1 package org.apache.maven.index;
2
3 /*
4 * Licensed to the Apache Software Foundation (ASF) under one
5 * or more contributor license agreements. See the NOTICE file
6 * distributed with this work for additional information
7 * regarding copyright ownership. The ASF licenses this file
8 * to you under the Apache License, Version 2.0 (the
9 * "License"); you may not use this file except in compliance
10 * with the License. You may obtain a copy of the License at
11 *
12 * http://www.apache.org/licenses/LICENSE-2.0
13 *
14 * Unless required by applicable law or agreed to in writing,
15 * software distributed under the License is distributed on an
16 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 * KIND, either express or implied. See the License for the
18 * specific language governing permissions and limitations
19 * under the License.
20 */
21
22 import java.util.ArrayList;
23 import java.util.Collections;
24 import java.util.List;
25
26 import org.apache.maven.index.context.IndexingContext;
27
28 /**
29 * An abstract helper class for implementing ArtifactInfoFilter that actually aggregates multiple filters into one. It
30 * is up to developer to implement how will be they behave ("fail-fast", or "one-vote-enough for passing", etc).
31 *
32 * @author cstamas
33 */
34 public abstract class AbstractMultiArtifactInfoFilter
35 implements ArtifactInfoFilter
36 {
37 private final List<ArtifactInfoFilter> filters;
38
39 public AbstractMultiArtifactInfoFilter( final List<ArtifactInfoFilter> filters )
40 {
41 if ( filters == null || filters.isEmpty() )
42 {
43 this.filters = null;
44 }
45 else
46 {
47 this.filters = new ArrayList<ArtifactInfoFilter>( filters );
48 }
49 }
50
51 /**
52 * Returns an unmodifiable list of filters.
53 *
54 * @return
55 */
56 public List<ArtifactInfoFilter> getFilters()
57 {
58 if ( filters == null )
59 {
60 return Collections.emptyList();
61 }
62 else
63 {
64 return Collections.unmodifiableList( filters );
65 }
66 }
67
68 /**
69 * The filter's implementation is: if list of filters is empty, the just accept it, otherwise consult the list of
70 * filters.
71 */
72 public boolean accepts( IndexingContext ctx, ArtifactInfo ai )
73 {
74 if ( this.filters == null )
75 {
76 return true;
77 }
78 else
79 {
80 return accepts( filters, ctx, ai );
81 }
82 }
83
84 /**
85 * It is left to final implementor to implement how we want to decide using filters. This method is called only if
86 * we _have_ filters set!
87 *
88 * @param filters
89 * @param ctx
90 * @param ai
91 * @return
92 */
93 protected abstract boolean accepts( List<ArtifactInfoFilter> filters, IndexingContext ctx, ArtifactInfo ai );
94 }