001/*
002 * This library is part of OpenCms -
003 * the Open Source Content Management System
004 *
005 * Copyright (c) Alkacon Software GmbH & Co. KG (http://www.alkacon.com)
006 *
007 * This library is free software; you can redistribute it and/or
008 * modify it under the terms of the GNU Lesser General Public
009 * License as published by the Free Software Foundation; either
010 * version 2.1 of the License, or (at your option) any later version.
011 *
012 * This library is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
015 * Lesser General Public License for more details.
016 *
017 * For further information about Alkacon Software, please see the
018 * company website: http://www.alkacon.com
019 *
020 * For further information about OpenCms, please see the
021 * project website: http://www.opencms.org
022 *
023 * You should have received a copy of the GNU Lesser General Public
024 * License along with this library; if not, write to the Free Software
025 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
026 */
027
028package org.opencms.staticexport;
029
030import org.opencms.cache.CmsVfsMemoryObjectCache;
031import org.opencms.file.CmsFile;
032import org.opencms.file.CmsObject;
033import org.opencms.file.CmsResource;
034import org.opencms.main.CmsException;
035import org.opencms.main.CmsLog;
036import org.opencms.main.OpenCms;
037import org.opencms.xml.content.CmsXmlContent;
038import org.opencms.xml.content.CmsXmlContentFactory;
039
040import java.net.URI;
041import java.util.ArrayList;
042import java.util.List;
043import java.util.Locale;
044
045import org.apache.commons.logging.Log;
046
047/**
048 * Advanced link substitution behavior.<p>
049 * You can define additional paths that are always used as external links, even if
050 * they point to the same configured site than the OpenCms itself.
051 *
052 * @since 7.5.0
053 *
054 * @see CmsLinkManager#substituteLink(org.opencms.file.CmsObject, String, String, boolean)
055 *      for the method where this handler is used.
056 */
057public class CmsAdvancedLinkSubstitutionHandler extends CmsDefaultLinkSubstitutionHandler {
058
059    /** Filename of the link exclude definition file. */
060    private static final String LINK_EXCLUDE_DEFINIFITON_FILE = "linkexcludes";
061
062    /** The log object for this class. */
063    private static final Log LOG = CmsLog.getLog(CmsAdvancedLinkSubstitutionHandler.class);
064
065    /** XPath for link exclude in definition file. */
066    private static final String XPATH_LINK = "link";
067
068    /**
069     * @see org.opencms.staticexport.CmsDefaultLinkSubstitutionHandler#getLink(org.opencms.file.CmsObject, java.lang.String, java.lang.String, boolean)
070     */
071    @Override
072    public String getLink(CmsObject cms, String link, String siteRoot, boolean forceSecure) {
073
074        if (isExcluded(cms, link)) {
075            return link;
076        }
077        return super.getLink(cms, link, siteRoot, forceSecure);
078    }
079
080    /**
081     * @see org.opencms.staticexport.I_CmsLinkSubstitutionHandler#getRootPath(org.opencms.file.CmsObject, java.lang.String, java.lang.String)
082     */
083    @Override
084    public String getRootPath(CmsObject cms, String targetUri, String basePath) {
085
086        if (cms == null) {
087            // required by unit test cases
088            return targetUri;
089        }
090
091        URI uri;
092        String path;
093
094        // check for malformed URI
095        try {
096            uri = new URI(targetUri);
097            path = uri.getPath();
098        } catch (Exception e) {
099            if (LOG.isWarnEnabled()) {
100                LOG.warn(Messages.get().getBundle().key(Messages.LOG_MALFORMED_URI_1, targetUri), e);
101            }
102            return null;
103        }
104        // opaque URI
105        if (uri.isOpaque()) {
106            return null;
107        }
108
109        // in case the target is the workplace UI
110        if (CmsLinkManager.isWorkplaceUri(uri)) {
111            return null;
112        }
113        if (isExcluded(cms, path)) {
114            return null;
115        }
116
117        return super.getRootPath(cms, targetUri, basePath);
118    }
119
120    /**
121     * Returns if the given path starts with an exclude prefix.<p>
122     *
123     * @param cms the cms context
124     * @param path the path to check
125     *
126     * @return <code>true</code> if the given path starts with an exclude prefix
127     */
128    protected boolean isExcluded(CmsObject cms, String path) {
129
130        List<String> excludes = getExcludes(cms);
131        // now check if the current link start with one of the exclude links
132        for (int i = 0; i < excludes.size(); i++) {
133            if (path.startsWith(excludes.get(i))) {
134                return true;
135            }
136        }
137        return false;
138    }
139
140    /**
141     * Returns the exclude prefix list.<p>
142     *
143     * @param cms the cms context
144     *
145     * @return the exclude prefix list
146     */
147    private List<String> getExcludes(CmsObject cms) {
148
149        // get the list of link excludes form the cache if possible
150        CmsVfsMemoryObjectCache cache = CmsVfsMemoryObjectCache.getVfsMemoryObjectCache();
151        String filePath = OpenCms.getSystemInfo().getConfigFilePath(cms, LINK_EXCLUDE_DEFINIFITON_FILE);
152        @SuppressWarnings("unchecked")
153        List<String> excludes = (List<String>)cache.getCachedObject(cms, filePath);
154        if (excludes == null) {
155            // nothing found in cache, so read definition file and store the result in cache
156            excludes = readLinkExcludes(cms);
157            cache.putCachedObject(cms, filePath, excludes);
158        }
159        return excludes;
160    }
161
162    /**
163     * Reads the link exclude definition file and extracts all excluded links stored in it.<p>
164     *
165     * @param cms the current CmsObject
166     * @return list of Strings, containing link exclude paths
167     */
168    private List<String> readLinkExcludes(CmsObject cms) {
169
170        List<String> linkExcludes = new ArrayList<String>();
171
172        try {
173            // get the link exclude file
174            String filePath = OpenCms.getSystemInfo().getConfigFilePath(cms, LINK_EXCLUDE_DEFINIFITON_FILE);
175            CmsResource res = cms.readResource(filePath);
176            CmsFile file = cms.readFile(res);
177            CmsXmlContent linkExcludeDefinitions = CmsXmlContentFactory.unmarshal(cms, file);
178
179            // get number of excludes
180            int count = linkExcludeDefinitions.getIndexCount(XPATH_LINK, Locale.ENGLISH);
181
182            for (int i = 1; i <= count; i++) {
183
184                String exclude = linkExcludeDefinitions.getStringValue(cms, XPATH_LINK + "[" + i + "]", Locale.ENGLISH);
185                linkExcludes.add(exclude);
186
187            }
188
189        } catch (CmsException e) {
190            LOG.error(e);
191        }
192
193        return linkExcludes;
194    }
195}