                result.append('?');
                result.append(url.getQuery());
                return result.toString();
            }
        } catch (MalformedURLException e) {
            return relativeUri;
        }
    }

    /**
     * Calculates a realtive uri from "fromUri" to "toUri",
     * both uri's must be absolute.<p>
     * 
     * @param fromUri the uri to start
     * @param toUri the uri to calculate a relative path to
     * @return a realtive uri from "fromUri" to "toUri"
     */
    public static String getRelativeUri(String fromUri, String toUri) {

        StringBuffer result = new StringBuffer();
        int pos = 0;

        while (true) {
            int i = fromUri.indexOf('/', pos);
            int j = toUri.indexOf('/', pos);
            if ((i == -1) || (i != j) || !fromUri.regionMatches(pos, toUri, pos, i - pos)) {
                break;
            }
            pos = i + 1;
        }

        // count hops up from here to the common ancestor
        for (int i = fromUri.indexOf('/', pos); i > 0; i = fromUri.indexOf('/', i + 1)) {
            result.append("../");
        }

        // append path down from common ancestor to there
        result.append(toUri.substring(pos));
        return result.toString();
    }

    /**
     * Returns the site path for a given uri.<p>
     * 
     * If the uri contains no site information, but starts with the opencms context, the context is removed.<p>
     * <code>/opencms/opencms/system/further_path -> /system/further_path</code>
     * 
     * If the uri contains no site information, the path will be prefixed with the current site
     * (if mysite is the site currently selected in the workplace or in the request).<p>
     * <pre>
     * /folder/page.html -> /sites/mysite/folder/page.html
     * </pre>
     *  
     * If the path of the uri is relative, i.e. does not start with "/", 
     * the path will be prefixed with the current site and the given relative path,
     * then normalized.
     * If no relative path is given, null is returned.
     * If the normalized path is outsite a site, null is returned.<p>
     * <pre>
     * page.html -> /sites/mysite/{relativePath}/page.html
     * ../page.html -> /sites/mysite/page.html
     * ../../page.html -> null
     * </pre>
     * 
     * If the uri contains a scheme/server name that denotes an opencms site, 
     * it is replaced by the appropriate site path.<p>
     * <pre>
     * http://www.mysite.de/folder/page.html -> /sites/mysite/folder/page.html
     * </pre>
     * 
     * If the uri contains a scheme/server name that does not match with any site, 
     * or if the uri is opaque or invalid,
     * null is returned.<p>
     * <pre>
     * http://www.elsewhere.com/page.html -> null
     * mailto:[e-mail] -> null
     * </pre>
     * 
     * @param cms the cms object
     * @param relativePath path to use as prefix if neccessary
     * @param targetUri the target uri
     * @return the root path for the target uri or null
     */
    public static String getSitePath(CmsObject cms, String relativePath, String targetUri) {

        if (cms == null) {
            // required by unit test cases
            return targetUri;
        }

        URI uri;
        String path;
        String fragment;
        String query;
        String suffix;

        // malformed uri
        try {

            uri = new URI(targetUri);
            path = uri.getPath();

            fragment = uri.getFragment();
            if (fragment != null) {
                fragment = "#" + fragment;
            } else {
                fragment = "";
            }

            query = uri.getQuery();
            if (query != null) {
                query = "?" + query;
            } else {
                query = "";
            }

        } catch (Exception e) {
            if (LOG.isWarnEnabled()) {
                LOG.warn(Messages.get().getBundle().key(Messages.LOG_MALFORMED_URI_1, targetUri), e);
            }
            return null;
        }

        // concat fragment and query 
        suffix = fragment.concat(query);

        // opaque URI
        if (uri.isOpaque()) {
            return null;
        }

        // absolute URI (i.e. uri has a scheme component like http:// ...)
        if (uri.isAbsolute()) {
            CmsSiteMatcher matcher = new CmsSiteMatcher(targetUri);
            if (OpenCms.getSiteManager().isMatching(matcher)) {
                if (path.startsWith(OpenCms.getSystemInfo().getOpenCmsContext())) {
                    path = path.substring(OpenCms.getSystemInfo().getOpenCmsContext().length());
                }

                return cms.getRequestContext().addSiteRoot(
                    OpenCms.getSiteManager().matchSite(matcher).getSiteRoot(),
                    path + suffix);
            } else {
                return null;
            }
        }

        // relative URI (i.e. no scheme component, but filename can still start with "/") 
        String context = OpenCms.getSystemInfo().getOpenCmsContext();
        if ((context != null) && path.startsWith(context)) {
            // URI is starting with opencms context

            String siteRoot = null;
            if (relativePath != null) {
                siteRoot = CmsSiteManager.getSiteRoot(relativePath);
            }

            // cut context from path
            path = path.substring(context.length());

            if (siteRoot != null) {
                // special case: relative path contains a site root, i.e. we are in the root site                
                if (!path.startsWith(siteRoot)) {
                    // path does not already start with the site root, we have to add this path as site prefix
                    return cms.getRequestContext().addSiteRoot(siteRoot, path + suffix);
                } else {