001package org.eclipse.aether.util.graph.traverser; 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.DependencyTraverser; 024import org.eclipse.aether.graph.Dependency; 025 026import static java.util.Objects.requireNonNull; 027 028/** 029 * A dependency traverser which always or never traverses children. 030 */ 031public final class StaticDependencyTraverser 032 implements DependencyTraverser 033{ 034 035 private final boolean traverse; 036 037 /** 038 * Creates a new traverser with the specified traversal behavior. 039 * 040 * @param traverse {@code true} to traverse all dependencies, {@code false} to never traverse. 041 */ 042 public StaticDependencyTraverser( boolean traverse ) 043 { 044 this.traverse = traverse; 045 } 046 047 public boolean traverseDependency( Dependency dependency ) 048 { 049 requireNonNull( dependency, "dependency cannot be null" ); 050 return traverse; 051 } 052 053 public DependencyTraverser deriveChildTraverser( DependencyCollectionContext context ) 054 { 055 requireNonNull( context, "context cannot be null" ); 056 return this; 057 } 058 059 @Override 060 public boolean equals( Object obj ) 061 { 062 if ( this == obj ) 063 { 064 return true; 065 } 066 else if ( null == obj || !getClass().equals( obj.getClass() ) ) 067 { 068 return false; 069 } 070 071 StaticDependencyTraverser that = (StaticDependencyTraverser) obj; 072 return traverse == that.traverse; 073 } 074 075 @Override 076 public int hashCode() 077 { 078 int hash = getClass().hashCode(); 079 hash = hash * 31 + ( traverse ? 1 : 0 ); 080 return hash; 081 } 082 083}