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.nio.file.Path;
22 import java.nio.file.attribute.BasicFileAttributes;
23
24 /**
25 * A single source file, associated with the root directory from which it belong.
26 * This class contains also the output file, because this information is needed
27 * for determining whether a source file need to be recompiled.
28 *
29 * @author Martin Desruisseaux
30 */
31 final class SourceFile {
32 /**
33 * The root directory which was walked for obtaining this file.
34 */
35 final SourceDirectory directory;
36
37 /**
38 * The source file found by walking under the directory.
39 * This path is already resolved relative to {@link SourceDirectory#root}.
40 */
41 final Path file;
42
43 /**
44 * The time this file object was last modified, in milliseconds since January 1, 1970.
45 */
46 final long lastModified;
47
48 /**
49 * Whether this source has been flagged as new or modified since the last build.
50 *
51 * @see IncrementalBuildHelper#inputFileTreeChanges
52 */
53 boolean isNewOrModified;
54
55 /**
56 * Whether to ignore this file for incremental build calculation.
57 * This flag is set to {@code true} if this file matches a filter
58 * specified by {@link AbstractCompilerMojo#getIncrementalExcludes()}.
59 *
60 * <p>Note that a value of {@code true} should not prevent the {@link #isNewOrModified} flag to be
61 * set to {@code true} if a modification is detected, because we want this file to be included in
62 * compilation unit if a compilation is decided for another reason than a change of this file.</p>
63 *
64 * @see AbstractCompilerMojo#getIncrementalExcludes()
65 */
66 final boolean ignoreModification;
67
68 /**
69 * The path of the {@code .class} file, created when first requested.
70 *
71 * @see #getOutputFile(boolean)
72 */
73 private Path outputFile;
74
75 /**
76 * Creates a new source file.
77 *
78 * @param directory the root directory where the file come from
79 * @param file a source file found by walking under the directory
80 * @param attrs the source file attributes
81 * @param ignoreModification whether to ignore this file for incremental build calculation
82 */
83 SourceFile(SourceDirectory directory, Path file, BasicFileAttributes attrs, boolean ignoreModification) {
84 this.directory = directory;
85 this.file = file;
86 this.lastModified = attrs.lastModifiedTime().toMillis();
87 this.ignoreModification = ignoreModification;
88 directory.visit(file);
89 }
90
91 /**
92 * Returns the file resulting from the compilation of this source file. If the output file has been
93 * {@linkplain javax.tools.JavaFileManager#getFileForOutput obtained from the compiler}, that value
94 * if returned. Otherwise if {@code infer} is {@code true}, then the output file is inferred using
95 * {@linkplain #toOutputFile heuristic rules}.
96 *
97 * @param infer whether to allow this method to infer a default path using heuristic rules
98 * @return path to the output file, or {@code null} if unspecified and {@code infer} is {@code false}
99 */
100 Path getOutputFile(boolean infer) {
101 if (!infer) {
102 /*
103 * TODO: add a `setOutputFile(Path)` method after we clarified how to get this information from the compiler.
104 * It may be from javax.tools.JavaFileManager.getFileForOutput(...).
105 */
106 return null;
107 }
108 if (outputFile == null) {
109 outputFile = toOutputFile(
110 directory.root,
111 directory.outputDirectory,
112 file,
113 directory.fileKind.extension,
114 directory.outputFileKind.extension);
115 }
116 return outputFile;
117 }
118
119 /**
120 * Infers the path to the output file using heuristic rules.
121 * If the extension of the file is the one of {@linkplain SourceDirectory#fileKind source file kind}
122 * (usually {@code ".java"}), then it is replaced by the extension specified in {@code outputFileKind}.
123 * Otherwise the extension is left unmodified. Then, the path is made relative to the output directory.
124 *
125 * @param sourceDirectory root directory of the source file
126 * @param outputDirectory output directory of the compiled file
127 * @param file path to the source file
128 * @param extension expected extension of the source file, leading dot included
129 * @param outext extension of the output file, leading dot included
130 * @return path to the target file
131 */
132 static Path toOutputFile(Path sourceDirectory, Path outputDirectory, Path file, String extension, String outext) {
133 Path output = sourceDirectory.relativize(file);
134 String filename = file.getFileName().toString();
135 if (filename.endsWith(extension)) {
136 filename = filename.substring(0, filename.length() - extension.length());
137 filename = filename.concat(outext);
138 output = output.resolveSibling(filename);
139 }
140 return outputDirectory.resolve(output);
141 }
142
143 /**
144 * Compares the given object with this source file for equality.
145 * This method compares only the file path. Metadata such as last modification time are ignored.
146 *
147 * @param obj the object to compare
148 * @return whether the two objects have the same path and attributes
149 */
150 @Override
151 public boolean equals(Object obj) {
152 if (obj instanceof SourceFile other) {
153 return file.equals(other.file) && directory.equals(other.directory);
154 }
155 return false;
156 }
157
158 /**
159 * {@return a hash code value for this file}.
160 */
161 @Override
162 public int hashCode() {
163 return directory.hashCode() + 7 * file.hashCode();
164 }
165
166 /**
167 * {@return a string representation of this source file for debugging purposes}.
168 * This string representation is shown in Maven output if debug logs are enabled.
169 */
170 @Override
171 public String toString() {
172 return file.toString();
173 }
174 }