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.model.root;
20
21 import java.nio.file.Path;
22
23 import org.apache.maven.api.annotations.Nonnull;
24 import org.apache.maven.api.annotations.Nullable;
25
26 /**
27 * Interface used to locate the root directory for a given project.
28 *
29 * The root locator is usually looked up from the plexus container.
30 * One notable exception is the computation of the early {@code session.rootDirectory}
31 * property which happens very early. The implementation used in this case
32 * will be discovered using the JDK service mechanism.
33 *
34 * The default implementation will look for a {@code .mvn} child directory
35 * or a {@code pom.xml} containing the {@code root="true"} attribute.
36 *
37 * @see DefaultRootLocator
38 */
39 public interface RootLocator {
40
41 String UNABLE_TO_FIND_ROOT_PROJECT_MESSAGE = "Unable to find the root directory. "
42 + "Create a .mvn directory in the root directory or add the root=\"true\""
43 + " attribute on the root project's model to identify it.";
44
45 @Nonnull
46 default Path findMandatoryRoot(Path basedir) {
47 Path rootDirectory = findRoot(basedir);
48 if (rootDirectory == null) {
49 throw new IllegalStateException(getNoRootMessage());
50 }
51 return rootDirectory;
52 }
53
54 @Nullable
55 default Path findRoot(Path basedir) {
56 Path rootDirectory = basedir;
57 while (rootDirectory != null && !isRootDirectory(rootDirectory)) {
58 rootDirectory = rootDirectory.getParent();
59 }
60 return rootDirectory;
61 }
62
63 @Nonnull
64 default String getNoRootMessage() {
65 return UNABLE_TO_FIND_ROOT_PROJECT_MESSAGE;
66 }
67
68 boolean isRootDirectory(Path dir);
69 }