cmslockmanager.java

cms是开源的框架

    /**
     * Proves if a resource is locked.<p>
     * 
     * Use {@link org.opencms.lock.CmsLockManager#getLock(CmsDriverManager, CmsDbContext, CmsResource)} 
     * to obtain a CmsLock object for the specified resource to get further information 
     * about how the resource is locked.<p>
     * 
     * @param driverManager the driver manager
     * @param dbc the current database context
     * @param resource the resource
     * 
     * @return true, if and only if the resource is currently locked
     * @throws CmsException if something goes wrong
     */
    public boolean isLocked(CmsDriverManager driverManager, CmsDbContext dbc, CmsResource resource) throws CmsException {

        CmsLock lock = getLock(driverManager, dbc, resource);
        return !lock.isNullLock();
    }

    /**
     * Removes a resource after it has been deleted by the driver manager.<p>
     * 
     * @param driverManager the driver manager
     * @param dbc the current database context
     * @param resourceName the root path of the deleted resource
     * @throws CmsException if something goes wrong
     */
    public void removeDeletedResource(CmsDriverManager driverManager, CmsDbContext dbc, String resourceName)
    throws CmsException {

        boolean resourceExists;
        try {
            driverManager.getVfsDriver().readResource(dbc, dbc.currentProject().getId(), resourceName, false);
            resourceExists = true;
        } catch (CmsVfsResourceNotFoundException e) {
            resourceExists = false;
        }

        if (resourceExists) {
            throw new CmsLockException(Messages.get().container(
                Messages.ERR_REMOVING_UNDELETED_RESOURCE_1,
                dbc.getRequestContext().removeSiteRoot(resourceName)));
        }

        m_exclusiveLocks.remove(resourceName);
    }

    /**
     * Removes a resource from the lock manager.<p>
     * 
     * The forceUnlock option should be used with caution. forceUnlock will remove the lock
     * by ignoring any rules which may cause wrong lock states.<p>
     * 
     * @param driverManager the driver manager
     * @param dbc the current database context
     * @param resource the resource
     * @param forceUnlock true, if a resource is forced to get unlocked, no matter by which user and in which project the resource is currently locked
     * 
     * @return the previous CmsLock object of the resource, or null if the resource was unlocked
     *
     * @throws CmsException if something goes wrong
     */
    public CmsLock removeResource(
        CmsDriverManager driverManager,
        CmsDbContext dbc,
        CmsResource resource,
        boolean forceUnlock) throws CmsException {

        String resourcename = resource.getRootPath();
        CmsLock lock = getLock(driverManager, dbc, resource);
        CmsResource sibling = null;

        // check some abort conditions first

        if (lock.isNullLock()) {
            // the resource isn't locked
            return null;
        }

        if (!forceUnlock
            && (!lock.getUserId().equals(dbc.currentUser().getId()) || lock.getProjectId() != dbc.currentProject().getId())) {
            // the resource is locked by another user
            throw new CmsLockException(Messages.get().container(
                Messages.ERR_RESOURCE_UNLOCK_1,
                dbc.removeSiteRoot(resourcename)));
        }

        if (!forceUnlock
            && (lock.getType() == CmsLock.TYPE_INHERITED || lock.getType() == CmsLock.TYPE_SHARED_INHERITED || (getParentFolderLock(resourcename) != null))) {
            // sub-resources of a locked folder can't be unlocked
            throw new CmsLockException(Messages.get().container(
                Messages.ERR_UNLOCK_LOCK_INHERITED_1,
                dbc.removeSiteRoot(resourcename)));
        }

        // remove the lock and clean-up stuff
        if (lock.getType() == CmsLock.TYPE_EXCLUSIVE) {
            if (resource.isFolder()) {
                // in case of a folder, remove any exclusive locks on sub-resources that probably have
                // been upgraded from an inherited lock when the user edited a resource                
                Iterator i = m_exclusiveLocks.keySet().iterator();
                String lockedPath = null;

                while (i.hasNext()) {
                    lockedPath = (String)i.next();
                    if (lockedPath.startsWith(resourcename) && !lockedPath.equals(resourcename)) {
                        // remove the exclusive locked sub-resource
                        i.remove();
                    }
                }
            }

            return (CmsLock)m_exclusiveLocks.remove(resourcename);
        }

        if (lock.getType() == CmsLock.TYPE_SHARED_EXCLUSIVE) {
            // when a resource with a shared lock gets unlocked, fetch all siblings of the resource 
            // to the same content record to identify the exclusive locked sibling
            List siblings = internalReadSiblings(driverManager, dbc, resource);

            for (int i = 0; i < siblings.size(); i++) {
                sibling = (CmsResource)siblings.get(i);

                if (m_exclusiveLocks.containsKey(sibling.getRootPath())) {
                    // remove the exclusive locked sibling
                    m_exclusiveLocks.remove(sibling.getRootPath());
                    break;
                }
            }

            return lock;
        }

        return lock;
    }

    /**
     * Removes all resources that are exclusively locked in a project.<p>
     * 
     * @param projectId the ID of the project where the resources have been locked
     */
    public void removeResourcesInProject(int projectId) {

        Iterator i = m_exclusiveLocks.keySet().iterator();
        CmsLock currentLock = null;

        while (i.hasNext()) {
            currentLock = (CmsLock)m_exclusiveLocks.get(i.next());

            if (currentLock.getProjectId() == projectId) {
                // iterators are fail-fast!
                i.remove();
            }
        }
    }

    /**
     * Removes all exclusive temporary locks of a user.<p>
     * 
     * @param userId the ID of the user whose locks are removed
     */
    public void removeTempLocks(CmsUUID userId) {

        Iterator i = m_exclusiveLocks.keySet().iterator();
        CmsLock currentLock = null;

        while (i.hasNext()) {
            currentLock = (CmsLock)m_exclusiveLocks.get(i.next());

            if (currentLock.getUserId().equals(userId) && currentLock.getMode() == CmsLock.TEMPORARY) {
                // iterators are fail-fast!
                i.remove();
            }
        }
    }

    /**
     * Returns the number of exclusive locked resources.<p>
     * 
     * @return the number of exclusive locked resources
     */
    public int size() {

        return m_exclusiveLocks.size();
    }

    /** 
     * @see java.lang.Object#toString()
     */
    public String toString() {

        // bring the list of locked resources into a human readable order first
        List lockedResources = new ArrayList(m_exclusiveLocks.keySet());
        Collections.sort(lockedResources);

        Iterator i = lockedResources.iterator();
        StringBuffer buf = new StringBuffer();
        String lockedPath = null;
        CmsLock currentLock = null;

        while (i.hasNext()) {
            lockedPath = (String)i.next();
            currentLock = (CmsLock)m_exclusiveLocks.get(lockedPath);
            buf.append(currentLock.toString()).append("\n");
        }

        return buf.toString();
    }

    /**
     * @see java.lang.Object#finalize()
     */
    protected void finalize() throws Throwable {

        try {
            if (m_exclusiveLocks != null) {
                m_exclusiveLocks.clear();

                m_exclusiveLocks = null;
                sharedInstance = null;
            }
        } catch (Throwable t) {
            // ignore
        }
        super.finalize();
    }

    /**
     * Returns the lock of a possible locked parent folder of a resource.<p>
     * 
     * @param resourcename the name of the resource
     * @return the lock of a parent folder, or null if no parent folders are locked
     */
    private CmsLock getParentFolderLock(String resourcename) {

        String lockedPath = null;
        List keys = new ArrayList(m_exclusiveLocks.keySet());

        for (int i = 0; i < keys.size(); i++) {
            lockedPath = (String)keys.get(i);

            if (resourcename.startsWith(lockedPath) && !resourcename.equals(lockedPath) && lockedPath.endsWith("/")) {
                return (CmsLock)m_exclusiveLocks.get(lockedPath);
            }

        }

        return null;
    }

    /**
     * Reads all siblings from a given resource.<p>
     * 
     * The result is a list of <code>{@link CmsResource}</code> objects. 
     * It does NOT contain the resource itself, only the siblings of the resource.<p>
     * 
     * @param driverManager the driver manager
     * @param dbc the current database context
     * @param resource the resource to find all siblings from
     * 
     * @return a list of <code>{@link CmsResource}</code> Objects that 
     *          are siblings to the specified resource, 
     *          excluding the specified resource itself
     * 
     * @throws CmsException if something goes wrong
     */
    private List internalReadSiblings(CmsDriverManager driverManager, CmsDbContext dbc, CmsResource resource)
    throws CmsException {

        // reading siblings using the DriverManager methods while the lock state is checked would
        // inevitably result in an infinite loop...        

        List siblings = driverManager.getVfsDriver().readSiblings(dbc, dbc.currentProject(), resource, true);
        siblings.remove(resource);

        return driverManager.updateContextDates(dbc, siblings);
    }
}