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.apache.maven.index;
20
21 import java.util.ArrayList;
22 import java.util.Collections;
23 import java.util.List;
24
25 import org.apache.maven.index.context.IndexingContext;
26
27 /**
28 * An abstract helper class for implementing ArtifactInfoFilter that actually aggregates multiple filters into one. It
29 * is up to developer to implement how will be they behave ("fail-fast", or "one-vote-enough for passing", etc).
30 *
31 * @author cstamas
32 */
33 public abstract class AbstractMultiArtifactInfoFilter implements ArtifactInfoFilter {
34 private final List<ArtifactInfoFilter> filters;
35
36 public AbstractMultiArtifactInfoFilter(final List<ArtifactInfoFilter> filters) {
37 if (filters == null || filters.isEmpty()) {
38 this.filters = null;
39 } else {
40 this.filters = new ArrayList<>(filters);
41 }
42 }
43
44 /**
45 * Returns an unmodifiable list of filters.
46 *
47 * @return
48 */
49 public List<ArtifactInfoFilter> getFilters() {
50 if (filters == null) {
51 return Collections.emptyList();
52 } else {
53 return Collections.unmodifiableList(filters);
54 }
55 }
56
57 /**
58 * The filter's implementation is: if list of filters is empty, the just accept it, otherwise consult the list of
59 * filters.
60 */
61 public boolean accepts(IndexingContext ctx, ArtifactInfo ai) {
62 if (this.filters == null) {
63 return true;
64 } else {
65 return accepts(filters, ctx, ai);
66 }
67 }
68
69 /**
70 * It is left to final implementor to implement how we want to decide using filters. This method is called only if
71 * we _have_ filters set!
72 *
73 * @param filters
74 * @param ctx
75 * @param ai
76 * @return
77 */
78 protected abstract boolean accepts(List<ArtifactInfoFilter> filters, IndexingContext ctx, ArtifactInfo ai);
79 }