Java tutorial
/********************************************************************************** * $URL: https://source.sakaiproject.org/contrib/conditionalrelease/tags/sakai_2-4-1/impl/src/java/org/sakaiproject/conditions/impl/ResourceReleaseRule.java $ * $Id: ResourceReleaseRule.java 44304 2007-12-17 04:35:22Z zach.thomas@txstate.edu $ *********************************************************************************** * * Copyright (c) 2003, 2004, 2005, 2006, 2007, 2008 Sakai Foundation * * Licensed under the Educational Community License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.opensource.org/licenses/ECL-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. * **********************************************************************************/ package org.sakaiproject.conditions.impl; import java.util.*; import org.apache.commons.collections.Predicate; import org.apache.commons.collections.PredicateUtils; import org.sakaiproject.authz.api.AuthzGroup; import org.sakaiproject.authz.api.GroupNotDefinedException; import org.sakaiproject.authz.api.Member; import org.sakaiproject.authz.api.SecurityAdvisor; import org.sakaiproject.authz.api.AuthzGroupService; import org.sakaiproject.authz.api.SecurityService; import org.sakaiproject.component.cover.ComponentManager; import org.sakaiproject.conditions.api.Condition; import org.sakaiproject.conditions.api.ConditionService; import org.sakaiproject.conditions.api.Rule; import org.sakaiproject.content.api.ContentCollectionEdit; import org.sakaiproject.content.api.ContentResourceEdit; import org.sakaiproject.content.api.GroupAwareEdit; import org.sakaiproject.content.api.ContentHostingService; import org.sakaiproject.entity.api.ResourceProperties; import org.sakaiproject.event.api.Event; import org.sakaiproject.event.api.Notification; import org.sakaiproject.event.api.NotificationAction; import org.sakaiproject.event.api.NotificationService; import org.sakaiproject.event.api.Obsoletable; import org.sakaiproject.exception.IdUnusedException; import org.sakaiproject.exception.InUseException; import org.sakaiproject.exception.OverQuotaException; import org.sakaiproject.exception.PermissionException; import org.sakaiproject.exception.ServerOverloadException; import org.sakaiproject.exception.TypeException; import org.w3c.dom.Element; import org.w3c.dom.Node; import org.w3c.dom.NodeList; /** * @author zach * */ public class ResourceReleaseRule implements Rule, Obsoletable { private static final String SATISFIES_RULE = "resource.satisfies.rule"; private static final long LENGTH_OF_A_DAY = 86400000; // length of a day in milliseconds private String resourceId; private List<Condition> predicates; private Conjunction conj; private ContentHostingService chs = (ContentHostingService) ComponentManager .get("org.sakaiproject.content.api.ContentHostingService"); public void setContentHostingService(ContentHostingService chs) { this.chs = chs; } private ConditionService conditionService = (ConditionService) ComponentManager .get("org.sakaiproject.conditions.api.ConditionService"); public void setConditionService(ConditionService conditionService) { this.conditionService = conditionService; } private SecurityService securityService = (SecurityService) ComponentManager .get("org.sakaiproject.authz.api.SecurityService"); public void setSecurityService(SecurityService securityService) { this.securityService = securityService; } private AuthzGroupService authzGroupService = (AuthzGroupService) ComponentManager .get("org.sakaiproject.authz.api.AuthzGroupService");; public void setAuthzGroupService(AuthzGroupService authzGroupService) { this.authzGroupService = authzGroupService; } // we need a no-arg constructor so BaseNotificationService can instantiate these things with Class.forName(className).newInstance(); public ResourceReleaseRule() { } public ResourceReleaseRule(String resourceId, List<Condition> predicates, Conjunction conj) { this.resourceId = resourceId; this.predicates = predicates; this.conj = conj; } /* (non-Javadoc) * @see org.apache.commons.collections.Predicate#evaluate(java.lang.Object) */ public boolean evaluate(Object arg0) { Predicate judgement = new NullPredicate(); if (predicates.size() == 1) { judgement = predicates.get(0); } else { if (conj == Conjunction.AND) { judgement = PredicateUtils.allPredicate(predicates); } else if (conj == Conjunction.OR) { judgement = PredicateUtils.anyPredicate(predicates); } } return judgement.evaluate(arg0); } /* (non-Javadoc) * @see org.sakaiproject.event.api.NotificationAction#getClone() */ public NotificationAction getClone() { // TODO Auto-generated method stub return null; } /* (non-Javadoc) * @see org.sakaiproject.event.api.NotificationAction#notify(org.sakaiproject.event.api.Notification, org.sakaiproject.event.api.Event) */ public void notify(Notification notification, Event event) { securityService.pushAdvisor(new SecurityAdvisor() { public SecurityAdvice isAllowed(String userId, String function, String reference) { return SecurityAdvice.ALLOWED; } }); if (this.isObsolete()) return; if (("gradebook.updateItemScore").equals(event.getEvent())) { AssignmentGrading grading = produceAssignmentGradingFromEvent(event); boolean shouldBeAvailable = this.evaluate(grading); // update access control list on ContentHostingService here try { GroupAwareEdit resource = null; if (chs.isCollection(this.resourceId)) { resource = chs.editCollection(this.resourceId); } else { resource = chs.editResource(this.resourceId); } ResourceProperties resourceProps = resource.getProperties(); // since we're following a per-user event now, the global rule property should be removed resourceProps.removeProperty(SATISFIES_RULE); List<String> prop = resourceProps.getPropertyList(ContentHostingService.CONDITIONAL_ACCESS_LIST); if (prop == null) prop = new ArrayList<String>(); Set<String> acl = new TreeSet<String>(prop); if ((shouldBeAvailable && acl.contains(grading.getUserId())) || (!shouldBeAvailable && !acl.contains(grading.getUserId()))) { // no change to the ACL necessary, but we still have to commit the change to SATISFIES_RULE if (chs.isCollection(this.resourceId)) { chs.commitCollection((ContentCollectionEdit) resource); } else { chs.commitResource((ContentResourceEdit) resource, NotificationService.NOTI_NONE); } securityService.popAdvisor(); return; } if (!shouldBeAvailable && acl.contains(grading.getUserId())) { // remove user from access list acl.remove(grading.getUserId()); // time to re-populate the property list, start by tearing it down // we only have to do it this way because props does not have a removePropertyFromList method resourceProps.removeProperty(ContentHostingService.CONDITIONAL_ACCESS_LIST); for (String id : acl) { resourceProps.addPropertyToList(ContentHostingService.CONDITIONAL_ACCESS_LIST, id); } } else if (shouldBeAvailable && !acl.contains(grading.getUserId())) { // add user to access list resourceProps.addPropertyToList(ContentHostingService.CONDITIONAL_ACCESS_LIST, grading.getUserId()); } if (chs.isCollection(this.resourceId)) { chs.commitCollection((ContentCollectionEdit) resource); } else { chs.commitResource((ContentResourceEdit) resource, NotificationService.NOTI_NONE); } } catch (PermissionException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IdUnusedException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (TypeException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InUseException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (OverQuotaException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ServerOverloadException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { securityService.popAdvisor(); } } else if ("gradebook.updateAssignment".equals(event.getEvent()) || ("cond+gradebook.updateAssignment").equals(event.getEvent()) || ("datetime.update".equals(event.getEvent()))) { // this availability applies to the whole Resource, not on a per-user basis // TODO set the resource availability // foo bar baz AssignmentUpdate update = produceAssignmentUpdateFromEvent(event); boolean shouldBeAvailable = this.evaluate(update); try { GroupAwareEdit resource = null; if (chs.isCollection(this.resourceId)) { resource = chs.editCollection(this.resourceId); } else { resource = chs.editResource(this.resourceId); } ResourceProperties resourceProps = resource.getProperties(); resourceProps.addProperty(SATISFIES_RULE, Boolean.valueOf(shouldBeAvailable).toString()); if (chs.isCollection(this.resourceId)) { chs.commitCollection((ContentCollectionEdit) resource); } else { chs.commitResource((ContentResourceEdit) resource, NotificationService.NOTI_NONE); } } catch (PermissionException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IdUnusedException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (TypeException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InUseException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (OverQuotaException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ServerOverloadException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { securityService.popAdvisor(); } } else if (("cond+gradebook.updateItemScore").equals(event.getEvent())) { // this event means the Rule has just been added // and we need to look at any scores that may have been recorded already try { String[] assignmentRefParts = event.getResource().split("/"); String[] resourceRefParts = this.resourceId.split("/"); String authzRef = "/site/" + resourceRefParts[2]; AuthzGroup group = authzGroupService.getAuthzGroup(authzRef); Set<Member> members = group.getMembers(); // build access control list up from scratch using site members Set<String> acl = new HashSet<String>(); for (Member member : members) { boolean shouldBeAvailable = false; if (member.getRole().getId().equals(group.getMaintainRole())) { // we don't bother putting maintainers in the ACL continue; } else { Map<String, String> scoreData = conditionService.getConditionProvider("gradebook").getData( "grades", assignmentRefParts[2] + "|" + assignmentRefParts[3] + "|" + member.getUserId()); String scoreString = scoreData.get("score"); Double score; try { score = Double.parseDouble(scoreString); } catch (NumberFormatException e) { score = null; } AssignmentGrading grading = produceAssignmentGrading(member.getUserId(), score); shouldBeAvailable = this.evaluate(grading); } if (shouldBeAvailable) acl.add(member.getUserId()); } // update state on this resource GroupAwareEdit resource = null; if (chs.isCollection(this.resourceId)) { resource = chs.editCollection(this.resourceId); } else { resource = chs.editResource(this.resourceId); } ResourceProperties resourceProps = resource.getProperties(); // since we're following a per-user event now, the global rule property should be removed resourceProps.removeProperty(SATISFIES_RULE); resourceProps.removeProperty(ContentHostingService.CONDITIONAL_ACCESS_LIST); for (String id : acl) { resourceProps.addPropertyToList(ContentHostingService.CONDITIONAL_ACCESS_LIST, id); } if (chs.isCollection(this.resourceId)) { chs.commitCollection((ContentCollectionEdit) resource); } else { chs.commitResource((ContentResourceEdit) resource, NotificationService.NOTI_NONE); } } catch (GroupNotDefinedException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IdUnusedException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (TypeException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (PermissionException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (InUseException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (OverQuotaException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ServerOverloadException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { securityService.popAdvisor(); } } } public boolean isObsolete() { securityService.pushAdvisor(new SecurityAdvisor() { public SecurityAdvice isAllowed(String userId, String function, String reference) { return SecurityAdvice.ALLOWED; } }); try { chs.getProperties(this.resourceId); return false; } catch (PermissionException e1) { return true; } catch (IdUnusedException e1) { return true; } finally { securityService.popAdvisor(); } } private AssignmentUpdate produceAssignmentUpdateFromEvent(Event event) { // event resource of the form: /gradebook/[gradebook id]/[assignment name]/[points possible]/[due date millis]/[is released]/[is included in course grade]/[has authz] AssignmentUpdate rv = new AssignmentUpdate(); if ("datetime.update".equals(event.getEvent())) { for (Predicate p : this.predicates) { if (((Condition) p).getArgument() != null) { Object arg = ((Condition) p).getArgument(); if ((arg instanceof String) && (((String) arg).startsWith("dateMillis:"))) { rv.setDueDate(new java.util.Date(Long.parseLong( ((String) ((Condition) p).getArgument()).substring("dateMillis:".length())))); } return rv; } } return rv; } String[] assignmentRefParts = event.getResource().split("/"); rv.setTitle(assignmentRefParts[3]); rv.setDueDate(new Date(Long.parseLong(assignmentRefParts[5]))); rv.setIncludedInCourseGrade(Boolean.parseBoolean(assignmentRefParts[7])); rv.setReleasedToStudents(Boolean.parseBoolean(assignmentRefParts[6])); // since we've received an update, we'd better update the predicates for (Predicate p : this.predicates) { if (((Condition) p).getArgument() != null) { Object arg = ((Condition) p).getArgument(); if ((arg instanceof String) && (((String) arg).startsWith("dateMillis:"))) { ((BooleanExpression) p).setArgument("dateMillis:" + rv.getDueDate().getTime()); } } } return rv; } private Date addADay(Date date) { return (date == null) ? null : new java.util.Date(date.getTime() + LENGTH_OF_A_DAY); } /* (non-Javadoc) * @see org.sakaiproject.event.api.NotificationAction#set(org.w3c.dom.Element) */ public void set(Element el) { // setup for predicates predicates = new Vector(); this.resourceId = el.getAttribute("resourceId"); String conjunction = el.getAttribute("conjunction"); if ("OR".equals(conjunction)) { this.conj = Rule.Conjunction.OR; } else if ("AND".equals(conjunction)) { this.conj = Rule.Conjunction.AND; } // the children (predicates) NodeList children = el.getChildNodes(); final int length = children.getLength(); for (int i = 0; i < length; i++) { Node child = children.item(i); if (child.getNodeType() != Node.ELEMENT_NODE) continue; Element element = (Element) child; // look for properties if (element.getTagName().equals("predicates")) { // re-create properties predicates = reconstitutePredicates(element); } } } private List<Condition> reconstitutePredicates(Element element) { List<Condition> rv = new ArrayList<Condition>(); try { Condition aPredicate = null; NodeList children = element.getChildNodes(); final int length = children.getLength(); for (int i = 0; i < length; i++) { Node child = children.item(i); if (child.getNodeType() != Node.ELEMENT_NODE) continue; Element predicate = (Element) child; // look for properties if (predicate.getTagName().equals("predicate")) { String className = predicate.getAttribute("class"); aPredicate = (Condition) Class.forName(className).newInstance(); ((BooleanExpression) aPredicate).setReceiver(predicate.getAttribute("receiver")); ((BooleanExpression) aPredicate).setMethod(predicate.getAttribute("method")); ((BooleanExpression) aPredicate).setOperator(predicate.getAttribute("operator")); ((BooleanExpression) aPredicate).setArgument(predicate.getAttribute("argument")); rv.add(aPredicate); } } } catch (InstantiationException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IllegalAccessException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (ClassNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } return rv; } /* (non-Javadoc) * @see org.sakaiproject.event.api.NotificationAction#set(org.sakaiproject.event.api.NotificationAction) */ public void set(NotificationAction other) { ResourceReleaseRule eOther = (ResourceReleaseRule) other; resourceId = eOther.resourceId; } /* (non-Javadoc) * @see org.sakaiproject.event.api.NotificationAction#toXml(org.w3c.dom.Element) */ public void toXml(Element el) { el.setAttribute("resourceId", this.resourceId); if (this.conj == Rule.Conjunction.OR) { el.setAttribute("conjunction", "OR"); } else if (this.conj == Rule.Conjunction.AND) { el.setAttribute("conjunction", "AND"); } Element predicates = el.getOwnerDocument().createElement("predicates"); el.appendChild(predicates); for (Predicate p : this.predicates) { Element predicateElement = el.getOwnerDocument().createElement("predicate"); predicateElement.setAttribute("class", p.getClass().getName()); predicateElement.setAttribute("receiver", ((BooleanExpression) p).getReceiver()); predicateElement.setAttribute("method", ((BooleanExpression) p).getMethod()); predicateElement.setAttribute("operator", ((BooleanExpression) p).getOperator()); Object argument = ((BooleanExpression) p).getArgument(); if (argument == null) { argument = ""; } predicateElement.setAttribute("argument", argument.toString()); predicates.appendChild(predicateElement); } } private AssignmentGrading produceAssignmentGradingFromEvent(Event event) { Double score; String userId; String[] assignmentRefParts = event.getResource().split("/"); // a score may be null after a grading event try { score = new Double(assignmentRefParts[5]); } catch (NumberFormatException e) { score = null; } userId = assignmentRefParts[4]; return produceAssignmentGrading(userId, score); } private AssignmentGrading produceAssignmentGrading(String userId, Double score) { AssignmentGrading rv = new AssignmentGrading(); rv.setUserId(userId); rv.setScore(score); return rv; } }