org.opencms.importexport.CmsExport.java Source code

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/*
 * This library is part of OpenCms -
 * the Open Source Content Management System
 *
 * Copyright (c) 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.importexport;

import org.opencms.db.CmsResourceState;
import org.opencms.file.CmsFile;
import org.opencms.file.CmsFolder;
import org.opencms.file.CmsGroup;
import org.opencms.file.CmsObject;
import org.opencms.file.CmsProject;
import org.opencms.file.CmsProperty;
import org.opencms.file.CmsResource;
import org.opencms.file.CmsResourceFilter;
import org.opencms.file.CmsUser;
import org.opencms.file.CmsVfsException;
import org.opencms.file.CmsVfsResourceNotFoundException;
import org.opencms.i18n.CmsMessageContainer;
import org.opencms.main.CmsEvent;
import org.opencms.main.CmsException;
import org.opencms.main.CmsLog;
import org.opencms.main.I_CmsEventListener;
import org.opencms.main.OpenCms;
import org.opencms.relations.CmsRelation;
import org.opencms.relations.CmsRelationFilter;
import org.opencms.report.I_CmsReport;
import org.opencms.security.CmsAccessControlEntry;
import org.opencms.security.CmsOrganizationalUnit;
import org.opencms.security.CmsRole;
import org.opencms.security.CmsRoleViolationException;
import org.opencms.util.CmsDataTypeUtil;
import org.opencms.util.CmsDateUtil;
import org.opencms.util.CmsFileUtil;
import org.opencms.util.CmsUUID;
import org.opencms.util.CmsXmlSaxWriter;
import org.opencms.workplace.CmsWorkplace;

import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.apache.commons.codec.binary.Base64;
import org.apache.commons.logging.Log;

import org.dom4j.Document;
import org.dom4j.DocumentHelper;
import org.dom4j.Element;
import org.dom4j.io.SAXWriter;
import org.xml.sax.SAXException;

/**
 * Provides the functionality to export files from the OpenCms VFS to a ZIP file.<p>
 * 
 * The ZIP file written will contain a copy of all exported files with their contents.
 * It will also contain a <code>manifest.xml</code> file in which all meta-information 
 * about this files are stored, like permissions etc.<p>
 * 
 * @since 6.0.0 
 */
public class CmsExport {

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

    /** Counter for the export. */
    private int m_exportCount;

    /** Set of all exported files, required for preventing redundant sibling export. */
    private Set<CmsUUID> m_exportedResources;

    /** The export parameters. */
    private CmsExportParameters m_parameters;

    /** The top level file node where all resources are appended to. */
    private Element m_resourceNode;

    /** The SAX writer to write the output to. */
    private SAXWriter m_saxWriter;

    /** Cache for previously added super folders. */
    private List<String> m_superFolders;

    /** The export writer. */
    private CmsExportHelper m_exportWriter;

    /**
     * Constructs a new uninitialized export, required for special subclass data export.<p>
     */
    public CmsExport() {

        // empty constructor
    }

    /** The cms context. */
    private CmsObject m_cms;

    /** The report. */
    private I_CmsReport m_report;

    /**
     * Constructs a new export.<p>
     * 
     * @param cms the cms context 
     * @param report the report
     *
     * @throws CmsRoleViolationException if the current user has not the required role
     */
    public CmsExport(CmsObject cms, I_CmsReport report) throws CmsRoleViolationException {

        m_cms = cms;
        m_report = report;

        // check if the user has the required permissions
        OpenCms.getRoleManager().checkRole(getCms(), CmsRole.DATABASE_MANAGER);

    }

    /**
     * Export the data.<p>
     * 
     * @param parameters the export parameters
     * 
     * @throws CmsImportExportException if something goes wrong 
     */
    public void exportData(CmsExportParameters parameters) throws CmsImportExportException {

        m_parameters = parameters;
        m_exportCount = 0;

        // clear all caches
        getReport().println(Messages.get().container(Messages.RPT_CLEARCACHE_0), I_CmsReport.FORMAT_NOTE);
        OpenCms.fireCmsEvent(new CmsEvent(I_CmsEventListener.EVENT_CLEAR_CACHES, new HashMap<String, Object>(0)));

        try {
            Element exportNode = openExportFile();

            if (m_parameters.getModuleInfo() != null) {
                // add the module element
                exportNode.add(m_parameters.getModuleInfo());
                // write the XML
                digestElement(exportNode, m_parameters.getModuleInfo());
            }

            // export account data only if selected
            if (m_parameters.isExportAccountData()) {
                Element accountsElement = exportNode.addElement(CmsImportVersion7.N_ACCOUNTS);
                getSaxWriter().writeOpen(accountsElement);

                exportOrgUnits(accountsElement);

                getSaxWriter().writeClose(accountsElement);
                exportNode.remove(accountsElement);
            }

            // export resource data only if selected
            if (m_parameters.isExportResourceData()) {
                exportAllResources(exportNode, m_parameters.getResources());
            }

            // export project data only if selected
            if (m_parameters.isExportProjectData()) {
                Element projectsElement = exportNode.addElement(CmsImportVersion7.N_PROJECTS);
                getSaxWriter().writeOpen(projectsElement);

                exportProjects(projectsElement);

                getSaxWriter().writeClose(projectsElement);
                exportNode.remove(projectsElement);
            }

            closeExportFile(exportNode);
        } catch (SAXException se) {
            getReport().println(se);

            CmsMessageContainer message = Messages.get()
                    .container(Messages.ERR_IMPORTEXPORT_ERROR_EXPORTING_TO_FILE_1, getExportFileName());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), se);
            }

            throw new CmsImportExportException(message, se);
        } catch (IOException ioe) {
            getReport().println(ioe);

            CmsMessageContainer message = Messages.get()
                    .container(Messages.ERR_IMPORTEXPORT_ERROR_EXPORTING_TO_FILE_1, getExportFileName());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), ioe);
            }

            throw new CmsImportExportException(message, ioe);
        }
    }

    /**
     * Exports the given folder and all child resources.<p>
     *
     * @param folderName to complete path to the resource to export
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     * @throws IOException if not all resources could be appended to the ZIP archive
     */
    protected void addChildResources(String folderName) throws CmsImportExportException, IOException, SAXException {

        try {
            // get all subFolders
            List<CmsResource> subFolders = getCms().getSubFolders(folderName, CmsResourceFilter.IGNORE_EXPIRATION);
            // get all files in folder
            List<CmsResource> subFiles = getCms().getFilesInFolder(folderName, CmsResourceFilter.IGNORE_EXPIRATION);

            // walk through all files and export them
            for (int i = 0; i < subFiles.size(); i++) {
                CmsResource file = subFiles.get(i);
                CmsResourceState state = file.getState();
                long age = file.getDateLastModified() < file.getDateCreated() ? file.getDateCreated()
                        : file.getDateLastModified();

                if (getCms().getRequestContext().getCurrentProject().isOnlineProject()
                        || (m_parameters.isIncludeUnchangedResources()) || state.isNew() || state.isChanged()) {
                    if (!state.isDeleted() && !CmsWorkplace.isTemporaryFile(file)
                            && (age >= m_parameters.getContentAge())) {
                        String export = getCms().getSitePath(file);
                        if (checkExportResource(export)) {
                            if (isInExportableProject(file)) {
                                exportFile(getCms().readFile(export, CmsResourceFilter.IGNORE_EXPIRATION));
                            }
                        }
                    }
                }
                // release file header memory
                subFiles.set(i, null);
            }
            // all files are exported, release memory
            subFiles = null;

            // walk through all subfolders and export them
            for (int i = 0; i < subFolders.size(); i++) {
                CmsResource folder = subFolders.get(i);
                if (folder.getState() != CmsResource.STATE_DELETED) {
                    // check if this is a system-folder and if it should be included.
                    String export = getCms().getSitePath(folder);
                    if (checkExportResource(export)) {

                        long age = folder.getDateLastModified() < folder.getDateCreated() ? folder.getDateCreated()
                                : folder.getDateLastModified();
                        // export this folder only if age is above selected age
                        // default for selected age (if not set by user) is <code>long 0</code> (i.e. 1970)
                        if (age >= m_parameters.getContentAge()) {
                            // only export folder data to manifest.xml if it has changed
                            appendResourceToManifest(folder, false);
                        }

                        // export all sub-resources in this folder
                        addChildResources(getCms().getSitePath(folder));
                    }
                }
                // release folder memory
                subFolders.set(i, null);
            }
        } catch (CmsImportExportException e) {

            throw e;
        } catch (CmsException e) {

            CmsMessageContainer message = Messages.get()
                    .container(Messages.ERR_IMPORTEXPORT_ERROR_ADDING_CHILD_RESOURCES_1, folderName);
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), e);
            }

            throw new CmsImportExportException(message, e);
        }
    }

    /**
     * Adds all files in fileNames to the manifest.xml file.<p>
     * 
     * @param fileNames list of path Strings, e.g. <code>/folder/index.html</code>
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws IOException if a file could not be exported
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void addFiles(List<String> fileNames) throws CmsImportExportException, IOException, SAXException {

        if (fileNames != null) {
            for (int i = 0; i < fileNames.size(); i++) {
                String fileName = fileNames.get(i);

                try {
                    CmsFile file = getCms().readFile(fileName, CmsResourceFilter.IGNORE_EXPIRATION);
                    if (!file.getState().isDeleted() && !CmsWorkplace.isTemporaryFile(file)) {
                        if (checkExportResource(fileName)) {
                            if (m_parameters.isRecursive()) {
                                addParentFolders(fileName);
                            }
                            if (isInExportableProject(file)) {
                                exportFile(file);
                            }
                        }
                    }
                } catch (CmsImportExportException e) {

                    throw e;
                } catch (CmsException e) {
                    if (e instanceof CmsVfsException) { // file not found
                        CmsMessageContainer message = Messages.get()
                                .container(Messages.ERR_IMPORTEXPORT_ERROR_ADDING_FILE_1, fileName);
                        if (LOG.isDebugEnabled()) {
                            LOG.debug(message.key(), e);
                        }

                        throw new CmsImportExportException(message, e);
                    }
                }
            }
        }
    }

    /**
     * Adds the parent folders of the given resource to the config file, 
     * starting at the top, excluding the root folder.<p>
     * 
     * @param resourceName the name of a resource in the VFS
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void addParentFolders(String resourceName) throws CmsImportExportException, SAXException {

        try {
            // this is a resource in /system/ folder and option includeSystem is not true
            if (!checkExportResource(resourceName)) {
                return;
            }

            // Initialize the "previously added folder cache"
            if (m_superFolders == null) {
                m_superFolders = new ArrayList<String>();
            }
            List<String> superFolders = new ArrayList<String>();

            // Check, if the path is really a folder
            if (resourceName.lastIndexOf("/") != (resourceName.length() - 1)) {
                resourceName = resourceName.substring(0, resourceName.lastIndexOf("/") + 1);
            }
            while (resourceName.length() > "/".length()) {
                superFolders.add(resourceName);
                resourceName = resourceName.substring(0, resourceName.length() - 1);
                resourceName = resourceName.substring(0, resourceName.lastIndexOf("/") + 1);
            }
            for (int i = superFolders.size() - 1; i >= 0; i--) {
                String addFolder = superFolders.get(i);
                if (!m_superFolders.contains(addFolder)) {
                    // This super folder was NOT added previously. Add it now!
                    CmsFolder folder = getCms().readFolder(addFolder, CmsResourceFilter.IGNORE_EXPIRATION);
                    appendResourceToManifest(folder, false);
                    // Remember that this folder was added
                    m_superFolders.add(addFolder);
                }
            }
        } catch (CmsImportExportException e) {

            throw e;
        } catch (CmsException e) {

            CmsMessageContainer message = Messages.get()
                    .container(Messages.ERR_IMPORTEXPORT_ERROR_ADDING_PARENT_FOLDERS_1, resourceName);
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), e);
            }

            throw new CmsImportExportException(message, e);
        }
    }

    /**
     * Adds a property node to the manifest.xml.<p>
     * 
     * @param propertiesElement the parent element to append the node to
     * @param propertyName the name of the property
     * @param propertyValue the value of the property
     * @param shared if <code>true</code>, add a shared property attribute to the generated property node
     */
    protected void addPropertyNode(Element propertiesElement, String propertyName, String propertyValue,
            boolean shared) {

        if (propertyValue != null) {
            Element propertyElement = propertiesElement.addElement(CmsImportVersion7.N_PROPERTY);
            if (shared) {
                // add "type" attribute to the property node in case of a shared/resource property value
                propertyElement.addAttribute(CmsImportVersion7.A_TYPE,
                        CmsImportVersion7.PROPERTY_ATTRIB_TYPE_SHARED);
            }
            propertyElement.addElement(CmsImportVersion7.N_NAME).addText(propertyName);
            propertyElement.addElement(CmsImportVersion7.N_VALUE).addCDATA(propertyValue);
        }
    }

    /**
     * Adds a relation node to the <code>manifest.xml</code>.<p>
     * 
     * @param relationsElement the parent element to append the node to
     * @param structureId the structure id of the target relation
     * @param sitePath the site path of the target relation
     * @param relationType the type of the relation
     */
    protected void addRelationNode(Element relationsElement, String structureId, String sitePath,
            String relationType) {

        if ((structureId != null) && (sitePath != null) && (relationType != null)) {
            Element relationElement = relationsElement.addElement(CmsImportVersion7.N_RELATION);

            relationElement.addElement(CmsImportVersion7.N_ID).addText(structureId);
            relationElement.addElement(CmsImportVersion7.N_PATH).addText(sitePath);
            relationElement.addElement(CmsImportVersion7.N_TYPE).addText(relationType);
        }
    }

    /**
     * Writes the data for a resource (like access-rights) to the <code>manifest.xml</code> file.<p>
     * 
     * @param resource the resource to get the data from
     * @param source flag to show if the source information in the xml file must be written
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void appendResourceToManifest(CmsResource resource, boolean source)
            throws CmsImportExportException, SAXException {

        try {
            // only write <source> if resource is a file
            String fileName = trimResourceName(getCms().getSitePath(resource));
            if (fileName.startsWith("system/orgunits")) {
                // it is not allowed to export organizational unit resources
                // export the organizational units instead
                return;
            }

            // define the file node
            Element fileElement = m_resourceNode.addElement(CmsImportVersion7.N_FILE);

            if (resource.isFile()) {
                if (source) {
                    fileElement.addElement(CmsImportVersion7.N_SOURCE).addText(fileName);
                }
            } else {
                m_exportCount++;
                I_CmsReport report = getReport();
                // output something to the report for the folder
                report.print(org.opencms.report.Messages.get()
                        .container(org.opencms.report.Messages.RPT_SUCCESSION_1, String.valueOf(m_exportCount)),
                        I_CmsReport.FORMAT_NOTE);
                report.print(Messages.get().container(Messages.RPT_EXPORT_0), I_CmsReport.FORMAT_NOTE);
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_ARGUMENT_1,
                        getCms().getSitePath(resource)));
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_DOTS_0));
                report.println(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_OK_0),
                        I_CmsReport.FORMAT_OK);

                if (LOG.isInfoEnabled()) {
                    LOG.info(Messages.get().getBundle().key(Messages.LOG_EXPORTING_OK_2,
                            String.valueOf(m_exportCount), getCms().getSitePath(resource)));
                }
            }

            // <destination>
            fileElement.addElement(CmsImportVersion7.N_DESTINATION).addText(fileName);
            // <type>
            fileElement.addElement(CmsImportVersion7.N_TYPE)
                    .addText(OpenCms.getResourceManager().getResourceType(resource.getTypeId()).getTypeName());

            //  <uuidstructure>
            fileElement.addElement(CmsImportVersion7.N_UUIDSTRUCTURE).addText(resource.getStructureId().toString());
            if (resource.isFile()) {
                //  <uuidresource>
                fileElement.addElement(CmsImportVersion7.N_UUIDRESOURCE)
                        .addText(resource.getResourceId().toString());
            }

            // <datelastmodified>
            fileElement.addElement(CmsImportVersion7.N_DATELASTMODIFIED)
                    .addText(CmsDateUtil.getHeaderDate(resource.getDateLastModified()));
            // <userlastmodified>
            String userNameLastModified = null;
            try {
                userNameLastModified = getCms().readUser(resource.getUserLastModified()).getName();
            } catch (CmsException e) {
                userNameLastModified = OpenCms.getDefaultUsers().getUserAdmin();
            }
            fileElement.addElement(CmsImportVersion7.N_USERLASTMODIFIED).addText(userNameLastModified);
            // <datecreated>
            fileElement.addElement(CmsImportVersion7.N_DATECREATED)
                    .addText(CmsDateUtil.getHeaderDate(resource.getDateCreated()));
            // <usercreated>
            String userNameCreated = null;
            try {
                userNameCreated = getCms().readUser(resource.getUserCreated()).getName();
            } catch (CmsException e) {
                userNameCreated = OpenCms.getDefaultUsers().getUserAdmin();
            }
            fileElement.addElement(CmsImportVersion7.N_USERCREATED).addText(userNameCreated);
            // <release>
            if (resource.getDateReleased() != CmsResource.DATE_RELEASED_DEFAULT) {
                fileElement.addElement(CmsImportVersion7.N_DATERELEASED)
                        .addText(CmsDateUtil.getHeaderDate(resource.getDateReleased()));
            }
            // <expire>
            if (resource.getDateExpired() != CmsResource.DATE_EXPIRED_DEFAULT) {
                fileElement.addElement(CmsImportVersion7.N_DATEEXPIRED)
                        .addText(CmsDateUtil.getHeaderDate(resource.getDateExpired()));
            }
            // <flags>
            int resFlags = resource.getFlags();
            resFlags &= ~CmsResource.FLAG_LABELED;
            fileElement.addElement(CmsImportVersion7.N_FLAGS).addText(Integer.toString(resFlags));

            // write the properties to the manifest
            Element propertiesElement = fileElement.addElement(CmsImportVersion7.N_PROPERTIES);
            List<CmsProperty> properties = getCms().readPropertyObjects(getCms().getSitePath(resource), false);
            // sort the properties for a well defined output order
            Collections.sort(properties);
            for (int i = 0, n = properties.size(); i < n; i++) {
                CmsProperty property = properties.get(i);
                if (isIgnoredProperty(property)) {
                    continue;
                }
                addPropertyNode(propertiesElement, property.getName(), property.getStructureValue(), false);
                addPropertyNode(propertiesElement, property.getName(), property.getResourceValue(), true);
            }

            // Write the relations to the manifest
            List<CmsRelation> relations = getCms().getRelationsForResource(resource,
                    CmsRelationFilter.TARGETS.filterNotDefinedInContent());
            Element relationsElement = fileElement.addElement(CmsImportVersion7.N_RELATIONS);
            // iterate over the relations 
            for (CmsRelation relation : relations) {
                // relation may be broken already: 
                try {
                    CmsResource target = relation.getTarget(getCms(), CmsResourceFilter.ALL);
                    String structureId = target.getStructureId().toString();
                    String sitePath = getCms().getSitePath(target);
                    String relationType = relation.getType().getName();
                    addRelationNode(relationsElement, structureId, sitePath, relationType);
                } catch (CmsVfsResourceNotFoundException crnfe) {
                    // skip this relation: 
                    if (LOG.isWarnEnabled()) {
                        LOG.warn(Messages.get().getBundle().key(Messages.LOG_IMPORTEXPORT_WARN_DELETED_RELATIONS_2,
                                new String[] { relation.getTargetPath(), resource.getRootPath() }), crnfe);
                    }
                }
            }

            // append the nodes for access control entries
            Element acl = fileElement.addElement(CmsImportVersion7.N_ACCESSCONTROL_ENTRIES);

            // read the access control entries
            List<CmsAccessControlEntry> fileAcEntries = getCms()
                    .getAccessControlEntries(getCms().getSitePath(resource), false);
            Iterator<CmsAccessControlEntry> i = fileAcEntries.iterator();

            // create xml elements for each access control entry
            while (i.hasNext()) {
                CmsAccessControlEntry ace = i.next();
                Element a = acl.addElement(CmsImportVersion7.N_ACCESSCONTROL_ENTRY);

                // now check if the principal is a group or a user
                int flags = ace.getFlags();
                String acePrincipalName = "";
                CmsUUID acePrincipal = ace.getPrincipal();
                if ((flags & CmsAccessControlEntry.ACCESS_FLAGS_ALLOTHERS) > 0) {
                    acePrincipalName = CmsAccessControlEntry.PRINCIPAL_ALL_OTHERS_NAME;
                } else if ((flags & CmsAccessControlEntry.ACCESS_FLAGS_OVERWRITE_ALL) > 0) {
                    acePrincipalName = CmsAccessControlEntry.PRINCIPAL_OVERWRITE_ALL_NAME;
                } else if ((flags & CmsAccessControlEntry.ACCESS_FLAGS_GROUP) > 0) {
                    // the principal is a group
                    acePrincipalName = getCms().readGroup(acePrincipal).getPrefixedName();
                } else if ((flags & CmsAccessControlEntry.ACCESS_FLAGS_USER) > 0) {
                    // the principal is a user
                    acePrincipalName = getCms().readUser(acePrincipal).getPrefixedName();
                } else {
                    // the principal is a role
                    acePrincipalName = CmsRole.PRINCIPAL_ROLE + "." + CmsRole.valueOfId(acePrincipal).getRoleName();
                }

                a.addElement(CmsImportVersion7.N_ACCESSCONTROL_PRINCIPAL).addText(acePrincipalName);
                a.addElement(CmsImportVersion7.N_FLAGS).addText(Integer.toString(flags));

                Element b = a.addElement(CmsImportVersion7.N_ACCESSCONTROL_PERMISSIONSET);
                b.addElement(CmsImportVersion7.N_ACCESSCONTROL_ALLOWEDPERMISSIONS)
                        .addText(Integer.toString(ace.getAllowedPermissions()));
                b.addElement(CmsImportVersion7.N_ACCESSCONTROL_DENIEDPERMISSIONS)
                        .addText(Integer.toString(ace.getDeniedPermissions()));
            }

            // write the XML
            digestElement(m_resourceNode, fileElement);
        } catch (CmsImportExportException e) {

            throw e;
        } catch (CmsException e) {

            CmsMessageContainer message = Messages.get().container(
                    Messages.ERR_IMPORTEXPORT_ERROR_APPENDING_RESOURCE_TO_MANIFEST_1, resource.getRootPath());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), e);
            }

            throw new CmsImportExportException(message, e);
        }
    }

    /**
     * Returns true if the checked resource name can be exported depending on the include settings.<p>
     * 
     * @param resourcename the absolute path of the resource
     * @return true if the checked resource name can be exported depending on the include settings
     */
    protected boolean checkExportResource(String resourcename) {

        return (// other folder than "/system/" will be exported
        !resourcename.startsWith(CmsWorkplace.VFS_PATH_SYSTEM) // OR always export "/system/"
                || resourcename.equalsIgnoreCase(CmsWorkplace.VFS_PATH_SYSTEM) // OR always export "/system/galleries/"
                || resourcename.startsWith(CmsWorkplace.VFS_PATH_GALLERIES) // OR option "include system folder" selected
                || (m_parameters.isIncludeSystemFolder() // AND export folder is a system folder
                        && resourcename.startsWith(CmsWorkplace.VFS_PATH_SYSTEM)));
    }

    /**
     * Closes the export ZIP file and saves the XML document for the manifest.<p>
     * 
     * @param exportNode the export root node
     * 
     * @throws SAXException if something goes wrong processing the manifest.xml
     * @throws IOException if something goes wrong while closing the export file
     */
    protected void closeExportFile(Element exportNode) throws IOException, SAXException {

        // close the <export> Tag
        getSaxWriter().writeClose(exportNode);

        // close the XML document 
        CmsXmlSaxWriter xmlSaxWriter = (CmsXmlSaxWriter) getSaxWriter().getContentHandler();

        // write the manifest file
        m_exportWriter.writeManifest(xmlSaxWriter);
    }

    /**
     * Writes the output element to the XML output writer and detaches it 
     * from it's parent element.<p> 
     * 
     * @param parent the parent element
     * @param output the output element 
     * 
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void digestElement(Element parent, Element output) throws SAXException {

        m_saxWriter.write(output);
        parent.remove(output);
    }

    /**
     * Exports all resources and possible sub-folders form the provided list of resources.
     * 
     * @param parent the parent node to add the resources to
     * @param resourcesToExport the list of resources to export
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     * @throws IOException if not all resources could be appended to the ZIP archive
     */
    protected void exportAllResources(Element parent, List<String> resourcesToExport)
            throws CmsImportExportException, IOException, SAXException {

        // export all the resources
        String resourceNodeName = getResourceNodeName();
        m_resourceNode = parent.addElement(resourceNodeName);
        getSaxWriter().writeOpen(m_resourceNode);

        if (m_parameters.isRecursive()) {
            // remove the possible redundancies in the list of resources
            resourcesToExport = CmsFileUtil.removeRedundancies(resourcesToExport);
        }

        // distinguish folder and file names   
        List<String> folderNames = new ArrayList<String>();
        List<String> fileNames = new ArrayList<String>();
        Iterator<String> it = resourcesToExport.iterator();
        while (it.hasNext()) {
            String resource = it.next();
            if (CmsResource.isFolder(resource)) {
                folderNames.add(resource);
            } else {
                fileNames.add(resource);
            }
        }

        m_exportedResources = new HashSet<CmsUUID>();

        // export the folders
        for (int i = 0; i < folderNames.size(); i++) {
            String path = folderNames.get(i);
            if (m_parameters.isRecursive()) {
                // first add super folders to the xml-config file
                addParentFolders(path);
                addChildResources(path);
            } else {
                CmsFolder folder;
                try {
                    folder = getCms().readFolder(path, CmsResourceFilter.IGNORE_EXPIRATION);
                } catch (CmsException e) {
                    CmsMessageContainer message = Messages.get()
                            .container(Messages.ERR_IMPORTEXPORT_ERROR_ADDING_PARENT_FOLDERS_1, path);
                    if (LOG.isDebugEnabled()) {
                        LOG.debug(message.key(), e);
                    }
                    throw new CmsImportExportException(message, e);
                }
                CmsResourceState state = folder.getState();
                long age = folder.getDateLastModified() < folder.getDateCreated() ? folder.getDateCreated()
                        : folder.getDateLastModified();

                if (getCms().getRequestContext().getCurrentProject().isOnlineProject()
                        || (m_parameters.isIncludeUnchangedResources()) || state.isNew() || state.isChanged()) {
                    if (!state.isDeleted() && (age >= m_parameters.getContentAge())) {
                        // check if this is a system-folder and if it should be included.
                        String export = getCms().getSitePath(folder);
                        if (checkExportResource(export)) {
                            appendResourceToManifest(folder, false);
                        }
                    }
                }
            }
        }
        // export the files
        addFiles(fileNames);

        // write the XML
        getSaxWriter().writeClose(m_resourceNode);
        parent.remove(m_resourceNode);
        m_resourceNode = null;
    }

    /**
     * Exports one single file with all its data and content.<p>
     *
     * @param file the file to be exported
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     * @throws IOException if the ZIP entry for the file could be appended to the ZIP archive
     */
    protected void exportFile(CmsFile file) throws CmsImportExportException, SAXException, IOException {

        String source = trimResourceName(getCms().getSitePath(file));
        I_CmsReport report = getReport();
        m_exportCount++;
        report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_SUCCESSION_1,
                String.valueOf(m_exportCount)), I_CmsReport.FORMAT_NOTE);
        report.print(Messages.get().container(Messages.RPT_EXPORT_0), I_CmsReport.FORMAT_NOTE);
        report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_ARGUMENT_1,
                getCms().getSitePath(file)));
        report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_DOTS_0));

        // store content in zip-file
        // check if the content of this resource was not already exported
        if (!m_exportedResources.contains(file.getResourceId())) {
            // write the file using the export writer 
            m_exportWriter.writeFile(file, source);
            // add the resource id to the storage to mark that this resource was already exported
            m_exportedResources.add(file.getResourceId());
            // create the manifest-entries
            appendResourceToManifest(file, true);
        } else {
            // only create the manifest-entries
            appendResourceToManifest(file, false);
        }

        if (LOG.isInfoEnabled()) {
            LOG.info(Messages.get().getBundle().key(Messages.LOG_EXPORTING_OK_2, String.valueOf(m_exportCount),
                    source));
        }
        report.println(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_OK_0),
                I_CmsReport.FORMAT_OK);
    }

    /**
     * Exports one single group with all it's data.<p>
     *
     * @param parent the parent node to add the groups to
     * @param group the group to be exported
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportGroup(Element parent, CmsGroup group) throws CmsImportExportException, SAXException {

        try {
            String parentgroup;
            if ((group.getParentId() == null) || group.getParentId().isNullUUID()) {
                parentgroup = "";
            } else {
                parentgroup = getCms().getParent(group.getName()).getName();
            }

            Element e = parent.addElement(CmsImportVersion7.N_GROUP);
            e.addElement(CmsImportVersion7.N_NAME).addText(group.getSimpleName());
            e.addElement(CmsImportVersion7.N_DESCRIPTION).addCDATA(group.getDescription());
            e.addElement(CmsImportVersion7.N_FLAGS).addText(Integer.toString(group.getFlags()));
            e.addElement(CmsImportVersion7.N_PARENTGROUP).addText(parentgroup);

            // write the XML
            digestElement(parent, e);
        } catch (CmsException e) {
            CmsMessageContainer message = org.opencms.db.Messages.get()
                    .container(org.opencms.db.Messages.ERR_GET_PARENT_GROUP_1, group.getName());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), e);
            }

            throw new CmsImportExportException(message, e);
        }
    }

    /**
     * Exports all groups of the given organizational unit.<p>
     *
     * @param parent the parent node to add the groups to
     * @param orgunit the organizational unit to write the groups for
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportGroups(Element parent, CmsOrganizationalUnit orgunit)
            throws CmsImportExportException, SAXException {

        try {
            I_CmsReport report = getReport();
            List<CmsGroup> allGroups = OpenCms.getOrgUnitManager().getGroups(getCms(), orgunit.getName(), false);
            for (int i = 0, l = allGroups.size(); i < l; i++) {
                CmsGroup group = allGroups.get(i);
                report.print(
                        org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_SUCCESSION_2,
                                String.valueOf(i + 1), String.valueOf(l)),
                        I_CmsReport.FORMAT_NOTE);
                report.print(Messages.get().container(Messages.RPT_EXPORT_GROUP_0), I_CmsReport.FORMAT_NOTE);
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_ARGUMENT_1,
                        group.getName()));
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_DOTS_0));
                exportGroup(parent, group);
                report.println(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_OK_0),
                        I_CmsReport.FORMAT_OK);
            }
        } catch (CmsImportExportException e) {
            throw e;
        } catch (CmsException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug(e.getLocalizedMessage(), e);
            }
            throw new CmsImportExportException(e.getMessageContainer(), e);
        }
    }

    /**
     * Exports one single organizational unit with all it's data.<p>
     *
     * @param parent the parent node to add the groups to
     * @param orgunit the group to be exported
     * 
     * @throws SAXException if something goes wrong processing the manifest.xml
     * @throws CmsException if something goes wrong reading the data to export
     */
    protected void exportOrgUnit(Element parent, CmsOrganizationalUnit orgunit) throws SAXException, CmsException {

        Element orgunitElement = parent.addElement(CmsImportVersion7.N_ORGUNIT);
        getSaxWriter().writeOpen(orgunitElement);

        Element name = orgunitElement.addElement(CmsImportVersion7.N_NAME).addText(orgunit.getName());
        digestElement(orgunitElement, name);

        Element description = orgunitElement.addElement(CmsImportVersion7.N_DESCRIPTION)
                .addCDATA(orgunit.getDescription());
        digestElement(orgunitElement, description);

        Element flags = orgunitElement.addElement(CmsImportVersion7.N_FLAGS)
                .addText(Integer.toString(orgunit.getFlags()));
        digestElement(orgunitElement, flags);

        Element resources = orgunitElement.addElement(CmsImportVersion7.N_RESOURCES);
        Iterator<CmsResource> it = OpenCms.getOrgUnitManager()
                .getResourcesForOrganizationalUnit(getCms(), orgunit.getName()).iterator();
        while (it.hasNext()) {
            CmsResource resource = it.next();
            resources.addElement(CmsImportVersion7.N_RESOURCE).addText(resource.getRootPath());
        }
        digestElement(orgunitElement, resources);
        getReport().println(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_OK_0),
                I_CmsReport.FORMAT_OK);

        Element groupsElement = parent.addElement(CmsImportVersion7.N_GROUPS);
        getSaxWriter().writeOpen(groupsElement);
        exportGroups(groupsElement, orgunit);
        getSaxWriter().writeClose(groupsElement);

        Element usersElement = parent.addElement(CmsImportVersion7.N_USERS);
        getSaxWriter().writeOpen(usersElement);
        exportUsers(usersElement, orgunit);
        getSaxWriter().writeClose(usersElement);

        getSaxWriter().writeClose(orgunitElement);
    }

    /**
     * Exports all organizational units with all data.<p>
     *
     * @param parent the parent node to add the organizational units to
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportOrgUnits(Element parent) throws CmsImportExportException, SAXException {

        try {
            Element orgunitsElement = parent.addElement(CmsImportVersion7.N_ORGUNITS);
            getSaxWriter().writeOpen(orgunitsElement);

            I_CmsReport report = getReport();
            List<CmsOrganizationalUnit> allOUs = new ArrayList<CmsOrganizationalUnit>();
            allOUs.add(OpenCms.getOrgUnitManager().readOrganizationalUnit(getCms(), ""));
            allOUs.addAll(OpenCms.getOrgUnitManager().getOrganizationalUnits(getCms(), "", true));
            for (int i = 0; i < allOUs.size(); i++) {
                CmsOrganizationalUnit ou = allOUs.get(i);
                report.print(
                        org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_SUCCESSION_2,
                                String.valueOf(i + 1), String.valueOf(allOUs.size())),
                        I_CmsReport.FORMAT_NOTE);
                report.print(Messages.get().container(Messages.RPT_EXPORT_ORGUNIT_0), I_CmsReport.FORMAT_NOTE);
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_ARGUMENT_1,
                        ou.getName()));
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_DOTS_0));

                exportOrgUnit(orgunitsElement, ou);
            }
            getSaxWriter().writeClose(orgunitsElement);
        } catch (CmsImportExportException e) {
            throw e;
        } catch (CmsException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug(e.getLocalizedMessage(), e);
            }
            throw new CmsImportExportException(e.getMessageContainer(), e);
        }
    }

    /**
     * Exports one single project with all it's data.<p>
     *
     * @param parent the parent node to add the project to
     * @param project the project to be exported
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportProject(Element parent, CmsProject project) throws CmsImportExportException, SAXException {

        String users;
        try {
            users = getCms().readGroup(project.getGroupId()).getName();
        } catch (CmsException e) {
            CmsMessageContainer message = org.opencms.db.Messages.get()
                    .container(org.opencms.db.Messages.ERR_READ_GROUP_FOR_ID_1, project.getGroupId());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), e);
            }

            throw new CmsImportExportException(message, e);
        }
        String managers;
        try {
            managers = getCms().readGroup(project.getManagerGroupId()).getName();
        } catch (CmsException e) {
            CmsMessageContainer message = org.opencms.db.Messages.get()
                    .container(org.opencms.db.Messages.ERR_READ_GROUP_FOR_ID_1, project.getManagerGroupId());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), e);
            }

            throw new CmsImportExportException(message, e);
        }

        Element e = parent.addElement(CmsImportVersion7.N_PROJECT);
        e.addElement(CmsImportVersion7.N_NAME).addText(project.getSimpleName());
        e.addElement(CmsImportVersion7.N_DESCRIPTION).addCDATA(project.getDescription());
        e.addElement(CmsImportVersion7.N_USERSGROUP).addText(users);
        e.addElement(CmsImportVersion7.N_MANAGERSGROUP).addText(managers);

        Element resources = e.addElement(CmsImportVersion7.N_RESOURCES);
        try {
            Iterator<String> it = getCms().readProjectResources(project).iterator();
            while (it.hasNext()) {
                String resName = it.next();
                resources.addElement(CmsImportVersion7.N_RESOURCE).addText(resName);
            }
        } catch (CmsException exc) {
            CmsMessageContainer message = org.opencms.db.Messages.get().container(
                    org.opencms.db.Messages.ERR_READ_PROJECT_RESOURCES_2, project.getName(), project.getUuid());
            if (LOG.isDebugEnabled()) {
                LOG.debug(message.key(), exc);
            }

            throw new CmsImportExportException(message, exc);
        }
        // write the XML
        digestElement(parent, e);
    }

    /**
     * Exports all projects with all data.<p>
     *
     * @param parent the parent node to add the projects to
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportProjects(Element parent) throws CmsImportExportException, SAXException {

        try {
            I_CmsReport report = getReport();
            List<CmsProject> allProjects = OpenCms.getOrgUnitManager().getAllManageableProjects(getCms(), "", true);
            for (int i = 0; i < allProjects.size(); i++) {
                CmsProject project = allProjects.get(i);
                report.print(
                        org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_SUCCESSION_2,
                                String.valueOf(i + 1), String.valueOf(allProjects.size())),
                        I_CmsReport.FORMAT_NOTE);
                report.print(Messages.get().container(Messages.RPT_EXPORT_PROJECT_0), I_CmsReport.FORMAT_NOTE);
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_ARGUMENT_1,
                        project.getName()));
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_DOTS_0));

                exportProject(parent, project);

                report.println(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_OK_0),
                        I_CmsReport.FORMAT_OK);
            }
        } catch (CmsImportExportException e) {
            throw e;
        } catch (CmsException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug(e.getLocalizedMessage(), e);
            }
            throw new CmsImportExportException(e.getMessageContainer(), e);
        }
    }

    /**
     * Exports one single user with all its data.<p>
     * 
     * @param parent the parent node to add the users to
     * @param user the user to be exported
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportUser(Element parent, CmsUser user) throws CmsImportExportException, SAXException {

        try {
            // add user node to the manifest.xml
            Element e = parent.addElement(CmsImportVersion7.N_USER);
            e.addElement(CmsImportVersion7.N_NAME).addText(user.getSimpleName());
            // encode the password, using a base 64 decoder
            String passwd = new String(Base64.encodeBase64(user.getPassword().getBytes()));
            e.addElement(CmsImportVersion7.N_PASSWORD).addCDATA(passwd);
            e.addElement(CmsImportVersion7.N_FIRSTNAME).addText(user.getFirstname());
            e.addElement(CmsImportVersion7.N_LASTNAME).addText(user.getLastname());
            e.addElement(CmsImportVersion7.N_EMAIL).addText(user.getEmail());
            e.addElement(CmsImportVersion7.N_FLAGS).addText(Integer.toString(user.getFlags()));
            e.addElement(CmsImportVersion7.N_DATECREATED).addText(Long.toString(user.getDateCreated()));

            Element userInfoNode = e.addElement(CmsImportVersion7.N_USERINFO);
            List<String> keys = new ArrayList<String>(user.getAdditionalInfo().keySet());
            Collections.sort(keys);
            Iterator<String> itInfoKeys = keys.iterator();
            while (itInfoKeys.hasNext()) {
                String key = itInfoKeys.next();
                if (key == null) {
                    continue;
                }
                Object value = user.getAdditionalInfo(key);
                if (value == null) {
                    continue;
                }
                Element entryNode = userInfoNode.addElement(CmsImportVersion7.N_USERINFO_ENTRY);
                entryNode.addAttribute(CmsImportVersion7.A_NAME, key);
                entryNode.addAttribute(CmsImportVersion7.A_TYPE, value.getClass().getName());
                try {
                    // serialize the user info and write it into a file
                    entryNode.addCDATA(CmsDataTypeUtil.dataExport(value));
                } catch (IOException ioe) {
                    getReport().println(ioe);
                    if (LOG.isErrorEnabled()) {
                        LOG.error(Messages.get().getBundle().key(Messages.ERR_IMPORTEXPORT_ERROR_EXPORTING_USER_1,
                                user.getName()), ioe);
                    }
                }
            }

            // append node for roles of user
            Element userRoles = e.addElement(CmsImportVersion7.N_USERROLES);
            List<CmsRole> roles = OpenCms.getRoleManager().getRolesOfUser(getCms(), user.getName(), "", true, true,
                    true);
            for (int i = 0; i < roles.size(); i++) {
                String roleName = roles.get(i).getFqn();
                userRoles.addElement(CmsImportVersion7.N_USERROLE).addText(roleName);
            }
            // append the node for groups of user
            Element userGroups = e.addElement(CmsImportVersion7.N_USERGROUPS);
            List<CmsGroup> groups = getCms().getGroupsOfUser(user.getName(), true, true);
            for (int i = 0; i < groups.size(); i++) {
                String groupName = groups.get(i).getName();
                userGroups.addElement(CmsImportVersion7.N_USERGROUP).addText(groupName);
            }
            // write the XML
            digestElement(parent, e);
        } catch (CmsException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug(e.getLocalizedMessage(), e);
            }
            throw new CmsImportExportException(e.getMessageContainer(), e);
        }
    }

    /**
     * Exports all users of the given organizational unit.<p>
     *
     * @param parent the parent node to add the users to
     * @param orgunit the organizational unit to write the groups for
     * 
     * @throws CmsImportExportException if something goes wrong
     * @throws SAXException if something goes wrong processing the manifest.xml
     */
    protected void exportUsers(Element parent, CmsOrganizationalUnit orgunit)
            throws CmsImportExportException, SAXException {

        try {
            I_CmsReport report = getReport();
            List<CmsUser> allUsers = OpenCms.getOrgUnitManager().getUsers(getCms(), orgunit.getName(), false);
            for (int i = 0, l = allUsers.size(); i < l; i++) {
                CmsUser user = allUsers.get(i);
                report.print(
                        org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_SUCCESSION_2,
                                String.valueOf(i + 1), String.valueOf(l)),
                        I_CmsReport.FORMAT_NOTE);
                report.print(Messages.get().container(Messages.RPT_EXPORT_USER_0), I_CmsReport.FORMAT_NOTE);
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_ARGUMENT_1,
                        user.getName()));
                report.print(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_DOTS_0));
                exportUser(parent, user);
                report.println(org.opencms.report.Messages.get().container(org.opencms.report.Messages.RPT_OK_0),
                        I_CmsReport.FORMAT_OK);
            }
        } catch (CmsImportExportException e) {
            throw e;
        } catch (CmsException e) {
            if (LOG.isDebugEnabled()) {
                LOG.debug(e.getLocalizedMessage(), e);
            }
            throw new CmsImportExportException(e.getMessageContainer(), e);
        }
    }

    /**
     * Returns the OpenCms context object this export was initialized with.<p>
     * 
     * @return the OpenCms context object this export was initialized with
     */
    protected CmsObject getCms() {

        return m_cms;
    }

    /**
     * Returns the name of the export file.<p>
     * 
     * @return the name of the export file
     */
    protected String getExportFileName() {

        return m_parameters.getPath();
    }

    /**
     * Returns the name of the main export node.<p>
     * 
     * @return the name of the main export node
     */
    protected String getExportNodeName() {

        return CmsImportExportManager.N_EXPORT;
    }

    /**
     * Returns the report to write progress messages to.<p>
     * 
     * @return the report to write progress messages to
     */
    protected I_CmsReport getReport() {

        return m_report;
    }

    /**
     * Returns the name for the main resource node.<p>
     * 
     * @return the name for the main resource node
     */
    protected String getResourceNodeName() {

        return "files";
    }

    /**
     * Returns the SAX based xml writer to write the XML output to.<p>
     * 
     * @return the SAX based xml writer to write the XML output to
     */
    protected SAXWriter getSaxWriter() {

        return m_saxWriter;
    }

    /**
     * Checks if a property should be written to the export or not.<p>
     * 
     * @param property the property to check
     * 
     * @return if true, the property is to be ignored, otherwise it should be exported
     */
    protected boolean isIgnoredProperty(CmsProperty property) {

        if (property == null) {
            return true;
        }
        // default implementation is to export all properties not null
        return false;
    }

    /**
     * Checks if a resource is belongs to the correct project for exporting.<p>
     * 
     * @param res the resource to check
     * 
     * @return <code>true</code>, if the resource can be exported, false otherwise
     */
    protected boolean isInExportableProject(CmsResource res) {

        boolean retValue = true;
        // the "only modified in current project flag" is checked
        if (m_parameters.isInProject()) {
            // resource state is new or changed
            if ((res.getState() == CmsResource.STATE_CHANGED) || (res.getState() == CmsResource.STATE_NEW)) {
                // the resource belongs not to the current project, so it must not be exported    
                if (!res.getProjectLastModified()
                        .equals(getCms().getRequestContext().getCurrentProject().getUuid())) {
                    retValue = false;
                }
            } else {
                // state is unchanged, so do not export it
                retValue = false;
            }
        }
        return retValue;
    }

    /**
     * Opens the export ZIP file and initializes the internal XML document for the manifest.<p>
     * 
     * @return the node in the XML document where all files are appended to
     * 
     * @throws SAXException if something goes wrong processing the manifest.xml
     * @throws IOException if something goes wrong while closing the export file
     */
    protected Element openExportFile() throws IOException, SAXException {

        // create the export writer
        m_exportWriter = new CmsExportHelper(getExportFileName(), m_parameters.isExportAsFiles(),
                m_parameters.isXmlValidation());
        // initialize the dom4j writer object as member variable
        setSaxWriter(m_exportWriter.getSaxWriter());

        // the node in the XML document where the file entries are appended to        
        String exportNodeName = getExportNodeName();
        // the XML document to write the XMl to
        Document doc = DocumentHelper.createDocument();
        // add main export node to XML document
        Element exportNode = doc.addElement(exportNodeName);
        getSaxWriter().writeOpen(exportNode);

        // add the info element. it contains all infos for this export
        Element info = exportNode.addElement(CmsImportExportManager.N_INFO);
        info.addElement(CmsImportExportManager.N_CREATOR)
                .addText(getCms().getRequestContext().getCurrentUser().getName());
        info.addElement(CmsImportExportManager.N_OC_VERSION).addText(OpenCms.getSystemInfo().getVersionNumber());
        info.addElement(CmsImportExportManager.N_DATE)
                .addText(CmsDateUtil.getHeaderDate(System.currentTimeMillis()));
        info.addElement(CmsImportExportManager.N_INFO_PROJECT)
                .addText(getCms().getRequestContext().getCurrentProject().getName());
        info.addElement(CmsImportExportManager.N_VERSION).addText(CmsImportExportManager.EXPORT_VERSION);

        // write the XML
        digestElement(exportNode, info);

        return exportNode;
    }

    /**
     * Sets the SAX based XML writer to write the XML output to.<p>
     * 
     * @param saxWriter the SAX based XML writer to write the XML output to
     */
    protected void setSaxWriter(SAXWriter saxWriter) {

        m_saxWriter = saxWriter;
    }

    /**
     * Cuts leading and trailing '/' from the given resource name.<p>
     * 
     * @param resourceName the absolute path of a resource
     * 
     * @return the trimmed resource name
     */
    protected String trimResourceName(String resourceName) {

        if (resourceName.startsWith("/")) {
            resourceName = resourceName.substring(1);
        }
        if (resourceName.endsWith("/")) {
            resourceName = resourceName.substring(0, resourceName.length() - 1);
        }
        return resourceName;
    }
}