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()
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 * {@return whether the output file is the same as the one that we would infer from heuristic rules}
93 *
94 * <p>TODO: this is not yet implemented. We need to clarify how to get the output file information
95 * from the compiler, maybe via the {@link javax.tools.JavaFileManager#getFileForOutput} method.
96 * Then, {@link #getOutputFile} should compare that value with the inferred one and set a flag.</p>
97 */
98 boolean isStandardOutputFile() {
99 // The constants below must match the ones in `IncrementalBuild.SourceInfo`.
100 return SourceDirectory.JAVA_FILE_SUFFIX.equals(directory.fileKind.extension)
101 && SourceDirectory.CLASS_FILE_SUFFIX.equals(directory.outputFileKind.extension);
102 }
103
104 /**
105 * Returns the file resulting from the compilation of this source file. If the output file has been
106 * {@linkplain javax.tools.JavaFileManager#getFileForOutput obtained from the compiler}, that value
107 * if returned. Otherwise, output file is inferred using {@linkplain #toOutputFile heuristic rules}.
108 *
109 * @return path to the output file
110 */
111 Path getOutputFile() {
112 if (outputFile == null) {
113 outputFile = toOutputFile(
114 directory.root,
115 directory.getOutputDirectory(),
116 file,
117 directory.fileKind.extension,
118 directory.outputFileKind.extension);
119 /*
120 * TODO: compare with the file given by the compiler (if we can get that information)
121 * and set a `isStandardOutputFile` flag with the comparison result.
122 */
123 }
124 return outputFile;
125 }
126
127 /**
128 * Infers the path to the output file using heuristic rules.
129 * If the extension of the file is the one of {@linkplain SourceDirectory#fileKind source file kind}
130 * (usually {@code ".java"}), then it is replaced by the extension specified in {@code outputFileKind}.
131 * Otherwise the extension is left unmodified. Then, the path is made relative to the output directory.
132 *
133 * @param sourceDirectory root directory of the source file
134 * @param outputDirectory output directory of the compiled file
135 * @param file path to the source file
136 * @param extension expected extension of the source file, leading dot included
137 * @param outext extension of the output file, leading dot included
138 * @return path to the target file
139 */
140 static Path toOutputFile(Path sourceDirectory, Path outputDirectory, Path file, String extension, String outext) {
141 Path output = sourceDirectory.relativize(file);
142 String filename = file.getFileName().toString();
143 if (filename.endsWith(extension)) {
144 filename = filename.substring(0, filename.length() - extension.length());
145 filename = filename.concat(outext);
146 output = output.resolveSibling(filename);
147 }
148 return outputDirectory.resolve(output);
149 }
150
151 /**
152 * Compares the given object with this source file for equality.
153 * This method compares only the file path. Metadata such as last modification time are ignored.
154 *
155 * @param obj the object to compare
156 * @return whether the two objects have the same path and attributes
157 */
158 @Override
159 public boolean equals(Object obj) {
160 if (obj instanceof SourceFile other) {
161 return file.equals(other.file) && directory.equals(other.directory);
162 }
163 return false;
164 }
165
166 /**
167 * {@return a hash code value for this file}
168 */
169 @Override
170 public int hashCode() {
171 return directory.hashCode() + 7 * file.hashCode();
172 }
173
174 /**
175 * {@return a string representation of this source file for debugging purposes}
176 * This string representation is shown in Maven output if debug logs are enabled.
177 */
178 @Override
179 public String toString() {
180 return file.toString();
181 }
182 }