| /* |
| * Copyright (c) OSGi Alliance (2011, 2013). All Rights Reserved. |
| * |
| * Licensed 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.osgi.service.resolver; |
| |
| import java.util.ArrayList; |
| import java.util.Collection; |
| import java.util.Collections; |
| import org.osgi.resource.Requirement; |
| |
| /** |
| * Indicates failure to resolve a set of requirements. |
| * |
| * <p> |
| * If a resolution failure is caused by a missing mandatory dependency a |
| * resolver may include any requirements it has considered in the resolution |
| * exception. Clients may access this set of dependencies via the |
| * {@link #getUnresolvedRequirements()} method. |
| * |
| * <p> |
| * Resolver implementations may extend this class to provide extra state |
| * information about the reason for the resolution failure. |
| * |
| * @author $Id$ |
| */ |
| public class ResolutionException extends Exception { |
| |
| private static final long serialVersionUID = 1L; |
| |
| private final transient Collection<Requirement> unresolvedRequirements; |
| |
| /** |
| * Create a {@code ResolutionException} with the specified message, cause |
| * and unresolved requirements. |
| * |
| * @param message The message. |
| * @param cause The cause of this exception. |
| * @param unresolvedRequirements The unresolved mandatory requirements from |
| * mandatory resources or {@code null} if no unresolved requirements |
| * information is provided. |
| */ |
| public ResolutionException(String message, Throwable cause, Collection<Requirement> unresolvedRequirements) { |
| super(message, cause); |
| if ((unresolvedRequirements == null) || unresolvedRequirements.isEmpty()) { |
| this.unresolvedRequirements = null; |
| } else { |
| this.unresolvedRequirements = Collections.unmodifiableCollection(new ArrayList<Requirement>(unresolvedRequirements)); |
| } |
| } |
| |
| /** |
| * Create a {@code ResolutionException} with the specified message. |
| * |
| * @param message The message. |
| */ |
| public ResolutionException(String message) { |
| super(message); |
| unresolvedRequirements = null; |
| } |
| |
| /** |
| * Create a {@code ResolutionException} with the specified cause. |
| * |
| * @param cause The cause of this exception. |
| */ |
| public ResolutionException(Throwable cause) { |
| super(cause); |
| unresolvedRequirements = null; |
| } |
| |
| @SuppressWarnings("unchecked") |
| private static Collection<Requirement> emptyCollection() { |
| return Collections.EMPTY_LIST; |
| } |
| |
| /** |
| * Return the unresolved requirements, if any, for this exception. |
| * |
| * <p> |
| * The unresolved requirements are provided for informational purposes and |
| * the specific set of unresolved requirements that are provided after a |
| * resolve failure is not defined. |
| * |
| * @return A collection of the unresolved requirements for this exception. |
| * The returned collection may be empty if no unresolved |
| * requirements information is available. |
| */ |
| public Collection<Requirement> getUnresolvedRequirements() { |
| return (unresolvedRequirements != null) ? unresolvedRequirements : emptyCollection(); |
| } |
| } |