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 027import static java.util.Objects.requireNonNull; 028 029/** 030 * A dependency manager that does not do any dependency management. 031 */ 032public final class NoopDependencyManager 033 implements DependencyManager 034{ 035 036 /** 037 * A ready-made instance of this dependency manager which can safely be reused throughout an entire application 038 * regardless of multi-threading. 039 */ 040 public static final DependencyManager INSTANCE = new NoopDependencyManager(); 041 042 /** 043 * Creates a new instance of this dependency manager. Usually, {@link #INSTANCE} should be used instead. 044 */ 045 public NoopDependencyManager() 046 { 047 } 048 049 public DependencyManager deriveChildManager( DependencyCollectionContext context ) 050 { 051 requireNonNull( context, "context cannot be null" ); 052 return this; 053 } 054 055 public DependencyManagement manageDependency( Dependency dependency ) 056 { 057 requireNonNull( dependency, "dependency cannot be null" ); 058 return null; 059 } 060 061 @Override 062 public boolean equals( Object obj ) 063 { 064 if ( this == obj ) 065 { 066 return true; 067 } 068 else if ( null == obj || !getClass().equals( obj.getClass() ) ) 069 { 070 return false; 071 } 072 return true; 073 } 074 075 @Override 076 public int hashCode() 077 { 078 return getClass().hashCode(); 079 } 080 081}