1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one 3 * or more contributor license agreements. See the NOTICE file 4 * distributed with this work for additional information 5 * regarding copyright ownership. The ASF licenses this file 6 * to you under the Apache License, Version 2.0 (the 7 * "License"); you may not use this file except in compliance 8 * with the License. You may obtain a copy of the License at 9 * 10 * http://www.apache.org/licenses/LICENSE-2.0 11 * 12 * Unless required by applicable law or agreed to in writing, 13 * software distributed under the License is distributed on an 14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 15 * KIND, either express or implied. See the License for the 16 * specific language governing permissions and limitations 17 * under the License. 18 */ 19 package org.eclipse.aether.util.artifact; 20 21 import org.eclipse.aether.artifact.ArtifactType; 22 import org.eclipse.aether.artifact.ArtifactTypeRegistry; 23 24 /** 25 * An artifact type registry which first consults its own mappings and in case of an unknown type falls back to another 26 * type registry. 27 */ 28 public final class OverlayArtifactTypeRegistry extends SimpleArtifactTypeRegistry { 29 30 private final ArtifactTypeRegistry delegate; 31 32 /** 33 * Creates a new artifact type registry with initially no registered artifact types and the specified fallback 34 * registry. Use {@link #add(ArtifactType)} to populate the registry. 35 * 36 * @param delegate The artifact type registry to fall back to, may be {@code null}. 37 */ 38 public OverlayArtifactTypeRegistry(ArtifactTypeRegistry delegate) { 39 this.delegate = delegate; 40 } 41 42 /** 43 * Adds the specified artifact type to the registry. 44 * 45 * @param type The artifact type to add, must not be {@code null}. 46 * @return This registry for chaining, never {@code null}. 47 */ 48 public OverlayArtifactTypeRegistry add(ArtifactType type) { 49 super.add(type); 50 return this; 51 } 52 53 public ArtifactType get(String typeId) { 54 ArtifactType type = super.get(typeId); 55 56 if (type == null && delegate != null) { 57 type = delegate.get(typeId); 58 } 59 60 return type; 61 } 62 }