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 net.luminis.useradmin.mongodb; import java.util.ArrayList; import java.util.Dictionary; import java.util.Enumeration; import java.util.List; import org.apache.felix.useradmin.RoleFactory; import org.osgi.service.useradmin.Group; import org.osgi.service.useradmin.Role; import org.osgi.service.useradmin.User; import com.mongodb.BasicDBList; import com.mongodb.BasicDBObject; import com.mongodb.DBObject; import com.mongodb.MongoException; /** * Provides a helper class for (de)serializing data to/from MongoDB. */ @SuppressWarnings("unchecked") final class MongoSerializerHelper { static final String TYPE = "type"; static final String NAME = "name"; static final String PROPERTIES = "properties"; static final String CREDENTIALS = "credentials"; static final String MEMBERS = "members"; static final String REQUIRED_MEMBERS = "requiredMembers"; static final String SET = "$set"; private final RoleProvider m_roleProvider; /** * Creates a new {@link MongoSerializerHelper} instance. * * @param roleProvider the role provider to use, cannot be <code>null</code>. */ public MongoSerializerHelper(RoleProvider roleProvider) { m_roleProvider = roleProvider; } /** * Converts a given {@link DBObject} to a {@link Role} instance. * * @param object the {@link DBObject} to convert, cannot be <code>null</code>. * @return a {@link Role} instance, never <code>null</code>. */ public Role deserialize(DBObject object) { int type = ((Integer) object.get(TYPE)).intValue(); String name = (String) object.get(NAME); Role result = RoleFactory.createRole(type, name); // Read the generic properties of the role... deserializeDictionary(result.getProperties(), (DBObject) object.get(PROPERTIES)); if ((Role.GROUP == type) || (Role.USER == type)) { // This is safe, as Group extends from User... deserializeDictionary(((User) result).getCredentials(), (DBObject) object.get(CREDENTIALS)); if (Role.GROUP == type) { for (Role member : getRoles((BasicDBList) object.get(MEMBERS))) { ((Group) result).addMember(member); } for (Role member : getRoles((BasicDBList) object.get(REQUIRED_MEMBERS))) { ((Group) result).addRequiredMember(member); } } } return result; } /** * Serializes the given {@link Role} to a {@link DBObject} instance. * * @param role the {@link Role} to serialize, cannot be <code>null</code> (unchecked!). * @return a {@link DBObject} representing the given {@link Role}, never <code>null</code>. */ public DBObject serialize(Role role) { BasicDBObject data = new BasicDBObject(); int type = role.getType(); data.put(TYPE, type); data.put(NAME, role.getName()); data.put(PROPERTIES, serializeDictionary(role.getProperties())); if ((Role.GROUP == type) || (Role.USER == type)) { data.put(CREDENTIALS, serializeDictionary(((User) role).getCredentials())); if (Role.GROUP == type) { data.put(MEMBERS, getRoleNames(((Group) role).getMembers())); data.put(REQUIRED_MEMBERS, getRoleNames(((Group) role).getRequiredMembers())); } } return data; } /** * Creates a serialized version of the given {@link Role} to be used in an update statement. * * @param role the {@link Role} to update, cannot be <code>null</code>. * @return a {@link DBObject} representing an update statement for the given {@link Role}. */ public DBObject serializeUpdate(Role role) { int type = role.getType(); BasicDBObject changeSet = new BasicDBObject(); changeSet.put(PROPERTIES, serializeDictionary(role.getProperties())); if ((Role.GROUP == type) || (Role.USER == type)) { changeSet.put(CREDENTIALS, serializeDictionary(((User) role).getCredentials())); if (Role.GROUP == type) { changeSet.put(MEMBERS, getRoleNames(((Group) role).getMembers())); changeSet.put(REQUIRED_MEMBERS, getRoleNames(((Group) role).getRequiredMembers())); } } return new BasicDBObject(SET, changeSet); } /** * Deserializes the given {@link DBObject} into the given {@link Dictionary}. * * @param dictionary the dictionary to fill; * @param object the {@link DBObject} to deserialize. */ private void deserializeDictionary(Dictionary<String, Object> dictionary, DBObject object) { for (String key : object.keySet()) { dictionary.put(decodeKey(key), object.get(key)); } } /** * Finds an existing member by its name. * * @param name the name of the member to return, cannot be <code>null</code>. * @return a member instance, never <code>null</code>. * @throws MongoException in case the requested member was not found (or any other MongoDB exception). */ private Role findExistingMember(String name) { Role result = m_roleProvider.getRole(name); if (result == null) { throw new MongoException("No such role: " + name); } return result; } /** * Serializes a given array of {@link Role}s to an list for storing in a {@link DBObject}. * * @param members the {@link Role}s to serialize, cannot be <code>null</code>. * @return the "serialized" array, never <code>null</code>. */ private List<String> getRoleNames(Role[] members) { List<String> result = new ArrayList<String>(); if (members != null) { for (Role member : members) { result.add(member.getName()); } } return result; } /** * Returns all roles mentioned in the given list. * * @param list the list with role names to convert. * @return a list with {@link Role}s, never <code>null</code>. */ private List<Role> getRoles(BasicDBList list) { List<Role> result = new ArrayList<Role>(); for (int i = 0, size = list.size(); i < size; i++) { final String memberName = (String) list.get(i); result.add(findExistingMember(memberName)); } return result; } /** * Serializes a given {@link Dictionary} into a {@link DBObject}. * * @param properties the {@link Dictionary} to serialize, cannot be <code>null</code>. * @return the serialized dictionary, never <code>null</code>. */ private DBObject serializeDictionary(Dictionary<String, Object> properties) { BasicDBObject result = new BasicDBObject(); Enumeration<String> keysEnum = properties.keys(); while (keysEnum.hasMoreElements()) { String key = keysEnum.nextElement(); Object value = properties.get(key); result.append(encodeKey(key), value); } return result; } /** * Encodes a given key by replacing all '.' and '$' with their URL encoded variants. * * @param input the input to encode, cannot be <code>null</code>. * @return the encoded input, never <code>null</code>. */ private static String encodeKey(String input) { return input.replaceAll("\\.", "%2E").replaceAll("\\$", "%24"); } /** * Decodes a given key by replacing all URL encoded '.' and '$' entities with their real characters. * * @param input the input to decode, cannot be <code>null</code>. * @return the decoded input, never <code>null</code>. */ private static String decodeKey(String input) { return input.replaceAll("%2E", "\\.").replaceAll("%24", "\\$"); } }