| /* |
| * 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.felix.dm.annotation.api; |
| |
| import java.lang.annotation.ElementType; |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.RetentionPolicy; |
| import java.lang.annotation.Target; |
| |
| import org.osgi.framework.Bundle; |
| |
| /** |
| * Annotates a class or method for a bundle dependency. A bundle dependency allows you to |
| * depend on a bundle in a certain set of states (INSTALLED|RESOLVED|STARTED|...), as |
| * indicated by a state mask. You can also use a filter condition that is matched against |
| * all manifest entries. When applied on a class field, optional unavailable dependencies |
| * are injected with a NullObject. |
| * |
| * <h3>Usage Examples</h3> |
| * |
| * <p> In the following example, the "SCR" Component allows to track |
| * all bundles containing a specific "Service-Component" OSGi header, in order to load |
| * and manage all Declarative Service components specified in the SCR xml documents referenced by the header: |
| * |
| * <blockquote> |
| * <pre> |
| * @Component |
| * public class SCR { |
| * @BundleDependency(required = false, removed = "unloadServiceComponents", filter = "(Service-Component=*)", stateMask = Bundle.ACTIVE) |
| * void loadServiceComponents(Bundle b) { |
| * String descriptorPaths = (String) b.getHeaders().get("Service-Component"); |
| * // load all service component specified in the XML descriptorPaths files ... |
| * } |
| * |
| * void unloadServiceComponents(Bundle b) { |
| * // unload all service component we loaded from our "loadServiceComponents" method. |
| * } |
| * } |
| * </pre> |
| * </blockquote> |
| * |
| * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a> |
| */ |
| @Retention(RetentionPolicy.CLASS) |
| @Target(ElementType.METHOD) |
| public @interface BundleDependency |
| { |
| /** |
| * Returns the callback method to be invoked when the bundle have been updated |
| * @return the change callback |
| */ |
| String changed() default ""; |
| |
| /** |
| * Returns the callback method to invoke when the bundle is lost. |
| * @return the remove callback |
| */ |
| String removed() default ""; |
| |
| /** |
| * Returns whether the dependency is required or not. |
| * @return the required flag |
| */ |
| boolean required() default true; |
| |
| /** |
| * Returns the ldap filter dependency matching some bundle manifest headers |
| * @return the filter |
| */ |
| String filter() default ""; |
| |
| /** |
| * Returns the bundle state mask |
| * @return the state mask |
| */ |
| int stateMask() default Bundle.INSTALLED | Bundle.RESOLVED | Bundle.ACTIVE; |
| |
| /** |
| * Specifies if the manifest headers from the bundle should be propagated to the service properties. |
| * The provided service properties take precedence over the propagated bundle manifest headers. |
| * It means a bundle manifest header won't override a component service property having the same name. |
| * |
| * @return the propagation flag |
| */ |
| boolean propagate() default false; |
| |
| /** |
| * The name used when dynamically configuring this dependency from the init method. |
| * Specifying this attribute allows to dynamically configure the dependency |
| * <code>filter</code> and <code>required</code> flag from the Service's init method. |
| * All unnamed dependencies will be injected before the init() method; so from the init() method, you can |
| * then pick up whatever information needed from already injected (unnamed) dependencies, and configure dynamically |
| * your named dependencies, which will then be calculated once the init() method returns. |
| * |
| * <p> See {@link Init} annotation for an example usage of a dependency dynamically configured from the init method. |
| * @return the dependency name used to dynamically configure the dependency from the init callback |
| */ |
| String name() default ""; |
| } |