Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache 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.apache.org/licenses/LICENSE-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.apache.directory.fortress.core.impl; import java.util.List; import java.util.Set; import java.util.TreeSet; import java.util.concurrent.locks.ReadWriteLock; import org.apache.commons.collections.CollectionUtils; import org.apache.commons.lang.StringUtils; import org.apache.directory.fortress.core.model.Graphable; import org.apache.directory.fortress.core.model.Hier; import org.apache.directory.fortress.core.model.OrgUnit; import org.apache.directory.fortress.core.model.Relationship; import org.jgrapht.graph.SimpleDirectedGraph; import org.slf4j.Logger; import org.slf4j.LoggerFactory; import org.apache.directory.fortress.core.GlobalIds; import org.apache.directory.fortress.core.SecurityException; import org.apache.directory.fortress.core.ValidationException; import org.apache.directory.fortress.core.util.cache.Cache; import org.apache.directory.fortress.core.util.cache.CacheMgr; /** * This utility wraps {@link HierUtil} methods to provide hierarchical functionality using the {@link org.apache.directory.fortress.core.model.OrgUnit} data set * for Permissions, {@link org.apache.directory.fortress.core.model.OrgUnit.Type#PERM}. * The {@code cn=Hierarchies, ou=OS-P} data contains Permission OU pools and within a data cache, {@link #psoCache}, contained within this class. The parent-child edges are contained in LDAP, * in {@code ftParents} attribute. The ldap data is retrieved {@link OrgUnitP#getAllDescendants(org.apache.directory.fortress.core.model.OrgUnit)} and loaded into {@code org.jgrapht.graph.SimpleDirectedGraph}. * The graph... * <ol> * <li>is stored as singleton in this class with vertices of {@code String}, and edges, as {@link org.apache.directory.fortress.core.model.Relationship}s</li> * <li>utilizes open source library, see <a href="http://www.jgrapht.org/">JGraphT</a>.</li> * <li>contains a general hierarchical data structure i.e. allows multiple inheritance with parents.</li> * <li>is a simple directed graph thus does not allow cycles.</li> * </ol> * After update is performed to ldap, the singleton is refreshed with latest info. * <p/> * Static methods on this class are intended for use by other Fortress classes, i.e. {@link DelAdminMgrImpl}. * and cannot be directly invoked by outside programs. * <p/> * This class contains singleton that can be updated but is thread safe. * <p/> * * @author <a href="mailto:dev@directory.apache.org">Apache Directory Project</a> */ final class PsoUtil { private static final Cache psoCache; private static OrgUnitP orgUnitP = new OrgUnitP(); private static final String CLS_NM = PsoUtil.class.getName(); private static final Logger LOG = LoggerFactory.getLogger(CLS_NM); /** * Initialize the Perm OU hierarchies. This will read the {@link org.apache.directory.fortress.core.model.Hier} data set from ldap and load into * the JGraphT simple digraph that referenced statically within this class. */ static { CacheMgr cacheMgr = CacheMgr.getInstance(); psoCache = cacheMgr.getCache("fortress.pso"); } /** * Recursively traverse the {@link org.apache.directory.fortress.core.model.OrgUnit} graph and return all of the descendants of a given parent {@link org.apache.directory.fortress.core.model.OrgUnit#name}. * * @param name {@link org.apache.directory.fortress.core.model.OrgUnit#name} maps on 'ftOrgUnit' object class. * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return Set of names of descendants {@link org.apache.directory.fortress.core.model.OrgUnit}s of given parent. */ static Set<String> getDescendants(String name, String contextId) { return HierUtil.getDescendants(name, getGraph(contextId)); } /** * Recursively traverse the {@link org.apache.directory.fortress.core.model.OrgUnit.Type#USER} graph and return all of the ascendants of a given child ou. * * @param name maps to logical {@link org.apache.directory.fortress.core.model.OrgUnit#name} on 'ftOrgUnit' object class. * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return Set of ou names that are ascendants of given child. */ static Set<String> getAscendants(String name, String contextId) { return HierUtil.getAscendants(name, getGraph(contextId)); } /** * Traverse one level of the {@link org.apache.directory.fortress.core.model.OrgUnit} graph and return all of the children (direct descendants) of a given parent {@link org.apache.directory.fortress.core.model.OrgUnit#name}. * * @param name {@link org.apache.directory.fortress.core.model.OrgUnit#name} maps on 'ftOrgUnit' object class. * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return Set of names of children {@link org.apache.directory.fortress.core.model.OrgUnit}s of given parent. */ public static Set<String> getChildren(String name, String contextId) { return HierUtil.getChildren(name, getGraph(contextId)); } /** * Traverse one level of the {@link org.apache.directory.fortress.core.model.OrgUnit.Type#USER} graph and return all of the parents (direct ascendants) of a given child ou. * * @param name maps to logical {@link org.apache.directory.fortress.core.model.OrgUnit#name} on 'ftOrgUnit' object class. * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return Set of ou names that are parents of given child. */ static Set<String> getParents(String name, String contextId) { return HierUtil.getParents(name, getGraph(contextId)); } /** * Recursively traverse the {@link org.apache.directory.fortress.core.model.OrgUnit.Type#PERM} graph and return number of children a given parent ou has. * * @param name maps to logical {@link org.apache.directory.fortress.core.model.OrgUnit#name} on 'ftOrgUnit' object class. * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return int value contains the number of children of a given parent ou. */ static int numChildren(String name, String contextId) { return HierUtil.numChildren(name, getGraph(contextId)); } /** * Return Set of {@link org.apache.directory.fortress.core.model.OrgUnit#name}s ascendants contained within {@link org.apache.directory.fortress.core.model.OrgUnit.Type#PERM}. * * @param ous contains list of {@link org.apache.directory.fortress.core.model.OrgUnit}s. * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return contains Set of all descendants. */ static Set<String> getInherited(List<OrgUnit> ous, String contextId) { // create Set with case insensitive comparator: Set<String> iOUs = new TreeSet<>(String.CASE_INSENSITIVE_ORDER); if (CollectionUtils.isNotEmpty(ous)) { for (OrgUnit ou : ous) { String name = ou.getName(); iOUs.add(name); Set<String> parents = HierUtil.getAscendants(name, getGraph(contextId)); if (CollectionUtils.isNotEmpty(parents)) { iOUs.addAll(parents); } } } return iOUs; } /** * This api is used by {@link DelAdminMgrImpl} to determine parentage for Permission OU processing. * It calls {@link HierUtil#validateRelationship(org.jgrapht.graph.SimpleDirectedGraph, String, String, boolean)} to evaluate three OU relationship expressions: * <ol> * <li>If child equals parent</li> * <li>If mustExist true and parent-child relationship exists</li> * <li>If mustExist false and parent-child relationship does not exist</li> * </ol> * Method will throw {@link org.apache.directory.fortress.core.ValidationException} if rule check fails meaning caller failed validation * attempt to add/remove hierarchical relationship failed. * * @param child contains {@link org.apache.directory.fortress.core.model.OrgUnit#name} of child. * @param parent contains {@link org.apache.directory.fortress.core.model.OrgUnit#name} of parent. * @param mustExist boolean is used to specify if relationship must be true. * @throws org.apache.directory.fortress.core.ValidationException * in the event it fails one of the 3 checks. */ static void validateRelationship(OrgUnit child, OrgUnit parent, boolean mustExist) throws ValidationException { HierUtil.validateRelationship(getGraph(child.getContextId()), child.getName(), parent.getName(), mustExist); } /** * This api allows synchronized access to allow updates to hierarchical relationships. * Method will update the hierarchical data set and reload the JGraphT simple digraph with latest. * * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @param relationship contains parent-child relationship targeted for addition. * @param op used to pass the ldap op {@link org.apache.directory.fortress.core.model.Hier.Op#ADD}, {@link org.apache.directory.fortress.core.model.Hier.Op#MOD}, {@link org.apache.directory.fortress.core.model.Hier.Op#REM} * @throws org.apache.directory.fortress.core.SecurityException in the event of a system error. */ static void updateHier(String contextId, Relationship relationship, Hier.Op op) throws SecurityException { HierUtil.updateHier(getGraph(contextId), relationship, op); } /** * Read this ldap record,{@code cn=Hierarchies, ou=OS-P} into this entity, {@link Hier}, before loading into this collection class,{@code org.jgrapht.graph.SimpleDirectedGraph} * using 3rd party lib, <a href="http://www.jgrapht.org/">JGraphT</a>. * * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return handle to simple digraph containing perm ou hierarchies. */ private static SimpleDirectedGraph<String, Relationship> loadGraph(String contextId) { Hier inHier = new Hier(Hier.Type.ROLE); inHier.setContextId(contextId); LOG.info("loadGraph initializing PSO context [{}]", inHier.getContextId()); List<Graphable> descendants = null; try { OrgUnit orgUnit = new OrgUnit(); orgUnit.setType(OrgUnit.Type.PERM); orgUnit.setContextId(contextId); descendants = orgUnitP.getAllDescendants(orgUnit); } catch (SecurityException se) { LOG.info("loadGraph caught SecurityException={}", se); } Hier hier = HierUtil.loadHier(contextId, descendants); SimpleDirectedGraph<String, Relationship> graph; graph = HierUtil.buildGraph(hier); psoCache.put(getKey(contextId), graph); return graph; } /** * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return handle to simple digraph containing perm ou hierarchies. */ private static SimpleDirectedGraph<String, Relationship> getGraph(String contextId) { ReadWriteLock hierLock = HierUtil.getLock(contextId, HierUtil.Type.PSO); String key = getKey(contextId); try { hierLock.readLock().lock(); SimpleDirectedGraph<String, Relationship> graph = (SimpleDirectedGraph<String, Relationship>) psoCache .get(key); if (graph == null) { try { hierLock.readLock().unlock(); hierLock.writeLock().lock(); // TODO: determine why this (code that was commented out) creates a deadlock: //graph = ( SimpleDirectedGraph<String, Relationship> ) psoCache.get( key ); //if ( graph == null ) //{ graph = loadGraph(contextId); //} hierLock.readLock().lock(); } finally { hierLock.writeLock().unlock(); } } return graph; } finally { hierLock.readLock().unlock(); } } /** * * @param contextId maps to sub-tree in DIT, for example ou=contextId, dc=jts, dc = com. * @return key to this tenant's cache entry. */ private static String getKey(String contextId) { String key = HierUtil.Type.PSO.toString(); if (StringUtils.isNotEmpty(contextId) && !contextId.equalsIgnoreCase(GlobalIds.NULL)) { key += ":" + contextId; } return key; } }