| /* |
| * 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.ipojo.util; |
| |
| import org.apache.felix.ipojo.ConfigurationException; |
| import org.apache.felix.ipojo.metadata.Element; |
| import org.osgi.framework.BundleContext; |
| |
| import java.util.Comparator; |
| |
| /** |
| * A set of methods to simplify the parsing of dependency attributes. |
| */ |
| public class DependencyMetadataHelper { |
| |
| |
| /** |
| * Helper method parsing the comparator attribute and returning the |
| * comparator object. If the 'comparator' attribute is not set, this method |
| * returns null. If the 'comparator' attribute is set to 'osgi', this method |
| * returns the normal OSGi comparator. In other case, it tries to create |
| * an instance of the declared comparator class. |
| * |
| * @param dep the Element describing the dependency |
| * @param context the bundle context (to load the comparator class) |
| * @return the comparator object, <code>null</code> if not set. |
| * @throws org.apache.felix.ipojo.ConfigurationException the comparator class cannot be load or the |
| * comparator cannot be instantiated correctly. |
| */ |
| public static Comparator getComparator(Element dep, BundleContext context) throws ConfigurationException { |
| Comparator cmp = null; |
| String comp = dep.getAttribute("comparator"); |
| if (comp != null) { |
| if (comp.equalsIgnoreCase("osgi")) { |
| cmp = new ServiceReferenceRankingComparator(); |
| } else { |
| try { |
| Class cla = context.getBundle().loadClass(comp); |
| cmp = (Comparator) cla.newInstance(); |
| } catch (ClassNotFoundException e) { |
| throw new ConfigurationException("Cannot load a customized comparator", e); |
| } catch (IllegalAccessException e) { |
| throw new ConfigurationException("Cannot create a customized comparator", e); |
| } catch (InstantiationException e) { |
| throw new ConfigurationException("Cannot create a customized comparator", e); |
| } |
| } |
| } |
| return cmp; |
| } |
| |
| /** |
| * Loads the given specification class. |
| * |
| * @param specification the specification class name to load |
| * @param context the bundle context |
| * @return the class object for the given specification |
| * @throws org.apache.felix.ipojo.ConfigurationException if the class cannot be loaded correctly. |
| */ |
| public static Class loadSpecification(String specification, BundleContext context) throws ConfigurationException { |
| Class spec; |
| try { |
| spec = context.getBundle().loadClass(specification); |
| } catch (ClassNotFoundException e) { |
| throw new ConfigurationException("A required specification cannot be loaded : " + specification, e); |
| } |
| return spec; |
| } |
| |
| /** |
| * Helper method parsing the binding policy. |
| * If the 'policy' attribute is not set in the dependency, the method returns |
| * the 'DYNAMIC BINDING POLICY'. Accepted policy values are : dynamic, |
| * dynamic-priority and static. |
| * |
| * @param dep the Element describing the dependency |
| * @return the policy attached to this dependency |
| * @throws org.apache.felix.ipojo.ConfigurationException if an unknown binding policy was described. |
| */ |
| public static int getPolicy(Element dep) throws ConfigurationException { |
| String policy = dep.getAttribute("policy"); |
| if (policy == null || policy.equalsIgnoreCase("dynamic")) { |
| return DependencyModel.DYNAMIC_BINDING_POLICY; |
| } else if (policy.equalsIgnoreCase("dynamic-priority")) { |
| return DependencyModel.DYNAMIC_PRIORITY_BINDING_POLICY; |
| } else if (policy.equalsIgnoreCase("static")) { |
| return DependencyModel.STATIC_BINDING_POLICY; |
| } else { |
| throw new ConfigurationException("Binding policy unknown : " + policy); |
| } |
| } |
| } |