cmsxmlentityresolver.java

一个cms内容管理平台

     */
    public void cmsEvent(CmsEvent event) {

        CmsResource resource;
        switch (event.getType()) {
            case I_CmsEventListener.EVENT_PUBLISH_PROJECT:
            case I_CmsEventListener.EVENT_CLEAR_CACHES:
                // flush cache   
                m_cacheTemporary.clear();
                m_cacheContentDefinitions.clear();
                if (LOG.isDebugEnabled()) {
                    LOG.debug(Messages.get().getBundle().key(Messages.LOG_ER_FLUSHED_CACHES_0));
                }
                break;
            case I_CmsEventListener.EVENT_RESOURCE_MODIFIED:
                resource = (CmsResource)event.getData().get("resource");
                uncacheSystemId(resource.getRootPath());
                break;
            case I_CmsEventListener.EVENT_RESOURCE_DELETED:
                List resources = (List)event.getData().get("resources");
                for (int i = 0; i < resources.size(); i++) {
                    resource = (CmsResource)resources.get(i);
                    uncacheSystemId(resource.getRootPath());
                }
                break;
            default:
        // no operation
        }
    }

    /**
     * Looks up the given XML content definition system id in the internal content definition cache.<p> 
     * 
     * @param systemId the system id of the XML content definition to look up
     * 
     * @return the XML content definition found, or null if no definition is cached for the given system id
     */
    public CmsXmlContentDefinition getCachedContentDefinition(String systemId) {

        String cacheKey = getCacheKeyForCurrentProject(systemId);
        CmsXmlContentDefinition result = (CmsXmlContentDefinition)m_cacheContentDefinitions.get(cacheKey);
        if ((result != null) && LOG.isDebugEnabled()) {
            LOG.debug(Messages.get().getBundle().key(Messages.LOG_CACHE_LOOKUP_SUCCEEDED_1, cacheKey));
        }
        return result;
    }

    /**
     * @see org.xml.sax.EntityResolver#resolveEntity(java.lang.String, java.lang.String)
     */
    public InputSource resolveEntity(String publicId, String systemId) {

        // lookup the system id caches first
        byte[] content;
        content = (byte[])m_cachePermanent.get(systemId);
        if (content != null) {

            // permanent cache contains system id
            return new InputSource(new ByteArrayInputStream(content));
        } else if (systemId.equals(CmsXmlPage.XMLPAGE_XSD_SYSTEM_ID)) {

            // XML page XSD reference
            try {
                InputStream stream = getClass().getClassLoader().getResourceAsStream(XMLPAGE_XSD_LOCATION);
                content = CmsFileUtil.readFully(stream);
                // cache the XML page DTD
                m_cachePermanent.put(systemId, content);
                return new InputSource(new ByteArrayInputStream(content));
            } catch (Throwable t) {
                LOG.error(Messages.get().getBundle().key(Messages.LOG_XMLPAGE_XSD_NOT_FOUND_1, XMLPAGE_XSD_LOCATION), t);
            }

        } else if (systemId.equals(XMLPAGE_OLD_DTD_SYSTEM_ID_1) || systemId.endsWith(XMLPAGE_OLD_DTD_SYSTEM_ID_2)) {

            // XML page DTD reference
            try {
                InputStream stream = getClass().getClassLoader().getResourceAsStream(XMLPAGE_OLD_DTD_LOCATION);
                // cache the XML page DTD
                content = CmsFileUtil.readFully(stream);
                m_cachePermanent.put(systemId, content);
                return new InputSource(new ByteArrayInputStream(content));
            } catch (Throwable t) {
                LOG.error(
                    Messages.get().getBundle().key(Messages.LOG_XMLPAGE_DTD_NOT_FOUND_1, XMLPAGE_OLD_DTD_LOCATION),
                    t);
            }
        } else if ((m_cms != null) && systemId.startsWith(OPENCMS_SCHEME)) {

            // opencms:// VFS reference
            String cacheSystemId = systemId.substring(OPENCMS_SCHEME.length() - 1);
            String cacheKey = getCacheKey(cacheSystemId, m_cms.getRequestContext().currentProject().isOnlineProject());
            // look up temporary cache
            content = (byte[])m_cacheTemporary.get(cacheKey);
            if (content != null) {
                return new InputSource(new ByteArrayInputStream(content));
            }
            try {
                // content not cached, read from VFS
                m_cms.getRequestContext().saveSiteRoot();
                m_cms.getRequestContext().setSiteRoot("/");
                CmsFile file = m_cms.readFile(cacheSystemId);
                content = file.getContents();
                // store content in cache
                m_cacheTemporary.put(cacheKey, content);
                if (LOG.isDebugEnabled()) {
                    LOG.debug(Messages.get().getBundle().key(Messages.LOG_ER_CACHED_SYS_ID_1, cacheKey));
                }
                return new InputSource(new ByteArrayInputStream(content));
            } catch (Throwable t) {
                LOG.error(Messages.get().getBundle().key(Messages.LOG_ENTITY_RESOLVE_FAILED_1, systemId), t);
            } finally {
                m_cms.getRequestContext().restoreSiteRoot();
            }
        } else if (systemId.substring(0, systemId.lastIndexOf("/") + 1).equalsIgnoreCase(
            CmsConfigurationManager.DEFAULT_DTD_PREFIX)) {

            // default DTD location in the org.opencms.configuration package
            String location = null;
            try {
                String dtdFilename = systemId.substring(systemId.lastIndexOf("/") + 1);
                location = CmsConfigurationManager.DEFAULT_DTD_LOCATION + dtdFilename;
                InputStream stream = getClass().getClassLoader().getResourceAsStream(location);
                content = CmsFileUtil.readFully(stream);
                // cache the DTD
                m_cachePermanent.put(systemId, content);
                return new InputSource(new ByteArrayInputStream(content));
            } catch (Throwable t) {
                LOG.error(Messages.get().getBundle().key(Messages.LOG_DTD_NOT_FOUND_1, location), t);
            }

        }

        // use the default behaviour (i.e. resolve through external URL)
        return null;
    }

    /**
     * Returns a cache key for the given system id (filename) based on the status 
     * of the given project flag.<p>
     * 
     * @param systemId the system id (filename) to get the cache key for
     * @param online indicates if this key is generated for the online project
     * 
     * @return the cache key for the system id
     */
    private String getCacheKey(String systemId, boolean online) {

        if (online) {
            return "online_".concat(systemId);
        }
        return "offline_".concat(systemId);
    }

    /**
     * Returns a cache key for the given system id (filename) based on the status 
     * of the internal CmsObject.<p>
     * 
     * @param systemId the system id (filename) to get the cache key for
     * 
     * @return the cache key for the system id
     */
    private String getCacheKeyForCurrentProject(String systemId) {

        // check the project
        boolean project = (m_cms != null) ? m_cms.getRequestContext().currentProject().isOnlineProject() : false;

        // remove opencms:// prefix
        if (systemId.startsWith(OPENCMS_SCHEME)) {
            systemId = systemId.substring(OPENCMS_SCHEME.length() - 1);
        }

        return getCacheKey(systemId, project);
    }

    /**
     * Uncaches a system id (filename) from the internal offline temporary and content defintions caches.<p>
     * 
     * The online resources cached for the online project are only flushed when a project is published.<p>
     * 
     * @param systemId the system id (filename) to uncache
     */
    private void uncacheSystemId(String systemId) {

        Object o;
        o = m_cacheTemporary.remove(getCacheKey(systemId, false));
        if (null != o) {
            // if an object was removed from the tomporary cache, all XML content definitions must be cleared
            // because this may be a nested subschema 
            m_cacheContentDefinitions.clear();
            if (LOG.isDebugEnabled()) {
                LOG.debug(Messages.get().getBundle().key(
                    Messages.LOG_ER_UNCACHED_SYS_ID_1,
                    getCacheKey(systemId, false)));
            }
        } else {
            // check if a cached content definition has to be removed based on the system id
            o = m_cacheContentDefinitions.remove(getCacheKey(systemId, false));
            if ((null != o) && LOG.isDebugEnabled()) {
                LOG.debug(Messages.get().getBundle().key(
                    Messages.LOG_ER_UNCACHED_CONTENT_DEF_1,
                    getCacheKey(systemId, false)));
            }
        }
    }
}