Felix Meschberger | add2b4a | 2007-04-11 18:12:33 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Licensed to the Apache Software Foundation (ASF) under one |
| 3 | * or more contributor license agreements. See the NOTICE file |
| 4 | * distributed with this work for additional information |
| 5 | * regarding copyright ownership. The ASF licenses this file |
| 6 | * to you under the Apache License, Version 2.0 (the |
| 7 | * "License"); you may not use this file except in compliance |
| 8 | * with the License. You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, |
| 13 | * software distributed under the License is distributed on an |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | * KIND, either express or implied. See the License for the |
| 16 | * specific language governing permissions and limitations |
| 17 | * under the License. |
| 18 | */ |
| 19 | package org.apache.felix.cm; |
| 20 | |
| 21 | |
| 22 | import java.io.IOException; |
| 23 | import java.util.Dictionary; |
| 24 | import java.util.Enumeration; |
| 25 | |
| 26 | |
| 27 | /** |
| 28 | * The <code>PersistenceManager</code> interface defines the API to be |
| 29 | * implemented to support persisting configuration data. This interface may |
| 30 | * be implemented by bundles, which support storing configuration data in |
| 31 | * different locations. |
| 32 | * <p> |
| 33 | * The Apache Felix Configuration Admin Service bundles provides an |
| 34 | * implementation of this interface using the platform filesystem to store |
| 35 | * configuration data. |
| 36 | * <p> |
| 37 | * Implementations of this interface must support loading and storing |
| 38 | * <code>java.util.Dictionary</code> objects as defined in section 104.4.2, |
| 39 | * Configuration Properties, of the Configuration Admin Service Specification |
| 40 | * Version 1.2. |
| 41 | * <p> |
| 42 | * To make implementations of this interface available to the Configuration |
| 43 | * Admin Service they must be registered as service for this interface. The |
| 44 | * Configuration Admin Service will consider all registered services plus the |
| 45 | * default platform file system based implementation to load configuration data. |
| 46 | * To store new configuration data, the persistence manager service with the |
| 47 | * highest rank value - the <code>service.ranking</code> service property - is |
| 48 | * used. If no pesistence manager service has been registered, the platfrom |
| 49 | * file system based implementation is used. |
Felix Meschberger | add2b4a | 2007-04-11 18:12:33 +0000 | [diff] [blame] | 50 | */ |
| 51 | public interface PersistenceManager |
| 52 | { |
| 53 | |
| 54 | /** |
| 55 | * Returns <code>true</code> if a persisted <code>Dictionary</code> exists |
| 56 | * for the given <code>pid</code>. |
| 57 | * |
| 58 | * @param pid The identifier for the dictionary to test. |
| 59 | */ |
| 60 | boolean exists( String pid ); |
| 61 | |
| 62 | |
| 63 | /** |
| 64 | * Returns the <code>Dictionary</code> for the given <code>pid</code>. |
| 65 | * |
| 66 | * @param pid The identifier for the dictionary to load. |
| 67 | * |
| 68 | * @return The dictionary for the identifier. This must not be |
| 69 | * <code>null</code> but may be empty. |
| 70 | * |
| 71 | * @throws IOException If an error occurrs loading the dictionary. An |
| 72 | * <code>IOException</code> must also be thrown if no dictionary |
| 73 | * exists for the given identifier. |
| 74 | */ |
| 75 | Dictionary load( String pid ) throws IOException; |
| 76 | |
| 77 | |
| 78 | /** |
| 79 | * Returns an enumeration of all <code>Dictionary</code> objects known to |
| 80 | * this persistence manager. |
| 81 | * <p> |
| 82 | * Implementations of this method are allowed to return lazy enumerations. |
| 83 | * That is, it is allowable for the enumeration to not return a dictionary |
| 84 | * if loading it results in an error. |
| 85 | * |
| 86 | * @return A possibly empty Enumeration of all dictionaries. |
| 87 | * |
| 88 | * @throws IOException If an error occurrs getting the dictionaries. |
| 89 | */ |
| 90 | Enumeration getDictionaries() throws IOException; |
| 91 | |
| 92 | |
| 93 | /** |
| 94 | * Stores the <code>Dictionary</code> under the given <code>pid</code>. |
| 95 | * |
| 96 | * @param pid The identifier of the dictionary. |
| 97 | * @param properties The <code>Dictionary</code> to store. |
| 98 | * |
| 99 | * @throws IOException If an error occurrs storing the dictionary. If this |
| 100 | * exception is thrown, it is expected, that |
| 101 | * {@link #exists(String) exists(pid} returns <code>false</code>. |
| 102 | */ |
| 103 | void store( String pid, Dictionary properties ) throws IOException; |
| 104 | |
| 105 | |
| 106 | /** |
| 107 | * Removes the <code>Dictionary</code> for the given <code>pid</code>. If |
| 108 | * such a dictionary does not exist, this method has no effect. |
| 109 | * |
| 110 | * @param pid The identifier of the dictionary to delet. |
| 111 | * |
| 112 | * @throws IOException If an error occurrs deleting the dictionary. This |
| 113 | * exception must not be thrown if no dictionary with the given |
| 114 | * identifier exists. |
| 115 | */ |
| 116 | void delete( String pid ) throws IOException; |
| 117 | |
| 118 | } |