001package org.eclipse.aether.util.filter;
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 java.util.Collection;
023import java.util.Collections;
024import java.util.LinkedHashSet;
025import java.util.List;
026import java.util.Set;
027
028import org.eclipse.aether.graph.DependencyFilter;
029import org.eclipse.aether.graph.DependencyNode;
030
031import static java.util.Objects.requireNonNull;
032
033/**
034 * A dependency filter that combines zero or more other filters using a logical {@code AND}. The resulting filter
035 * accepts a given dependency node if and only if all constituent filters accept it.
036 */
037public final class AndDependencyFilter
038    implements DependencyFilter
039{
040
041    private final Set<DependencyFilter> filters = new LinkedHashSet<>();
042
043    /**
044     * Creates a new filter from the specified filters. Prefer {@link #newInstance(DependencyFilter, DependencyFilter)}
045     * if any of the input filters might be {@code null}.
046     * 
047     * @param filters The filters to combine, may be {@code null} but must not contain {@code null} elements.
048     */
049    public AndDependencyFilter( DependencyFilter... filters )
050    {
051        if ( filters != null )
052        {
053            Collections.addAll( this.filters, filters );
054        }
055    }
056
057    /**
058     * Creates a new filter from the specified filters.
059     * 
060     * @param filters The filters to combine, may be {@code null} but must not contain {@code null} elements.
061     */
062    public AndDependencyFilter( Collection<DependencyFilter> filters )
063    {
064        if ( filters != null )
065        {
066            this.filters.addAll( filters );
067        }
068    }
069
070    /**
071     * Creates a new filter from the specified filters.
072     * 
073     * @param filter1 The first filter to combine, may be {@code null}.
074     * @param filter2 The second filter to combine, may be {@code null}.
075     * @return The combined filter or {@code null} if both filter were {@code null}.
076     */
077    public static DependencyFilter newInstance( DependencyFilter filter1, DependencyFilter filter2 )
078    {
079        if ( filter1 == null )
080        {
081            return filter2;
082        }
083        else if ( filter2 == null )
084        {
085            return filter1;
086        }
087        return new AndDependencyFilter( filter1, filter2 );
088    }
089
090    public boolean accept( DependencyNode node, List<DependencyNode> parents )
091    {
092        requireNonNull( node, "node cannot be null" );
093        requireNonNull( parents, "parents cannot be null" );
094        for ( DependencyFilter filter : filters )
095        {
096            if ( !filter.accept( node, parents ) )
097            {
098                return false;
099            }
100        }
101        return true;
102    }
103
104    @Override
105    public boolean equals( Object obj )
106    {
107        if ( this == obj )
108        {
109            return true;
110        }
111
112        if ( obj == null || !getClass().equals( obj.getClass() ) )
113        {
114            return false;
115        }
116
117        AndDependencyFilter that = (AndDependencyFilter) obj;
118
119        return this.filters.equals( that.filters );
120    }
121
122    @Override
123    public int hashCode()
124    {
125        int hash = getClass().hashCode();
126        hash = hash * 31 + filters.hashCode();
127        return hash;
128    }
129
130}