Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +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.dm.annotation.api; |
| 20 | |
| 21 | import java.lang.annotation.ElementType; |
| 22 | import java.lang.annotation.Retention; |
| 23 | import java.lang.annotation.RetentionPolicy; |
| 24 | import java.lang.annotation.Target; |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 25 | import java.util.Collection; |
| 26 | import java.util.Dictionary; |
| 27 | import java.util.Map; |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 28 | |
| 29 | |
| 30 | /** |
| 31 | * Annotates a method for injecting a Configuration Dependency. A configuration dependency |
| 32 | * is always required, and allows you to depend on the availability of a valid configuration |
| 33 | * for your component. This dependency requires the OSGi Configuration Admin Service. |
| 34 | * |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 35 | * The annotation can be applied on a callback method which accepts the following parameters: |
| 36 | * |
| 37 | * <p><ul> |
| 38 | * <li>callback(Dictionary) |
| 39 | * <li>callback(Component, Dictionary) |
| 40 | * <li>callback(Configuration interface) // type safe configuration |
| 41 | * <li>callback(Component, Configuration interface) // type safe configuration |
| 42 | * </ul> |
| 43 | * |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 44 | * <h3>Usage Examples</h3> |
| 45 | * |
| 46 | * <p> In the following example, the "Printer" component depends on a configuration |
| 47 | * whose PID name is "sample.PrinterConfiguration". This service will initialize |
| 48 | * its ip/port number from the provided configuration. |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 49 | * |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 50 | * <p> First, we define the configuration metadata, using standard bndtools metatatype annotations |
| 51 | * (see http://www.aqute.biz/Bnd/MetaType): |
| 52 | * |
| 53 | * <blockquote> |
| 54 | * <pre> |
| 55 | * package sample; |
| 56 | * import aQute.bnd.annotation.metatype.Meta.AD; |
| 57 | * import aQute.bnd.annotation.metatype.Meta.OCD; |
| 58 | * |
| 59 | * @OCD(description = "Declare here the Printer Configuration.") |
| 60 | * public interface PrinterConfiguration { |
| 61 | * @AD(description = "Enter the printer ip address") |
| 62 | * String ipAddress(); |
| 63 | * |
| 64 | * @AD(description = "Enter the printer address port number.") |
| 65 | * int portNumber(); |
| 66 | * } |
| 67 | * </pre> |
| 68 | * </blockquote> |
| 69 | * |
| 70 | * Next, we define our Printer service which depends on the PrinterConfiguration: |
| 71 | * |
| 72 | * <blockquote> |
| 73 | * <pre> |
| 74 | * package sample; |
| 75 | * import aQute.bnd.annotation.metatype.*; |
| 76 | * |
| 77 | * @Component |
| 78 | * public class Printer { |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 79 | * @ConfigurationDependency // Will use the fqdn of the PrinterConfiguration interface as the pid. |
| 80 | * void updated(PrinterConfiguration cnf) { |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 81 | * String ip = cnf.ipAddress(); |
| 82 | * int port = cnf.portNumber(); |
| 83 | * ... |
| 84 | * } |
| 85 | * } |
| 86 | * </pre> |
| 87 | * </blockquote> |
| 88 | * |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 89 | * In the above example, the updated callback accepts a type-safe configuration type (and its fqdn is used as the pid). |
| 90 | * <p> Configuration type is a new feature that allows you to specify an interface that is implemented |
| 91 | * by DM and such interface is then injected to your callback instead of the actual Dictionary. |
| 92 | * Using such configuration interface provides a way for creating type-safe configurations from a actual {@link Dictionary} that is |
| 93 | * normally injected by Dependency Manager. |
| 94 | * The callback accepts in argument an interface that you have to provide, and DM will inject a proxy that converts |
| 95 | * method calls from your configuration-type to lookups in the actual map or dictionary. The results of these lookups are then |
| 96 | * converted to the expected return type of the invoked configuration method.<br> |
| 97 | * As proxies are injected, no implementations of the desired configuration-type are necessary! |
| 98 | * </p> |
| 99 | * <p> |
| 100 | * The lookups performed are based on the name of the method called on the configuration type. The method names are |
| 101 | * "mangled" to the following form: <tt>[lower case letter] [any valid character]*</tt>. Method names starting with |
| 102 | * <tt>get</tt> or <tt>is</tt> (JavaBean convention) are stripped from these prefixes. For example: given a dictionary |
| 103 | * with the key <tt>"foo"</tt> can be accessed from a configuration-type using the following method names: |
| 104 | * <tt>foo()</tt>, <tt>getFoo()</tt> and <tt>isFoo()</tt>. |
| 105 | * </p> |
| 106 | * <p> |
| 107 | * The return values supported are: primitive types (or their object wrappers), strings, enums, arrays of |
| 108 | * primitives/strings, {@link Collection} types, {@link Map} types, {@link Class}es and interfaces. When an interface is |
| 109 | * returned, it is treated equally to a configuration type, that is, it is returned as a proxy. |
| 110 | * </p> |
| 111 | * <p> |
| 112 | * Arrays can be represented either as comma-separated values, optionally enclosed in square brackets. For example: |
| 113 | * <tt>[ a, b, c ]</tt> and <tt>a, b,c</tt> are both considered an array of length 3 with the values "a", "b" and "c". |
| 114 | * Alternatively, you can append the array index to the key in the dictionary to obtain the same: a dictionary with |
| 115 | * "arr.0" => "a", "arr.1" => "b", "arr.2" => "c" would result in the same array as the earlier examples. |
| 116 | * </p> |
| 117 | * <p> |
| 118 | * Maps can be represented as single string values similarly as arrays, each value consisting of both the key and value |
| 119 | * separated by a dot. Optionally, the value can be enclosed in curly brackets. Similar to array, you can use the same |
| 120 | * dot notation using the keys. For example, a dictionary with |
| 121 | * |
| 122 | * <pre>{@code "map" => "{key1.value1, key2.value2}"}</pre> |
| 123 | * |
| 124 | * and a dictionary with <p> |
| 125 | * |
| 126 | * <pre>{@code "map.key1" => "value1", "map2.key2" => "value2"}</pre> |
| 127 | * |
| 128 | * result in the same map being returned. |
| 129 | * Instead of a map, you could also define an interface with the methods <tt>getKey1()</tt> and <tt>getKey2</tt> and use |
| 130 | * that interface as return type instead of a {@link Map}. |
| 131 | * </p> |
| 132 | * <p> |
| 133 | * In case a lookup does not yield a value from the underlying map or dictionary, the following rules are applied: |
| 134 | * <ol> |
| 135 | * <li>primitive types yield their default value, as defined by the Java Specification; |
| 136 | * <li>string, {@link Class}es and enum values yield <code>null</code>; |
| 137 | * <li>for arrays, collections and maps, an empty array/collection/map is returned; |
| 138 | * <li>for other interface types that are treated as configuration type a null-object is returned. |
| 139 | * </ol> |
| 140 | * </p> |
| 141 | * |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 142 | * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> |
| 143 | */ |
| 144 | @Retention(RetentionPolicy.CLASS) |
| 145 | @Target(ElementType.METHOD) |
| 146 | public @interface ConfigurationDependency |
| 147 | { |
| 148 | /** |
| 149 | * Returns the pid for a given service (by default, the pid is the service class name). |
| 150 | * @return the pid for a given service (default = Service class name) |
| 151 | */ |
| 152 | String pid() default ""; |
| 153 | |
| 154 | /** |
| 155 | * Returns the pid from a class name. The full class name will be used as the configuration PID. |
Pierre De Rop | 40ecace | 2016-02-09 21:44:38 +0000 | [diff] [blame] | 156 | * You can use this method when you use an interface annotated with standard bndtols metatype annotations. |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 157 | * (see http://www.aqute.biz/Bnd/MetaType). |
Pierre De Rop | 1c0431f | 2016-02-06 23:28:44 +0000 | [diff] [blame] | 158 | * @return the pid class |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 159 | * @deprecated just define an updated callback which accepts as argument a configuration type. |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 160 | */ |
| 161 | Class<?> pidClass() default Object.class; |
Pierre De Rop | 9e5cdba | 2016-02-17 20:35:16 +0000 | [diff] [blame^] | 162 | |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 163 | /** |
| 164 | * Returns true if the configuration properties must be published along with the service. |
| 165 | * Any additional service properties specified directly are merged with these. |
| 166 | * @return true if configuration must be published along with the service, false if not. |
| 167 | */ |
| 168 | boolean propagate() default false; |
| 169 | |
| 170 | /** |
| 171 | * The name for this configuration dependency. When you give a name a dependency, it won't be evaluated |
| 172 | * immediately, but after the component's init method has been called, and from the init method, you can then return |
| 173 | * a map in order to dynamically configure the configuration dependency (the map has to contain a "pid" and/or "propagate" |
| 174 | * flag, prefixed with the dependency name). Then the dependency will be evaluated after the component init method, and will |
| 175 | * be injected before the start method. |
| 176 | * |
| 177 | * <p> Usage example of a Configuration dependency whose pid and propagate flag is configured dynamically from init method: |
| 178 | * |
| 179 | * <blockquote><pre> |
| 180 | * /** |
| 181 | * * A Service that dynamically defines an extra dynamic configuration dependency from its init method. |
| 182 | * */ |
| 183 | * @Component |
| 184 | * class X { |
| 185 | * private Dictionary m_config; |
| 186 | * |
| 187 | * // Inject initial Configuration (injected before any other required dependencies) |
| 188 | * @ConfigurationDependency |
| 189 | * void componentConfiguration(Dictionary config) { |
| 190 | * // you must throw an exception if the configuration is not valid |
| 191 | * m_config = config; |
| 192 | * } |
| 193 | * |
| 194 | * /** |
| 195 | * * All unnamed dependencies are injected: we can now configure our dynamic configuration whose dependency name is "global". |
| 196 | * */ |
| 197 | * @Init |
| 198 | * Map init() { |
| 199 | * return new HashMap() {{ |
| 200 | * put("global.pid", m_config.get("globalConfig.pid")); |
| 201 | * put("global.propagate", m_config.get("globalConfig.propagate")); |
| 202 | * }}; |
| 203 | * } |
| 204 | * |
| 205 | * // Injected after init, and dynamically configured by the init method. |
| 206 | * @ConfigurationDependency(name="global") |
| 207 | * void globalConfiguration(Dictionary globalConfig) { |
| 208 | * // you must throw an exception if the configuration is not valid |
| 209 | * } |
| 210 | * |
| 211 | * /** |
| 212 | * * All dependencies are injected and our service is now ready to be published. |
| 213 | * */ |
| 214 | * @Start |
| 215 | * void start() { |
| 216 | * } |
| 217 | * } |
| 218 | * </pre></blockquote> |
Pierre De Rop | 1c0431f | 2016-02-06 23:28:44 +0000 | [diff] [blame] | 219 | * @return the dependency name used to configure the dependency dynamically from init callback |
Pierre De Rop | 3a00a21 | 2015-03-01 09:27:46 +0000 | [diff] [blame] | 220 | */ |
| 221 | String name() default ""; |
| 222 | |
| 223 | /** |
| 224 | * The label used to display the tab name (or section) where the properties are displayed. Example: "Printer Service". |
| 225 | * @return The label used to display the tab name where the properties are displayed. |
| 226 | * @deprecated use standard bndtools metatype annotations instead (see http://www.aqute.biz/Bnd/MetaType) |
| 227 | */ |
| 228 | String heading() default ""; |
| 229 | |
| 230 | /** |
| 231 | * A human readable description of the PID this annotation is associated with. Example: "Configuration for the PrinterService bundle". |
| 232 | * @return A human readable description of the PID this annotation is associated with. |
| 233 | * @deprecated use standard bndtools metatype annotations instead (see http://www.aqute.biz/Bnd/MetaType) |
| 234 | */ |
| 235 | String description() default ""; |
| 236 | |
| 237 | /** |
| 238 | * The list of properties types used to expose properties in web console. |
| 239 | * @return The list of properties types used to expose properties in web console. |
| 240 | * @deprecated use standard bndtools metatype annotations instead (see http://www.aqute.biz/Bnd/MetaType) |
| 241 | */ |
| 242 | PropertyMetaData[] metadata() default {}; |
| 243 | } |