001package org.eclipse.aether.util.graph.manager;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 * 
012 *  http://www.apache.org/licenses/LICENSE-2.0
013 * 
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import org.eclipse.aether.collection.DependencyCollectionContext;
023import org.eclipse.aether.collection.DependencyManagement;
024import org.eclipse.aether.collection.DependencyManager;
025import org.eclipse.aether.graph.Dependency;
026
027/**
028 * A dependency manager that does not do any dependency management.
029 */
030public final class NoopDependencyManager
031    implements DependencyManager
032{
033
034    /**
035     * A ready-made instance of this dependency manager which can safely be reused throughout an entire application
036     * regardless of multi-threading.
037     */
038    public static final DependencyManager INSTANCE = new NoopDependencyManager();
039
040    /**
041     * Creates a new instance of this dependency manager. Usually, {@link #INSTANCE} should be used instead.
042     */
043    public NoopDependencyManager()
044    {
045    }
046
047    public DependencyManager deriveChildManager( DependencyCollectionContext context )
048    {
049        return this;
050    }
051
052    public DependencyManagement manageDependency( Dependency dependency )
053    {
054        return null;
055    }
056
057    @Override
058    public boolean equals( Object obj )
059    {
060        if ( this == obj )
061        {
062            return true;
063        }
064        else if ( null == obj || !getClass().equals( obj.getClass() ) )
065        {
066            return false;
067        }
068        return true;
069    }
070
071    @Override
072    public int hashCode()
073    {
074        return getClass().hashCode();
075    }
076
077}