Java tutorial
/* * #%L * Alfresco Remote API * %% * Copyright (C) 2005 - 2016 Alfresco Software Limited * %% * This file is part of the Alfresco software. * If the software was purchased under a paid Alfresco license, the terms of * the paid license agreement will prevail. Otherwise, the software is * provided under the following open source license terms: * * Alfresco 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 3 of the License, or * (at your option) any later version. * * Alfresco 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. * * You should have received a copy of the GNU Lesser General Public License * along with Alfresco. If not, see <http://www.gnu.org/licenses/>. * #L% */ package org.alfresco.repo.webdav; import java.util.ArrayList; import java.util.List; import javax.servlet.http.HttpSession; import org.alfresco.model.ContentModel; import org.alfresco.repo.lock.LockUtils; import org.alfresco.repo.lock.mem.Lifetime; import org.alfresco.repo.lock.mem.LockState; import org.alfresco.repo.security.authentication.AuthenticationUtil; import org.alfresco.repo.security.authentication.AuthenticationUtil.RunAsWork; import org.alfresco.repo.transaction.RetryingTransactionHelper.RetryingTransactionCallback; import org.alfresco.service.cmr.coci.CheckOutCheckInService; import org.alfresco.service.cmr.lock.LockService; import org.alfresco.service.cmr.lock.LockStatus; import org.alfresco.service.cmr.lock.LockType; import org.alfresco.service.cmr.repository.NodeRef; import org.alfresco.service.cmr.repository.NodeService; import org.alfresco.service.transaction.TransactionService; import org.alfresco.util.Pair; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; /** * <p> * WebDAVLockService is used to manage file locks for WebDAV and Sharepoint protocol. It ensures a lock never persists * for more than 24 hours, and also ensures locks are timed out on session timeout. * * @author Pavel.Yurkevich */ public class WebDAVLockServiceImpl implements WebDAVLockService { /** The session attribute under which webdav/vti stores its locked documents. */ private static final String LOCKED_RESOURCES = "_webdavLockedResources"; private static Log logger = LogFactory.getLog(WebDAVLockServiceImpl.class); private static ThreadLocal<HttpSession> currentSession = new ThreadLocal<HttpSession>(); private LockService lockService; private NodeService nodeService; private TransactionService transactionService; private CheckOutCheckInService checkOutCheckInService; /** * Set the LockService * * @param lockService LockService */ public void setLockService(LockService lockService) { this.lockService = lockService; } /** * Set the NodeService * * @param nodeService NodeService */ public void setNodeService(NodeService nodeService) { this.nodeService = nodeService; } /** * Set the TransactionService * * @param transactionService TransactionService */ public void setTransactionService(TransactionService transactionService) { this.transactionService = transactionService; } /** * Set the CheckOutCheckInService * * @param checkOutCheckInService CheckOutCheckInService */ public void setCheckOutCheckInService(CheckOutCheckInService checkOutCheckInService) { this.checkOutCheckInService = checkOutCheckInService; } /** * Caches current session to the thread local variable * * @param session HttpSession */ @Override public void setCurrentSession(HttpSession session) { currentSession.set(session); } @Override @SuppressWarnings("unchecked") public void sessionDestroyed() { HttpSession session = currentSession.get(); if (session == null) { if (logger.isDebugEnabled()) { logger.debug("Couldn't find current session."); } return; } // look for locked documents list in http session final List<Pair<String, NodeRef>> lockedResources = (List<Pair<String, NodeRef>>) session .getAttribute(LOCKED_RESOURCES); if (lockedResources != null && lockedResources.size() > 0) { if (logger.isDebugEnabled()) { logger.debug( "Found " + lockedResources.size() + " locked resources for session: " + session.getId()); } for (Pair<String, NodeRef> lockedResource : lockedResources) { String runAsUser = lockedResource.getFirst(); final NodeRef nodeRef = lockedResource.getSecond(); // there are some document that should be forcibly unlocked AuthenticationUtil.runAs(new RunAsWork<Void>() { @Override public Void doWork() throws Exception { return transactionService.getRetryingTransactionHelper() .doInTransaction(new RetryingTransactionCallback<Void>() { @Override public Void execute() throws Throwable { // check whether this document still exists in repo if (nodeService.exists(nodeRef)) { if (logger.isDebugEnabled()) { logger.debug("Trying to release lock for: " + nodeRef); } // check the lock status of document LockStatus lockStatus = lockService.getLockStatus(nodeRef); // check if document was checked out boolean hasWorkingCopy = checkOutCheckInService .getWorkingCopy(nodeRef) != null; boolean isWorkingCopy = nodeService.hasAspect(nodeRef, ContentModel.ASPECT_WORKING_COPY); // forcibly unlock document if it is still locked and not checked out if ((lockStatus.equals(LockStatus.LOCKED) || lockStatus.equals(LockStatus.LOCK_OWNER)) && !hasWorkingCopy && !isWorkingCopy) { try { // try to unlock it lockService.unlock(nodeRef); if (logger.isDebugEnabled()) { logger.debug( "Lock was successfully released for: " + nodeRef); } } catch (Exception e) { if (logger.isDebugEnabled()) { logger.debug("Unable to unlock " + nodeRef + " cause: " + e.getMessage()); } } } else { // document is not locked or is checked out if (logger.isDebugEnabled()) { logger.debug("Skip lock releasing for: " + nodeRef + " as it is not locked or is checked out"); } } } else { // document no longer exists in repo if (logger.isDebugEnabled()) { logger.debug( "Skip lock releasing for an unexisting node: " + nodeRef); } } return null; } }, transactionService.isReadOnly()); } }, runAsUser == null ? AuthenticationUtil.getSystemUserName() : runAsUser); } } else { // there are no documents with unexpected lock left on it if (logger.isDebugEnabled()) { logger.debug("No locked resources were found for session: " + session.getId()); } } } public void lock(NodeRef nodeRef, LockInfo lockInfo) { boolean performSessionBehavior = false; long timeout; timeout = lockInfo.getRemainingTimeoutSeconds(); // ALF-11777 fix, do not lock node for more than 24 hours (webdav and vti) if (timeout >= WebDAV.TIMEOUT_24_HOURS || timeout == WebDAV.TIMEOUT_INFINITY) { timeout = WebDAV.TIMEOUT_24_HOURS; lockInfo.setTimeoutSeconds((int) timeout); performSessionBehavior = true; } // TODO: lock children according to depth? lock type? final String additionalInfo = lockInfo.toJSON(); lockService.lock(nodeRef, LockType.WRITE_LOCK, (int) timeout, Lifetime.EPHEMERAL, additionalInfo); if (logger.isDebugEnabled()) { logger.debug(nodeRef + " was locked for " + timeout + " seconds."); } if (performSessionBehavior) { HttpSession session = currentSession.get(); if (session == null) { if (logger.isDebugEnabled()) { logger.debug("Couldn't find current session."); } return; } storeObjectInSessionList(session, LOCKED_RESOURCES, new Pair<String, NodeRef>(AuthenticationUtil.getRunAsUser(), nodeRef)); if (logger.isDebugEnabled()) { logger.debug(nodeRef + " was added to the session " + session.getId() + " for post expiration processing."); } } } /** * Shared method for webdav/vti protocols to lock node. If node is locked for more than 24 hours it is automatically added * to the current session locked resources list. * * @param nodeRef the node to lock * @param userName userName * @param timeout the number of seconds before the locks expires */ @Override public void lock(NodeRef nodeRef, String userName, int timeout) { LockInfo lockInfo = createLock(nodeRef, userName, true, timeout); lock(nodeRef, lockInfo); } /** * Shared method for webdav/vti to unlock node. Unlocked node is automatically removed from * current sessions's locked resources list. * * @param nodeRef the node to lock */ @Override public void unlock(NodeRef nodeRef) { lockService.unlock(nodeRef); if (logger.isDebugEnabled()) { logger.debug(nodeRef + " was unlocked."); } HttpSession session = currentSession.get(); if (session == null) { if (logger.isDebugEnabled()) { logger.debug("Couldn't find current session."); } return; } boolean removed = removeObjectFromSessionList(session, LOCKED_RESOURCES, new Pair<String, NodeRef>(AuthenticationUtil.getRunAsUser(), nodeRef)); if (removed && logger.isDebugEnabled()) { logger.debug(nodeRef + " was removed from the session " + session.getId()); } } /** * Gets the lock status for the node reference relative to the current user. * * @see LockService#getLockStatus(org.alfresco.service.cmr.repository.NodeRef, String) * * @param nodeRef the node reference * @return the lock status */ @Override public LockInfo getLockInfo(NodeRef nodeRef) { LockInfo lockInfo = null; LockState lockState = lockService.getLockState(nodeRef); if (lockState != null) { String additionalInfo = lockState.getAdditionalInfo(); try { lockInfo = LockInfoImpl.fromJSON(additionalInfo); } catch (IllegalArgumentException e) { lockInfo = new LockInfoImpl(); } lockInfo.setExpires(lockState.getExpires()); lockInfo.setOwner(lockState.getOwner()); } return lockInfo; } /** * Determines if the node is locked AND it's not a WRITE_LOCK for the current user.<p> * * @return true if the node is locked AND it's not a WRITE_LOCK for the current user */ public boolean isLockedAndReadOnly(NodeRef nodeRef) { return this.lockService.isLockedAndReadOnly(nodeRef); } /** * Add the given <code>object</code> to the session list that is stored in session under <code>listName</code> attribute * * @param session the session * @param listName the list name (session attribute name) * @param object the object to store in session list */ @SuppressWarnings("unchecked") private static final void storeObjectInSessionList(HttpSession session, String listName, Object object) { List<Object> list = null; synchronized (session) { list = (List<Object>) session.getAttribute(listName); if (list == null) { list = new ArrayList<Object>(); session.setAttribute(listName, list); } } synchronized (list) { if (!list.contains(object)) { list.add(object); } } } /** * Removes the given <code>object</code> from the session list that is stored in session under <code>listName</code> attribute * * @param session the session * @param listName the list name (session attribute name) * @param object the object to store in session list * * @return <tt>true</tt> if session list contained the specified element, otherwise <tt>false</tt> */ @SuppressWarnings("unchecked") private static final boolean removeObjectFromSessionList(HttpSession session, String listName, Object object) { List<Object> list = null; synchronized (session) { list = (List<Object>) session.getAttribute(listName); } if (list == null) { return false; } synchronized (list) { return list.remove(object); } } /** * Create a new lock * * @param nodeRef NodeRef * @param userName String * @param createExclusive boolean * @param timeoutSecs int */ private LockInfo createLock(NodeRef nodeRef, String userName, boolean createExclusive, int timeoutSecs) { // Create Lock token String lockToken = WebDAV.makeLockToken(nodeRef, userName); LockInfo lockInfo = new LockInfoImpl(); if (createExclusive) { // Lock the node lockInfo.setTimeoutSeconds(timeoutSecs); lockInfo.setExclusiveLockToken(lockToken); } else { lockInfo.addSharedLockToken(lockToken); } // Store lock depth lockInfo.setDepth(WebDAV.getDepthName(WebDAV.DEPTH_INFINITY)); // Store lock scope (shared/exclusive) String scope = createExclusive ? WebDAV.XML_EXCLUSIVE : WebDAV.XML_SHARED; lockInfo.setScope(scope); // Store the owner of this lock lockInfo.setOwner(userName); // TODO: to help with debugging/refactoring (remove later) String currentUser = AuthenticationUtil.getFullyAuthenticatedUser(); if (!currentUser.equals(userName)) { throw new IllegalStateException( "Node is being locked for user " + userName + " by (different/current) user " + currentUser); } return lockInfo; } }