001package org.eclipse.aether.util.graph.transformer; 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.RepositoryException; 023import org.eclipse.aether.collection.DependencyGraphTransformationContext; 024import org.eclipse.aether.collection.DependencyGraphTransformer; 025import org.eclipse.aether.graph.DependencyNode; 026 027/** 028 * A dependency graph transformer that chains other transformers. 029 */ 030public final class ChainedDependencyGraphTransformer 031 implements DependencyGraphTransformer 032{ 033 034 private final DependencyGraphTransformer[] transformers; 035 036 /** 037 * Creates a new transformer that chains the specified transformers. 038 * 039 * @param transformers The transformers to chain, may be {@code null} or empty. 040 */ 041 public ChainedDependencyGraphTransformer( DependencyGraphTransformer... transformers ) 042 { 043 if ( transformers == null ) 044 { 045 this.transformers = new DependencyGraphTransformer[0]; 046 } 047 else 048 { 049 this.transformers = transformers; 050 } 051 } 052 053 /** 054 * Creates a new transformer that chains the specified transformers or simply returns one of them if the other one 055 * is {@code null}. 056 * 057 * @param transformer1 The first transformer of the chain, may be {@code null}. 058 * @param transformer2 The second transformer of the chain, may be {@code null}. 059 * @return The chained transformer or {@code null} if both input transformers are {@code null}. 060 */ 061 public static DependencyGraphTransformer newInstance( DependencyGraphTransformer transformer1, 062 DependencyGraphTransformer transformer2 ) 063 { 064 if ( transformer1 == null ) 065 { 066 return transformer2; 067 } 068 else if ( transformer2 == null ) 069 { 070 return transformer1; 071 } 072 return new ChainedDependencyGraphTransformer( transformer1, transformer2 ); 073 } 074 075 public DependencyNode transformGraph( DependencyNode node, DependencyGraphTransformationContext context ) 076 throws RepositoryException 077 { 078 for ( DependencyGraphTransformer transformer : transformers ) 079 { 080 node = transformer.transformGraph( node, context ); 081 } 082 return node; 083 } 084 085}