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.plugin.compiler;
20
21 import java.io.Closeable;
22 import java.io.IOException;
23 import java.nio.file.Files;
24 import java.nio.file.Path;
25
26 /**
27 * Helper class for removing the directory having a module name.
28 * This hack is used when the {@code --module-source-path} compiler option is used
29 * but we still want to reproduce the directory layout of Maven 3.
30 * This hack is not used when the new {@code <source>} elements is used instead.
31 *
32 * <p>The code in this class is useful only when {@link AbstractCompilerMojo#SUPPORT_LEGACY} is true.
33 * This class can be fully deleted if a future version permanently set above-cited flag to false.</p>
34 *
35 * @see CompilerMojo#directoryLevelToRemove
36 * @see ToolExecutorForTest#directoryLevelToRemove
37 */
38 final class ModuleDirectoryRemover implements Closeable {
39 /**
40 * The output directory expected by Maven 3.
41 * Example: {@code target/classes/META-INF/versions/21}.
42 */
43 private final Path mavenTarget;
44
45 /**
46 * The output directory where {@code javac} will write the classes.
47 * Example: {@code target/classes/META-INF/versions/21/org.foo.bar}.
48 */
49 private final Path javacTarget;
50
51 /**
52 * A temporary directory used as an intermediate step for avoiding name clash.
53 * Example: {@code target/classes/META-INF/versions/org.foo.bar}.
54 */
55 private final Path interTarget;
56
57 /**
58 * Temporarily renames the given output directory for matching the layout of {@code javac} output.
59 *
60 * @param outputDirectory the output directory (must exist)
61 * @param moduleName the name of the module
62 * @throws IOException if an error occurred while renaming the output directory
63 */
64 private ModuleDirectoryRemover(Path outputDirectory, String moduleName) throws IOException {
65 mavenTarget = outputDirectory;
66 interTarget = Files.move(outputDirectory, outputDirectory.resolveSibling(moduleName));
67 javacTarget = Files.createDirectory(outputDirectory).resolve(moduleName);
68 Files.move(interTarget, javacTarget);
69 }
70
71 /**
72 * Temporarily renames the given output directory for matching the layout of {@code javac} output.
73 *
74 * @param outputDirectory the output directory (must exist)
75 * @param moduleName the name of the module, or {@code null} if none
76 * @return a handler for restoring the directory to its original name, or {@code null} if there is no renaming
77 * @throws IOException if an error occurred while renaming the output directory
78 */
79 static ModuleDirectoryRemover create(Path outputDirectory, String moduleName) throws IOException {
80 return (moduleName != null) ? new ModuleDirectoryRemover(outputDirectory, moduleName) : null;
81 }
82
83 /**
84 * Restores the output directory to its original name.
85 * Note: contrarily to {@link Closeable} contract, this method is not idempotent:
86 * it cannot be executed twice. However, this is okay for the usage in this package.
87 *
88 * @throws IOException if an error occurred while renaming the output directory
89 */
90 @Override
91 public void close() throws IOException {
92 Files.move(javacTarget, interTarget);
93 Files.delete(mavenTarget);
94 Files.move(interTarget, mavenTarget);
95 }
96 }