source: ComponentRegistry/trunk/ComponentRegistry/src/main/java/clarin/cmdi/componentregistry/impl/database/ComponentRegistryDbImpl.java @ 2067

package clarin.cmdi.componentregistry.impl.database;

import clarin.cmdi.componentregistry.CMDComponentSpecExpander;
import clarin.cmdi.componentregistry.ComponentRegistry;
import clarin.cmdi.componentregistry.ComponentRegistryException;
import clarin.cmdi.componentregistry.ComponentStatus;
import clarin.cmdi.componentregistry.Configuration;
import clarin.cmdi.componentregistry.DeleteFailedException;
import clarin.cmdi.componentregistry.MDMarshaller;
import clarin.cmdi.componentregistry.Owner;
import clarin.cmdi.componentregistry.OwnerGroup;
import clarin.cmdi.componentregistry.OwnerUser;
import clarin.cmdi.componentregistry.UserUnauthorizedException;
import clarin.cmdi.componentregistry.components.CMDComponentSpec;
import clarin.cmdi.componentregistry.impl.ComponentRegistryImplBase;
import clarin.cmdi.componentregistry.model.AbstractDescription;
import clarin.cmdi.componentregistry.model.Comment;
import clarin.cmdi.componentregistry.model.ComponentDescription;
import clarin.cmdi.componentregistry.model.ProfileDescription;
import clarin.cmdi.componentregistry.model.RegistryUser;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.security.Principal;
import java.text.ParseException;
import java.util.Calendar;
import java.util.Collection;
import java.util.Collections;
import java.util.Date;
import java.util.List;
import javax.xml.bind.JAXBException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Qualifier;
import org.springframework.dao.DataAccessException;

/**
 * Implementation of ComponentRegistry that uses Database Acces Objects for
 * accessing the registry (ergo: a database implementation)
 *
 * @author Twan Goosen <twan.goosen@mpi.nl>
 */
public class ComponentRegistryDbImpl extends ComponentRegistryImplBase implements ComponentRegistry {

    private final static Logger LOG = LoggerFactory.getLogger(ComponentRegistryDbImpl.class);
    private Owner owner;
    private ComponentStatus status;
    @Autowired
    private Configuration configuration;
    @Autowired
    @Qualifier("componentsCache")
    private CMDComponentSpecCache componentsCache;
    @Autowired
    @Qualifier("profilesCache")
    private CMDComponentSpecCache profilesCache;
    // DAO's
    @Autowired
    private ProfileDescriptionDao profileDescriptionDao;
    @Autowired
    private ComponentDescriptionDao componentDescriptionDao;
    @Autowired
    private UserDao userDao;
    @Autowired
    private CommentsDao commentsDao;

    /**
     * Default constructor, to use this as a (spring) bean. The public registry by default.
     * Use setStatus() and setOwner() to make it another kind of registry.
     *
     * @see setUser
     */
    public ComponentRegistryDbImpl() {
        this.status = ComponentStatus.PUBLIC;
    }

    /**
     * Creates a new ComponentRegistry (either public or not) for the provided
     * user. Only use for test and/or make sure to inject all dao's and other services
     *
     * @param userId
     * User id of the user to create registry for. Pass null for
     * public
     */
    public ComponentRegistryDbImpl(ComponentStatus status, Owner owner) {
        this.status = status;
        this.owner = owner;
    }

    @Override
    public List<ProfileDescription> getProfileDescriptions() throws ComponentRegistryException {
        try {
            switch (status) {
                // TODO: support other status types
                case DEVELOPMENT:
                    if (owner == null) {
                        throw new ComponentRegistryException("Development workspace without owner!");
                    }
                    // TODO: Support group space
                    return profileDescriptionDao.getUserspaceDescriptions(owner.getId());
                case PUBLIC:
                    return profileDescriptionDao.getPublicProfileDescriptions();
                default:
                    throw new ComponentRegistryException("Unsupported status type" + status);
            }
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get profile descriptions", ex);
        }
    }

    @Override
    public ProfileDescription getProfileDescription(String id) throws ComponentRegistryException {
        try {
            return profileDescriptionDao.getByCmdId(id, getUserId());
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get profile description", ex);
        }
    }

    @Override
    public List<ComponentDescription> getComponentDescriptions() throws ComponentRegistryException {
        try {
            if (isPublic()) {
                return componentDescriptionDao.getPublicComponentDescriptions();
            } else {
                return componentDescriptionDao.getUserspaceDescriptions(getUserId());
            }
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get component descriptions", ex);
        }
    }

    @Override
    public ComponentDescription getComponentDescription(String id) throws ComponentRegistryException {
        try {
            return componentDescriptionDao.getByCmdId(id, getUserId());
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get component description", ex);
        }
    }

    @Override
    public List<Comment> getCommentsInProfile(String profileId, Principal principal) throws ComponentRegistryException {
        try {
            if (profileDescriptionDao.isInRegistry(profileId, getUserId())) {
                final List<Comment> commentsFromProfile = commentsDao.getCommentsFromProfile(profileId);
                setCanDeleteInComments(commentsFromProfile, principal);
                return commentsFromProfile;
            } else {
                // Profile does not exist (at least not in this registry)
                throw new ComponentRegistryException("Profile " + profileId + " does not exist in specified registry");
            }
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get list of comments from profile", ex);
        }
    }

    @Override
    public Comment getSpecifiedCommentInProfile(String profileId, String commentId, Principal principal) throws ComponentRegistryException {
        try {
            Comment comment = commentsDao.getSpecifiedCommentFromProfile(commentId);
            if (comment != null
                    && profileId.equals(comment.getProfileDescriptionId())
                    && profileDescriptionDao.isInRegistry(comment.getProfileDescriptionId(), getUserId())) {
                setCanDeleteInComments(Collections.singleton(comment), principal);
                return comment;
            } else {
                // Comment exists in DB, but profile is not in this registry
                throw new ComponentRegistryException("Comment " + commentId + " cannot be found in specified registry");
            }
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get comment from profile", ex);
        }
    }

    @Override
    public List<Comment> getCommentsInComponent(String componentId, Principal principal) throws ComponentRegistryException {
        try {
            if (componentDescriptionDao.isInRegistry(componentId, getUserId())) {
                final List<Comment> commentsFromComponent = commentsDao.getCommentsFromComponent(componentId);
                setCanDeleteInComments(commentsFromComponent, principal);
                return commentsFromComponent;
            } else {
                // Component does not exist (at least not in this registry)
                throw new ComponentRegistryException("Component " + componentId + " does not exist in specified registry");
            }
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get list of comments from component", ex);
        }
    }

    @Override
    public Comment getSpecifiedCommentInComponent(String componentId, String commentId, Principal principal) throws ComponentRegistryException {
        try {
            Comment comment = commentsDao.getSpecifiedCommentFromComponent(commentId);
            if (comment != null
                    && componentId.equals(comment.getComponentDescriptionId())
                    && componentDescriptionDao.isInRegistry(comment.getComponentDescriptionId(), getUserId())) {
                setCanDeleteInComments(Collections.singleton(comment), principal);
                return comment;
            } else {
                // Comment does not exists in DB or component is not in this registry
                throw new ComponentRegistryException("Comment " + commentId + " cannot be found in specified registry for specified component");
            }
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get comment from component", ex);
        }
    }

    /**
     * Sets the {@link Comment#setCanDelete(boolean) canDelete} property on all comments in the provided collection for the perspective of
     * the specified principal.
     * Comment owners (determined by {@link Comment#getUserId() }) and admins can delete, others cannot.
     *
     * @param comments comments to configure
     * @param principal user to configure for
     * @see Comment#isCanDelete()
     */
    private void setCanDeleteInComments(Collection<Comment> comments, Principal principal) {
        if (principal != null && principal.getName() != null) {
            final RegistryUser registryUser = userDao.getByPrincipalName(principal.getName());
            final String registryUserId = registryUser == null ? null : registryUser.getId().toString();
            final boolean isAdmin = registryUser != null && configuration.isAdminUser(principal);
            for (Comment comment : comments) {
                comment.setCanDelete(isAdmin || comment.getUserId().equals(registryUserId));
            }
        }
    }

    @Override
    public CMDComponentSpec getMDProfile(String id) throws ComponentRegistryException {
        if (inWorkspace(profileDescriptionDao, id)) {
            CMDComponentSpec result = profilesCache.get(id);
            if (result == null && !profilesCache.containsKey(id)) {
                result = getUncachedMDProfile(id);
                profilesCache.put(id, result);
            }
            return result;
        } else {
            // May exist, but not in this workspace
            LOG.warn("Could not find profile '{}' in registry '{}'", new Object[]{id, this.toString()});
            return null;
        }
    }

    public CMDComponentSpec getUncachedMDProfile(String id) throws ComponentRegistryException {
        try {
            return getUncachedMDComponent(id, profileDescriptionDao);
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get profile", ex);
        }
    }

    @Override
    public CMDComponentSpec getMDComponent(String id) throws ComponentRegistryException {
        if (inWorkspace(componentDescriptionDao, id)) {
            CMDComponentSpec result = componentsCache.get(id);
            if (result == null && !componentsCache.containsKey(id)) {
                result = getUncachedMDComponent(id);
                componentsCache.put(id, result);
            }
            return result;
        } else {
            // May exist, but not in this workspace
            LOG.warn("Could not find component '{}' was in registry '{}'", new Object[]{id, this.toString()});
            return null;
        }
    }

    public CMDComponentSpec getUncachedMDComponent(String id) throws ComponentRegistryException {
        try {
            return getUncachedMDComponent(id, componentDescriptionDao);
        } catch (DataAccessException ex) {
            throw new ComponentRegistryException("Database access error while trying to get component", ex);
        }
    }

    @Override
    public int register(AbstractDescription description, CMDComponentSpec spec) {
        enrichSpecHeader(spec, description);
        try {
            String xml = componentSpecToString(spec);
            // Convert principal name to user record id
            Number uid = convertUserInDescription(description);
            getDaoForDescription(description).insertDescription(description, xml, isPublic(), uid);
            invalidateCache(description);
            return 0;
        } catch (DataAccessException ex) {
            LOG.error("Database error while registering component", ex);
            return -1;
        } catch (JAXBException ex) {
            LOG.error("Error while registering component", ex);
            return -2;
        } catch (UnsupportedEncodingException ex) {
            LOG.error("Error while registering component", ex);
            return -3;
        }
    }

    @Override
    public int registerComment(Comment comment, String principalName) throws ComponentRegistryException {
        try {
            if (comment.getComponentDescriptionId() != null && componentDescriptionDao.isInRegistry(comment.getComponentDescriptionId(), getUserId())
                    || comment.getProfileDescriptionId() != null && profileDescriptionDao.isInRegistry(comment.getProfileDescriptionId(), getUserId())) {
                // Convert principal name to user record id
                Number uid = convertUserIdInComment(comment, principalName);
                // Set date to current date
                comment.setCommentDate(Comment.createNewDate());
                Number commentId = commentsDao.insertComment(comment, uid);
                comment.setId(commentId.toString());
            } else {
                throw new ComponentRegistryException("Cannot insert comment into this registry. Unknown profileId or componentId");
            }
            return 0;
        } catch (DataAccessException ex) {
            LOG.error("Database error while registering component", ex);
            return -1;
        }
    }

    /**
     * Calling service sets user id to principle. Our task is to convert this to
     * an id for later reference. If none is set and this is a user's workspace,
     * set from that user's id.
     *
     * It also sets the name in the description according to the display name in the database.
     *
     * @param description
     * Description containing principle name as userId
     * @return Id (from database)
     * @throws DataAccessException
     */
    private Number convertUserInDescription(AbstractDescription description) throws DataAccessException {
        Number uid = null;
        String name = null;
        if (description.getUserId() != null) {
            RegistryUser user = userDao.getByPrincipalName(description.getUserId());
            if (user != null) {
                uid = user.getId();
                name = user.getName();
            }
        } else {
            uid = getUserId(); // this can be null as well
        }
        if (uid != null) {
            description.setUserId(uid.toString());
        }
        if (name != null) {
            description.setCreatorName(name);
        }
        return uid;
    }

    /**
     * Calling service sets user id to principle. Our task is to convert this to
     * an id for later reference. If none is set and this is a user's workspace,
     * set from that user's id.
     *
     * @param comment
     * Comment containing principle name as userId
     * @return Id (from database)
     * @throws DataAccessException
     */
    private Number convertUserIdInComment(Comment comment, String principalName) throws DataAccessException, ComponentRegistryException {
        if (principalName != null) {
            RegistryUser user = userDao.getByPrincipalName(principalName);
            if (user != null) {
                Number id = user.getId();
                if (id != null) {
                    // Set user id in comment for convenience of calling method 
                    comment.setUserId(id.toString());
                    // Set name to user's preferred display name
                    comment.setUserName(user.getName());
                    return id;
                } else {
                    throw new ComponentRegistryException("Cannot find user with principal name: " + principalName);
                }
            }
        }
        return null;
    }

    @Override
    public int update(AbstractDescription description, CMDComponentSpec spec, Principal principal, boolean forceUpdate) {
        try {
            checkAuthorisation(description, principal);
            checkAge(description, principal);
            // For public components, check if used in other components or profiles (unless forced)
            if (!forceUpdate && this.isPublic() && !description.isProfile()) {
                checkStillUsed(description.getId());
            }
            AbstractDescriptionDao<?> dao = getDaoForDescription(description);
            dao.updateDescription(getIdForDescription(description), description, componentSpecToString(spec));
            invalidateCache(description);
            return 0;
        } catch (JAXBException ex) {
            LOG.error("Error while updating component", ex);
            return -1;
        } catch (UnsupportedEncodingException ex) {
            LOG.error("Error while updating component", ex);
            return -1;
        } catch (IllegalArgumentException ex) {
            LOG.error("Error while updating component", ex);
            return -1;
        } catch (UserUnauthorizedException e) {
            LOG.error("Error while updating component", e);
            return -1;
        } catch (DeleteFailedException e) {
            LOG.error("Error while updating component", e);
            return -1;
        } catch (ComponentRegistryException e) {
            LOG.error("Error while updating component", e);
            return -1;
        }
    }

    @Override
    public int publish(AbstractDescription desc, CMDComponentSpec spec, Principal principal) {
        int result = 0;
        AbstractDescriptionDao<?> dao = getDaoForDescription(desc);
        if (!isPublic()) { // if already in public workspace there is nothing todo
            desc.setHref(AbstractDescription.createPublicHref(desc.getHref()));
            Number id = getIdForDescription(desc);
            try {
                // Update description & content
                dao.updateDescription(id, desc, componentSpecToString(spec));
                // Set to public
                dao.setPublished(id, true);
            } catch (DataAccessException ex) {
                LOG.error("Database error while updating component", ex);
                return -1;
            } catch (JAXBException ex) {
                LOG.error("Error while updating component", ex);
                return -2;
            } catch (UnsupportedEncodingException ex) {
                LOG.error("Error while updating component", ex);
                return -3;
            }
        }
        return result;
    }

    @Override
    public void getMDProfileAsXml(String profileId, OutputStream output) throws ComponentRegistryException {
        CMDComponentSpec expandedSpec = CMDComponentSpecExpanderDbImpl.expandProfile(profileId, this);
        writeXml(expandedSpec, output);
    }

    @Override
    public void getMDProfileAsXsd(String profileId, OutputStream outputStream) throws ComponentRegistryException {
        CMDComponentSpec expandedSpec = CMDComponentSpecExpanderDbImpl.expandProfile(profileId, this);
        writeXsd(expandedSpec, outputStream);
    }

    @Override
    public void getMDComponentAsXml(String componentId, OutputStream output) throws ComponentRegistryException {
        CMDComponentSpec expandedSpec = CMDComponentSpecExpanderDbImpl.expandComponent(componentId, this);
        writeXml(expandedSpec, output);
    }

    @Override
    public void getMDComponentAsXsd(String componentId, OutputStream outputStream) throws ComponentRegistryException {
        CMDComponentSpec expandedSpec = CMDComponentSpecExpanderDbImpl.expandComponent(componentId, this);
        writeXsd(expandedSpec, outputStream);
    }

    @Override
    public void deleteMDProfile(String profileId, Principal principal) throws UserUnauthorizedException, DeleteFailedException,
            ComponentRegistryException {
        ProfileDescription desc = getProfileDescription(profileId);
        if (desc != null) {
            try {
                checkAuthorisation(desc, principal);
                checkAge(desc, principal);
                profileDescriptionDao.setDeleted(desc, true);
                invalidateCache(desc);
            } catch (DataAccessException ex) {
                throw new DeleteFailedException("Database access error while trying to delete profile", ex);
            }
        }
    }

    @Override
    public void deleteMDComponent(String componentId, Principal principal, boolean forceDelete) throws UserUnauthorizedException,
            DeleteFailedException, ComponentRegistryException {
        ComponentDescription desc = componentDescriptionDao.getByCmdId(componentId);
        if (desc != null) {
            try {
                checkAuthorisation(desc, principal);
                checkAge(desc, principal);

                if (!forceDelete) {
                    checkStillUsed(componentId);
                }
                componentDescriptionDao.setDeleted(desc, true);
                invalidateCache(desc);
            } catch (DataAccessException ex) {
                throw new DeleteFailedException("Database access error while trying to delete component", ex);
            }
        }
    }

    /**
     *
     * @return whether this is the public registry
     * @deprecated use {@link #getStatus() } to check if this is the {@link ComponentStatus#PUBLIC public registry}
     */
    @Override
    @Deprecated
    public boolean isPublic() {
        return status == ComponentStatus.PUBLIC;
    }

    /**
     * @return The user id, or null if there is no owner or it is not a user.
     */
    private Number getUserId() {
        if (owner instanceof OwnerUser) {
            return owner.getId();
        } else {
            return null;
        }
    }

    /**
     * @return The group id, or null if there is no owner or it is not a group.
     */
    private Number getGroupId() {
        if (owner instanceof OwnerGroup) {
            return owner.getId();
        } else {
            return null;
        }
    }

    @Override
    public Owner getOwner() {
        return owner;
    }

    /**
     * Sets status and owner of this registry
     *
     * @param status new status for registry
     * @param owner new owner for registry
     */
    public void setStatus(ComponentStatus status, Owner owner) {
        setStatus(status);
        this.owner = owner;
    }

    public void setStatus(ComponentStatus status) {
        this.status = status;
    }

    @Override
    public ComponentStatus getStatus() {
        return status;
    }

    private void invalidateCache(AbstractDescription description) {
        if (description.isProfile()) {
            profilesCache.remove(description.getId());
        } else {
            componentsCache.remove(description.getId());
        }
    }

    private AbstractDescriptionDao<?> getDaoForDescription(AbstractDescription description) {
        return description.isProfile() ? profileDescriptionDao : componentDescriptionDao;
    }

    /**
     * Looks up description on basis of CMD Id. This will also check if such a
     * record even exists.
     *
     * @param description
     * Description to look up
     * @return Database id for description
     * @throws IllegalArgumentException
     * If description with non-existing id is passed
     */
    private Number getIdForDescription(AbstractDescription description) throws IllegalArgumentException {
        Number dbId = null;
        AbstractDescriptionDao<?> dao = getDaoForDescription(description);
        try {
            dbId = dao.getDbId(description.getId());
        } catch (DataAccessException ex) {
            LOG.error("Error getting dbId for component with id " + description.getId(), ex);
        }
        if (dbId == null) {
            throw new IllegalArgumentException("Could not get database Id for description");
        } else {
            return dbId;
        }
    }

    private String componentSpecToString(CMDComponentSpec spec) throws UnsupportedEncodingException, JAXBException {
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        MDMarshaller.marshal(spec, os);
        String xml = os.toString("UTF-8");
        return xml;
    }

    private CMDComponentSpec getUncachedMDComponent(String id, AbstractDescriptionDao dao) {
        String xml = dao.getContent(false, id);
        if (xml != null) {
            try {
                InputStream is = new ByteArrayInputStream(xml.getBytes("UTF-8"));
                return MDMarshaller.unmarshal(CMDComponentSpec.class, is, null);

            } catch (JAXBException ex) {
                LOG.error(null, ex);
            } catch (UnsupportedEncodingException ex) {
                LOG.error(null, ex);
            }
        }
        return null;
    }

    private void checkAuthorisation(AbstractDescription desc, Principal principal) throws UserUnauthorizedException {
        if (!isOwnerOfDescription(desc, principal.getName()) && !configuration.isAdminUser(principal)) {
            throw new UserUnauthorizedException("Unauthorized operation user '" + principal.getName()
                    + "' is not the creator (nor an administrator) of the " + (desc.isProfile() ? "profile" : "component") + "(" + desc
                    + ").");
        }
    }

    private void checkAuthorisationComment(Comment desc, Principal principal) throws UserUnauthorizedException {
        if (!isOwnerOfComment(desc, principal.getName()) && !configuration.isAdminUser(principal)) {
            throw new UserUnauthorizedException("Unauthorized operation user '" + principal.getName()
                    + "' is not the creator (nor an administrator) of the " + (desc.getId()) + "(" + desc
                    + ").");
        }
    }

    private boolean isOwnerOfDescription(AbstractDescription desc, String principalName) {
        String owner = getDaoForDescription(desc).getOwnerPrincipalName(getIdForDescription(desc));
        return owner != null // If owner is null, no one can be owner
                && principalName.equals(owner);
    }

    private boolean isOwnerOfComment(Comment com, String principalName) {
        String owner = commentsDao.getOwnerPrincipalName(Integer.parseInt(com.getId()));
        return owner != null // If owner is null, no one can be owner
                && principalName.equals(owner);
    }

    private void checkAge(AbstractDescription desc, Principal principal) throws DeleteFailedException {
        if (isPublic() && !configuration.isAdminUser(principal)) {
            try {
                Date regDate = AbstractDescription.getDate(desc.getRegistrationDate());
                Calendar calendar = Calendar.getInstance();
                calendar.set(Calendar.MONTH, calendar.get(Calendar.MONTH) - 1);
                if (regDate.before(calendar.getTime())) { // More then month old
                    throw new DeleteFailedException(
                            "The "
                            + (desc.isProfile() ? "Profile" : "Component")
                            + " is more then a month old and cannot be deleted anymore. It might have been used to create metadata, deleting it would invalidate that metadata.");
                }
            } catch (ParseException e) {
                LOG.error("Cannot parse date of " + desc + " Error:" + e);
            }
        }
    }

    private boolean inWorkspace(AbstractDescriptionDao<?> dao, String cmdId) {
        if (isPublic()) {
            return dao.isPublic(cmdId);
        } else {
            return dao.isInUserSpace(cmdId, getUserId());
        }
    }

    @Override
    public String getName() {
        if (isPublic()) {
            return ComponentRegistry.PUBLIC_NAME;
        } else {
            return "Registry of " + userDao.getById(getUserId()).getName();
        }
    }

    @Override
    public List<ProfileDescription> getDeletedProfileDescriptions() {
        return profileDescriptionDao.getDeletedDescriptions(getUserId());
    }

    @Override
    public List<ComponentDescription> getDeletedComponentDescriptions() {
        return componentDescriptionDao.getDeletedDescriptions(getUserId());
    }

    @Override
    public void deleteComment(String commentId, Principal principal) throws IOException,
            ComponentRegistryException, UserUnauthorizedException, DeleteFailedException {
        try {
            Comment comment = commentsDao.getById(Integer.parseInt(commentId));
            if (comment != null
                    // Comment must have an existing (in this registry) componentId or profileId
                    && (comment.getComponentDescriptionId() != null && componentDescriptionDao.isInRegistry(comment.getComponentDescriptionId(), getUserId())
                    || comment.getProfileDescriptionId() != null && profileDescriptionDao.isInRegistry(comment.getProfileDescriptionId(), getUserId()))) {
                checkAuthorisationComment(comment, principal);
                commentsDao.deleteComment(comment);
            } else {
                // Comment exists in DB, but component is not in this registry
                throw new ComponentRegistryException("Comment " + commentId + " cannot be found in specified registry");
            }
        } catch (DataAccessException ex) {
            throw new DeleteFailedException("Database access error while trying to delete component", ex);
        } catch (NumberFormatException ex) {
            throw new DeleteFailedException("Illegal comment ID, cannot parse integer", ex);
        }
    }

    @Override
    public CMDComponentSpecExpander getExpander() {
        return new CMDComponentSpecExpanderDbImpl(this);
    }

    @Override
    public String toString() {
        return getName();
    }
}