1 package org.apache.maven.plugins.shade.mojo;
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.io.File;
23 import java.util.ArrayList;
24 import java.util.Collections;
25 import java.util.List;
26
27 /**
28 *
29 */
30 public final class RelativizePath
31 {
32 private RelativizePath()
33 {
34 //
35 }
36
37 /**
38 * relativize a pathname.
39 * @param thing Absolute File of something. (e.g., a parent pom)
40 * @param relativeTo base to relativize it do. (e.g., a pom into which a relative pathname to the 'thing' is to be
41 * installed).
42 * @return
43 */
44 static String convertToRelativePath( File thing, File relativeTo )
45 {
46 StringBuilder relativePath;
47
48 if ( thing.getParentFile().equals( relativeTo.getParentFile() ) )
49 {
50 return thing.getName(); // a very simple relative path.
51 }
52
53 List<String> thingDirectories = RelativizePath.parentDirs( thing );
54 List<String> relativeToDirectories = RelativizePath.parentDirs( relativeTo );
55
56 //Get the shortest of the two paths
57 int length = Math.min( thingDirectories.size(), relativeToDirectories.size() );
58
59 int lastCommonRoot = -1; // index of the lowest directory down from the root that the two have in common.
60 int index;
61
62 //Find common root
63 for ( index = 0; index < length; index++ )
64 {
65 if ( thingDirectories.get( index ).equals( relativeToDirectories.get( index ) ) )
66 {
67 lastCommonRoot = index;
68 }
69 else
70 {
71 break;
72 }
73 }
74 if ( lastCommonRoot != -1 )
75 { // possible on Windows or other multi-root cases.
76 // Build up the relative path
77 relativePath = new StringBuilder();
78 // add ..'s to get from the base up to the common point
79 for ( index = lastCommonRoot + 1; index < relativeToDirectories.size(); index++ )
80 {
81 relativePath.append( "../" );
82 }
83
84 // now add down from the common point to the actual 'thing' item.
85 for ( index = lastCommonRoot + 1; index < thingDirectories.size(); index++ )
86 {
87 relativePath.append( thingDirectories.get( index ) ).append( '/' );
88 }
89 relativePath.append( thing.getName() );
90 return relativePath.toString();
91 }
92 return null;
93 }
94
95 static List<String> parentDirs( File of )
96 {
97 List<String> results = new ArrayList<>();
98 for ( File p = of.getParentFile() ; p != null ; p = p.getParentFile() )
99 {
100 if ( !"".equals( p.getName() ) )
101 {
102 results.add( p.getName() );
103 }
104 }
105
106 Collections.reverse( results );
107 return results;
108 }
109 }