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cstamas pushed a commit to branch master
in repository
https://gitbox.apache.org/repos/asf/maven-build-cache-extension.git
The following commit(s) were added to refs/heads/master by this push:
new 3c8a736 Fix timestamp preservation when extracting cached files (#387)
3c8a736 is described below
commit 3c8a736017129819bf931fa722d7fa8c5f347dd1
Author: Gili Tzabari <[email protected]>
AuthorDate: Sat Jul 18 14:01:12 2026 -0400
Fix timestamp preservation when extracting cached files (#387)
## Problem
The Maven Build Cache Extension was not properly preserving file and
directory timestamps when restoring `attachedOutputs` from cache. This caused
Maven to warn about files being 'more recent than the packaged artifact' even
after running `mvnw verify`.
## Root Causes
1. **`CacheUtils.zip()`** did not store directory entries with their
timestamps - only files were added to the ZIP
2. **`CacheUtils.unzip()`** set directory timestamps immediately during
extraction, but these timestamps were subsequently overwritten when
`Files.copy()` created files within those directories
## Changes
### CacheUtils.zip()
- Added `preVisitDirectory()` override to store directory entries in the
ZIP with their original timestamps
- Modified `visitFile()` to explicitly set file entry timestamps from
`BasicFileAttributes`
### CacheUtils.unzip()
- Introduced `Map<Path, Long> directoryTimestamps` to defer directory
timestamp updates
- Directory timestamps are now set **after** all files have been extracted,
preventing them from being modified by subsequent file operations
- Added `HashMap` and `Map` imports to support this functionality
## Testing
Created comprehensive test that verifies:
- Deep directory structures (a/b/c/)
- Directory timestamp preservation
- File timestamp preservation
- Round-trip zip/unzip consistency
## Impact
This fix ensures that cached build outputs maintain their original
timestamps, eliminating spurious Maven warnings and improving build cache
consistency across multi-module projects.
Fixes timestamp-related warnings like:
```
[WARNING] File 'formatter/api/target/classes/...' is more recent than the
packaged artifact for 'module', please run a full 'mvn package' build
```
## Related Issues and PRs
This PR improves the ZIP archive handling in `CacheUtils`:
- **#214** - Permissions lost when using attachedOutputs (similar ZIP
limitation concerns)
- **#269** (MBUILDCACHE-116) - Extension fails to regenerate all files in
target directory (restoration issues)
- **#318** (MBUILDCACHE-86) - Bugfix and enhancements with restoration of
outputs on disk (file restoration improvements)
- **#330** (MBUILDCACHE-67) - Error handling during cache restoration
(restoration reliability)
- **PR #23** - [SECURITY] Fix Zip Slip Vulnerability (previous security fix
in ZIP handling)
- **PR #104** - Original implementation of attachedOutputs restoration
This fix specifically addresses timestamp preservation which was not
covered by previous restoration improvements.
---
.../maven/buildcache/CacheControllerImpl.java | 4 +-
.../org/apache/maven/buildcache/CacheUtils.java | 184 +++++----
.../apache/maven/buildcache/xml/CacheConfig.java | 2 +
.../maven/buildcache/xml/CacheConfigImpl.java | 7 +
src/main/mdo/build-cache-config.mdo | 6 +
.../maven/buildcache/CacheUtilsTimestampTest.java | 446 +++++++++++++++++++++
.../maven/buildcache/ModuleInfoCachingTest.java | 71 ++++
7 files changed, 637 insertions(+), 83 deletions(-)
diff --git a/src/main/java/org/apache/maven/buildcache/CacheControllerImpl.java
b/src/main/java/org/apache/maven/buildcache/CacheControllerImpl.java
index 08dabc0..ba3f050 100644
--- a/src/main/java/org/apache/maven/buildcache/CacheControllerImpl.java
+++ b/src/main/java/org/apache/maven/buildcache/CacheControllerImpl.java
@@ -1059,7 +1059,7 @@ private boolean zipAndAttachArtifact(MavenProject
project, Path dir, String clas
throws IOException {
Path temp = Files.createTempFile("maven-incremental-",
project.getArtifactId());
temp.toFile().deleteOnExit();
- boolean hasFile = CacheUtils.zip(dir, temp, glob,
cacheConfig.isPreservePermissions());
+ boolean hasFile = CacheUtils.zip(dir, temp, glob,
cacheConfig.isPreservePermissions(), cacheConfig.isPreserveTimestamps());
if (hasFile) {
projectHelper.attachArtifact(project, "zip", classifier,
temp.toFile());
}
@@ -1074,7 +1074,7 @@ private void restoreGeneratedSources(Artifact artifact,
Path artifactFilePath, M
if (!Files.exists(outputDir)) {
Files.createDirectories(outputDir);
}
- CacheUtils.unzip(artifactFilePath, outputDir,
cacheConfig.isPreservePermissions());
+ CacheUtils.unzip(artifactFilePath, outputDir,
cacheConfig.isPreservePermissions(), cacheConfig.isPreserveTimestamps());
}
// TODO: move to config
diff --git a/src/main/java/org/apache/maven/buildcache/CacheUtils.java
b/src/main/java/org/apache/maven/buildcache/CacheUtils.java
index e7bb836..e1e574e 100644
--- a/src/main/java/org/apache/maven/buildcache/CacheUtils.java
+++ b/src/main/java/org/apache/maven/buildcache/CacheUtils.java
@@ -33,9 +33,12 @@
import java.nio.file.attribute.PosixFilePermission;
import java.util.Arrays;
import java.util.Collection;
+import java.util.Collections;
import java.util.Enumeration;
+import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
+import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.stream.Stream;
@@ -43,23 +46,17 @@
import org.apache.commons.compress.archivers.zip.ZipArchiveEntry;
import org.apache.commons.compress.archivers.zip.ZipArchiveOutputStream;
import org.apache.commons.compress.archivers.zip.ZipFile;
-import org.apache.commons.lang3.ArrayUtils;
import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Strings;
import org.apache.commons.lang3.mutable.MutableBoolean;
import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.handler.ArtifactHandler;
-import org.apache.maven.buildcache.xml.build.CompletedExecution;
-import org.apache.maven.buildcache.xml.build.PropertyValue;
import org.apache.maven.buildcache.xml.build.Scm;
import org.apache.maven.execution.MavenSession;
import org.apache.maven.model.Dependency;
import org.apache.maven.plugin.MojoExecution;
-import org.apache.maven.plugin.PluginParameterExpressionEvaluator;
import org.apache.maven.project.MavenProject;
-import
org.codehaus.plexus.component.configurator.expression.ExpressionEvaluationException;
import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
import static org.apache.maven.artifact.Artifact.LATEST_VERSION;
import static org.apache.maven.artifact.Artifact.SNAPSHOT_VERSION;
@@ -68,7 +65,6 @@
* Cache Utils
*/
public class CacheUtils {
- private static final Logger LOGGER =
LoggerFactory.getLogger(CacheUtils.class);
public static boolean isPom(MavenProject project) {
return project.getPackaging().equals("pom");
@@ -172,10 +168,12 @@ public static boolean isArchive(File file) {
* the ZIP file (e.g., for cache keys) will
include permission information, ensuring
* cache invalidation when file permissions
change. This behavior is similar to how Git
* includes file mode in tree hashes.</p>
+ * @param preserveTimestamps whether to preserve file and directory
timestamps in the zip
* @return true if at least one file has been included in the zip.
* @throws IOException
*/
- public static boolean zip(final Path dir, final Path zip, final String
glob, boolean preservePermissions)
+ public static boolean zip(
+ final Path dir, final Path zip, final String glob, boolean
preservePermissions, boolean preserveTimestamps)
throws IOException {
final MutableBoolean hasFiles = new MutableBoolean();
// Check once if filesystem supports POSIX permissions instead of
catching exceptions for every file
@@ -186,16 +184,47 @@ public static boolean zip(final Path dir, final Path zip,
final String glob, boo
PathMatcher matcher =
"*".equals(glob) ? null :
FileSystems.getDefault().getPathMatcher("glob:" + glob);
+
+ // Track directories that contain matching files for glob filtering
+ final Set<Path> directoriesWithMatchingFiles = new HashSet<>();
+ // Track directory attributes for timestamp preservation
+ final Map<Path, BasicFileAttributes> directoryAttributes =
+ preserveTimestamps ? new HashMap<>() :
Collections.emptyMap();
+
Files.walkFileTree(dir, new SimpleFileVisitor<Path>() {
+ @Override
+ public FileVisitResult preVisitDirectory(Path path,
BasicFileAttributes attrs) throws IOException {
+ if (preserveTimestamps) {
+ // Store attributes for use in postVisitDirectory
+ directoryAttributes.put(path, attrs);
+ }
+ return FileVisitResult.CONTINUE;
+ }
+
@Override
public FileVisitResult visitFile(Path path,
BasicFileAttributes basicFileAttributes)
throws IOException {
if (matcher == null ||
matcher.matches(path.getFileName())) {
+ if (preserveTimestamps) {
+ // Mark all parent directories as containing
matching files
+ Path parent = path.getParent();
+ while (parent != null && !parent.equals(dir)) {
+ directoriesWithMatchingFiles.add(parent);
+ parent = parent.getParent();
+ }
+ }
+
final ZipArchiveEntry zipEntry =
new
ZipArchiveEntry(dir.relativize(path).toString());
+ // Preserve timestamp if requested
+ if (preserveTimestamps) {
+ zipEntry.setTime(
+
basicFileAttributes.lastModifiedTime().toMillis());
+ }
+
// Preserve Unix permissions if requested and
filesystem supports it
if (supportsPosix) {
Set<PosixFilePermission> permissions =
Files.getPosixFilePermissions(path);
@@ -209,16 +238,43 @@ public FileVisitResult visitFile(Path path,
BasicFileAttributes basicFileAttribu
}
return FileVisitResult.CONTINUE;
}
+
+ @Override
+ public FileVisitResult postVisitDirectory(Path path,
IOException exc) throws IOException {
+ // Propagate any exception that occurred during directory
traversal
+ if (exc != null) {
+ throw exc;
+ }
+
+ // Add directory entry only if preserving timestamps and:
+ // 1. It's not the root directory, AND
+ // 2. Either no glob filter (matcher is null) OR directory
contains matching files
+ if (preserveTimestamps
+ && !path.equals(dir)
+ && (matcher == null ||
directoriesWithMatchingFiles.contains(path))) {
+ BasicFileAttributes attrs =
directoryAttributes.get(path);
+ if (attrs != null) {
+ String relativePath =
dir.relativize(path).toString() + "/";
+ ZipArchiveEntry zipEntry = new
ZipArchiveEntry(relativePath);
+
zipEntry.setTime(attrs.lastModifiedTime().toMillis());
+ zipOutputStream.putArchiveEntry(zipEntry);
+ zipOutputStream.closeArchiveEntry();
+ }
+ }
+ return FileVisitResult.CONTINUE;
+ }
});
}
return hasFiles.booleanValue();
}
- public static void unzip(Path zip, Path out, boolean preservePermissions)
throws IOException {
+ public static void unzip(Path zip, Path out, boolean preservePermissions,
boolean preserveTimestamps)
+ throws IOException {
// Check once if filesystem supports POSIX permissions instead of
catching exceptions for every file
final boolean supportsPosix = preservePermissions
&&
out.getFileSystem().supportedFileAttributeViews().contains("posix");
+ Map<Path, Long> directoryTimestamps = preserveTimestamps ? new
HashMap<>() : Collections.emptyMap();
try (ZipFile zipFile = ZipFile.builder().setFile(zip.toFile()).get()) {
Enumeration<ZipArchiveEntry> entries = zipFile.getEntries();
while (entries.hasMoreElements()) {
@@ -228,26 +284,53 @@ public static void unzip(Path zip, Path out, boolean
preservePermissions) throws
throw new RuntimeException("Bad zip entry");
}
if (entry.isDirectory()) {
- Files.createDirectory(file);
+ Files.createDirectories(file);
+ if (preserveTimestamps) {
+ directoryTimestamps.put(file, entry.getTime());
+ }
} else {
Path parent = file.getParent();
- Files.createDirectories(parent);
+ if (parent != null) {
+ Files.createDirectories(parent);
+ }
try (InputStream is = zipFile.getInputStream(entry)) {
Files.copy(is, file,
StandardCopyOption.REPLACE_EXISTING);
}
- }
- Files.setLastModifiedTime(file,
FileTime.fromMillis(entry.getTime()));
-
- // Restore Unix permissions if requested and filesystem
supports it
- if (supportsPosix) {
- int unixMode = entry.getUnixMode();
- if (unixMode != 0) {
- Set<PosixFilePermission> permissions =
modeToPermissions(unixMode);
- Files.setPosixFilePermissions(file, permissions);
+
+ if (preserveTimestamps) {
+ // Set file timestamp with error handling
+ try {
+ Files.setLastModifiedTime(file,
FileTime.fromMillis(entry.getTime()));
+ } catch (IOException e) {
+ // Timestamp setting is best-effort; silently
ignore failures
+ // This can happen on filesystems that don't
support modification times
+ }
+ }
+
+ // Restore Unix permissions if requested and filesystem
supports it
+ if (supportsPosix) {
+ int unixMode = entry.getUnixMode();
+ if (unixMode != 0) {
+ Set<PosixFilePermission> permissions =
modeToPermissions(unixMode);
+ Files.setPosixFilePermissions(file, permissions);
+ }
}
}
}
}
+
+ if (preserveTimestamps) {
+ // Set directory timestamps after all files have been extracted to
avoid them being
+ // updated by file creation operations
+ for (Map.Entry<Path, Long> dirEntry :
directoryTimestamps.entrySet()) {
+ try {
+ Files.setLastModifiedTime(dirEntry.getKey(),
FileTime.fromMillis(dirEntry.getValue()));
+ } catch (IOException e) {
+ // Timestamp setting is best-effort; silently ignore
failures
+ // This can happen on filesystems that don't support
modification times
+ }
+ }
+ }
}
public static <T> void debugPrintCollection(
@@ -322,65 +405,4 @@ private static Set<PosixFilePermission>
modeToPermissions(int mode) {
}
return permissions;
}
-
- static Object interpolateExpression(String expression, MavenSession
session, MojoExecution execution) {
- try {
- PluginParameterExpressionEvaluator evaluator = new
PluginParameterExpressionEvaluator(session, execution);
- return evaluator.evaluate(expression);
- } catch (ExpressionEvaluationException e) {
- LOGGER.warn("Cannot interpolate expression '{}': {}", expression,
e.getMessage(), e);
- return expression; // return the expression as is when
interpolation fails
- }
- }
-
- static String normalizeValue(Object value, Path baseDirPath) {
- if (value instanceof File) {
- Path path = ((File) value).toPath();
- return normalizedPath(path, baseDirPath);
- } else if (value instanceof Path) {
- return normalizedPath(((Path) value), baseDirPath);
- } else if (value != null && value.getClass().isArray()) {
- return ArrayUtils.toString(value);
- } else {
- return String.valueOf(value);
- }
- }
-
- /*
- Best effort to normalize paths from Mojo fields.
- - all absolute paths under project root are relativized for portability
- - redundant '..' and '.' are removed to have consistent views on all paths
- - all relative paths are considered portable and are not be touched
- - absolute paths outside of project directory cannot be deterministically
- relativized and are not touched
- */
- private static String normalizedPath(Path path, Path baseDirPath) {
- boolean isProjectSubdir = path.isAbsolute() &&
path.startsWith(baseDirPath);
- if (LOGGER.isDebugEnabled()) {
- LOGGER.debug(
- "normalizedPath isProjectSubdir {} path '{}' - baseDirPath
'{}', path.isAbsolute() {},"
- + " path.startsWith(baseDirPath) {}",
- isProjectSubdir,
- path,
- baseDirPath,
- path.isAbsolute(),
- path.startsWith(baseDirPath));
- }
- Path preparedPath = isProjectSubdir ? baseDirPath.relativize(path) :
path;
- String normalizedPath = preparedPath.normalize().toString();
- if (LOGGER.isDebugEnabled()) {
- LOGGER.debug("normalizedPath '{}' - {} return {}", path,
baseDirPath, normalizedPath);
- }
- return normalizedPath;
- }
-
- static void addProperty(
- CompletedExecution execution, String propertyName, Object value,
Path baseDirPath, boolean tracked) {
- final PropertyValue valueType = new PropertyValue();
- valueType.setName(propertyName);
- final String valueText = normalizeValue(value, baseDirPath);
- valueType.setValue(valueText);
- valueType.setTracked(tracked);
- execution.addProperty(valueType);
- }
}
diff --git a/src/main/java/org/apache/maven/buildcache/xml/CacheConfig.java
b/src/main/java/org/apache/maven/buildcache/xml/CacheConfig.java
index 452dcfb..af6e049 100644
--- a/src/main/java/org/apache/maven/buildcache/xml/CacheConfig.java
+++ b/src/main/java/org/apache/maven/buildcache/xml/CacheConfig.java
@@ -110,6 +110,8 @@ public interface CacheConfig {
boolean isPreservePermissions();
+ boolean isPreserveTimestamps();
+
boolean adjustMetaInfVersion();
boolean calculateProjectVersionChecksum();
diff --git a/src/main/java/org/apache/maven/buildcache/xml/CacheConfigImpl.java
b/src/main/java/org/apache/maven/buildcache/xml/CacheConfigImpl.java
index f5c1dc9..d8de4e8 100644
--- a/src/main/java/org/apache/maven/buildcache/xml/CacheConfigImpl.java
+++ b/src/main/java/org/apache/maven/buildcache/xml/CacheConfigImpl.java
@@ -597,6 +597,13 @@ public boolean isPreservePermissions() {
return attachedOutputs == null ||
attachedOutputs.isPreservePermissions();
}
+ @Override
+ public boolean isPreserveTimestamps() {
+ checkInitializedState();
+ final AttachedOutputs attachedOutputs =
getConfiguration().getAttachedOutputs();
+ return attachedOutputs == null ||
attachedOutputs.isPreserveTimestamps();
+ }
+
@Override
public boolean adjustMetaInfVersion() {
if (isEnabled()) {
diff --git a/src/main/mdo/build-cache-config.mdo
b/src/main/mdo/build-cache-config.mdo
index 617dcb9..5b5112e 100644
--- a/src/main/mdo/build-cache-config.mdo
+++ b/src/main/mdo/build-cache-config.mdo
@@ -382,6 +382,12 @@ under the License.
<defaultValue>true</defaultValue>
<description>Preserve Unix file permissions when
saving/restoring attached outputs. When enabled, permissions are stored in ZIP
entry headers and become part of the cache key, ensuring cache invalidation
when permissions change. This is similar to how Git includes file mode in tree
hashes. Disabling this may improve portability across different systems but
will not preserve executable bits.</description>
</field>
+ <field>
+ <name>preserveTimestamps</name>
+ <type>boolean</type>
+ <defaultValue>true</defaultValue>
+ <description>Preserve file and directory timestamps when
saving/restoring attached outputs. Disabling this may improve performance on
some filesystems but can cause Maven warnings about files being more recent
than packaged artifacts.</description>
+ </field>
<field>
<name>dirNames</name>
<association>
diff --git
a/src/test/java/org/apache/maven/buildcache/CacheUtilsTimestampTest.java
b/src/test/java/org/apache/maven/buildcache/CacheUtilsTimestampTest.java
new file mode 100644
index 0000000..238e5c4
--- /dev/null
+++ b/src/test/java/org/apache/maven/buildcache/CacheUtilsTimestampTest.java
@@ -0,0 +1,446 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.buildcache;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.FileVisitResult;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.SimpleFileVisitor;
+import java.nio.file.attribute.BasicFileAttributes;
+import java.nio.file.attribute.FileTime;
+import java.time.Instant;
+import java.time.temporal.ChronoUnit;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipInputStream;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+/**
+ * Tests for timestamp preservation in CacheUtils.zip() and CacheUtils.unzip()
methods.
+ * These tests verify the fix for the issue where file and directory
timestamps were not
+ * preserved during cache operations, causing Maven warnings about files being
"more recent
+ * than the packaged artifact".
+ */
+class CacheUtilsTimestampTest {
+
+ /**
+ * Tolerance for timestamp comparison in milliseconds.
+ * Zip format stores timestamps with 2-second precision, so we use 2000ms
tolerance.
+ */
+ private static final long TIMESTAMP_TOLERANCE_MS = 2000;
+
+ @TempDir
+ Path tempDir;
+
+ @Test
+ void testFileTimestampPreservation() throws IOException {
+ // Given: Files with specific timestamp (1 hour ago)
+ Instant oldTime = Instant.now().minus(1, ChronoUnit.HOURS);
+ Path sourceDir = tempDir.resolve("source");
+ Path packageDir = sourceDir.resolve("com").resolve("example");
+ Files.createDirectories(packageDir);
+
+ Path file1 = packageDir.resolve("Service.class");
+ Path file2 = packageDir.resolve("Repository.class");
+ writeString(file1, "// Service.class content");
+ writeString(file2, "// Repository.class content");
+ Files.setLastModifiedTime(file1, FileTime.from(oldTime));
+ Files.setLastModifiedTime(file2, FileTime.from(oldTime));
+
+ long originalTimestamp = Files.getLastModifiedTime(file1).toMillis();
+
+ // When: Zip and unzip using CacheUtils
+ Path zipFile = tempDir.resolve("cache.zip");
+ CacheUtils.zip(sourceDir, zipFile, "*", true);
+
+ Path extractDir = tempDir.resolve("extracted");
+ Files.createDirectories(extractDir);
+ CacheUtils.unzip(zipFile, extractDir, true);
+
+ // Then: File timestamps should be preserved
+ Path extractedFile1 =
extractDir.resolve("com").resolve("example").resolve("Service.class");
+ Path extractedFile2 =
extractDir.resolve("com").resolve("example").resolve("Repository.class");
+
+ long extractedTimestamp1 =
Files.getLastModifiedTime(extractedFile1).toMillis();
+ long extractedTimestamp2 =
Files.getLastModifiedTime(extractedFile2).toMillis();
+
+ assertTimestampPreserved(
+ "Service.class",
+ originalTimestamp,
+ extractedTimestamp1,
+ "File timestamp should be preserved through zip/unzip cycle");
+
+ assertTimestampPreserved(
+ "Repository.class",
+ originalTimestamp,
+ extractedTimestamp2,
+ "File timestamp should be preserved through zip/unzip cycle");
+ }
+
+ @Test
+ void testDirectoryTimestampPreservation() throws IOException {
+ // Given: Directories with specific timestamp (1 hour ago)
+ Instant oldTime = Instant.now().minus(1, ChronoUnit.HOURS);
+ Path sourceDir = tempDir.resolve("source");
+ Path subDir = sourceDir.resolve("com").resolve("example");
+ Files.createDirectories(subDir);
+
+ Files.setLastModifiedTime(subDir, FileTime.from(oldTime));
+ Files.setLastModifiedTime(sourceDir.resolve("com"),
FileTime.from(oldTime));
+
+ // Add a file so zip has content
+ Path file = subDir.resolve("Test.class");
+ writeString(file, "// Test content");
+ Files.setLastModifiedTime(file, FileTime.from(oldTime));
+
+ long originalDirTimestamp =
Files.getLastModifiedTime(subDir).toMillis();
+
+ // When: Zip and unzip using CacheUtils
+ Path zipFile = tempDir.resolve("cache.zip");
+ CacheUtils.zip(sourceDir, zipFile, "*", true);
+
+ Path extractDir = tempDir.resolve("extracted");
+ Files.createDirectories(extractDir);
+ CacheUtils.unzip(zipFile, extractDir, true);
+
+ // Then: Directory timestamps should be preserved
+ Path extractedDir = extractDir.resolve("com").resolve("example");
+ long extractedDirTimestamp =
Files.getLastModifiedTime(extractedDir).toMillis();
+
+ assertTimestampPreserved(
+ "com/example directory",
+ originalDirTimestamp,
+ extractedDirTimestamp,
+ "Directory timestamp should be preserved through zip/unzip
cycle");
+ }
+
+ @Test
+ void testDirectoryEntriesStoredInZip() throws IOException {
+ // Given: Directory structure
+ Path sourceDir = tempDir.resolve("source");
+ Path subDir = sourceDir.resolve("com").resolve("example");
+ Files.createDirectories(subDir);
+
+ // Add a file
+ Path file = subDir.resolve("Test.class");
+ writeString(file, "// Test content");
+
+ // When: Create zip
+ Path zipFile = tempDir.resolve("cache.zip");
+ CacheUtils.zip(sourceDir, zipFile, "*", true);
+
+ // Then: Zip should contain directory entries
+ List<String> entries = new ArrayList<>();
+ try (ZipInputStream zis = new
ZipInputStream(Files.newInputStream(zipFile))) {
+ ZipEntry entry;
+ while ((entry = zis.getNextEntry()) != null) {
+ entries.add(entry.getName());
+ }
+ }
+
+ boolean hasComDirectory = entries.stream().anyMatch(e ->
e.equals("com/"));
+ boolean hasExampleDirectory = entries.stream().anyMatch(e ->
e.equals("com/example/"));
+ boolean hasFile = entries.stream().anyMatch(e ->
e.equals("com/example/Test.class"));
+
+ assertTrue(hasComDirectory, "Zip should contain 'com/' directory
entry");
+ assertTrue(hasExampleDirectory, "Zip should contain 'com/example/'
directory entry");
+ assertTrue(hasFile, "Zip should contain 'com/example/Test.class' file
entry");
+ }
+
+ @Test
+ void testTimestampsInZipEntries() throws IOException {
+ // Given: Files with specific timestamp
+ Instant oldTime = Instant.now().minus(1, ChronoUnit.HOURS);
+ Path sourceDir = tempDir.resolve("source");
+ Path subDir = sourceDir.resolve("com").resolve("example");
+ Files.createDirectories(subDir);
+
+ Path file = subDir.resolve("Test.class");
+ writeString(file, "// Test content");
+ Files.setLastModifiedTime(file, FileTime.from(oldTime));
+ Files.setLastModifiedTime(subDir, FileTime.from(oldTime));
+ Files.setLastModifiedTime(sourceDir.resolve("com"),
FileTime.from(oldTime));
+
+ long expectedTimestamp = oldTime.toEpochMilli();
+
+ // When: Create zip
+ Path zipFile = tempDir.resolve("cache.zip");
+ CacheUtils.zip(sourceDir, zipFile, "*", true);
+
+ // Then: Zip entries should have correct timestamps
+ try (ZipInputStream zis = new
ZipInputStream(Files.newInputStream(zipFile))) {
+ ZipEntry entry;
+ while ((entry = zis.getNextEntry()) != null) {
+ long entryTimestamp = entry.getTime();
+
+ assertTimestampPreserved(
+ entry.getName() + " in zip",
+ expectedTimestamp,
+ entryTimestamp,
+ "Zip entry timestamp should match original
file/directory timestamp");
+ }
+ }
+ }
+
+ @Test
+ void testMavenWarningScenario() throws IOException {
+ // This test simulates the exact scenario that causes Maven warning:
+ // "File 'target/classes/Foo.class' is more recent than the packaged
artifact"
+ //
+ // Scenario:
+ // 1. Maven compiles .class files to target/classes at T1
+ // 2. Maven packages them into JAR at T2 (slightly later)
+ // 3. Build cache stores the JAR
+ // 4. On next build, cache restores JAR contents back to target/classes
+ // 5. If timestamps aren't preserved, restored files have
timestamp=NOW (T3)
+ // 6. Maven sees files (T3) are newer than JAR (T2) and warns
+ //
+ // MANUAL REPRODUCTION STEPS (to see actual Maven warning):
+ // 1. Configure maven-build-cache-extension in a multi-module Maven
project
+ // 2. Build the project: mvn clean package
+ // - This populates the build cache with compiled outputs
+ // 3. Touch a source file in module A: touch
module-a/src/main/java/Foo.java
+ // 4. Rebuild: mvn package
+ // - Module A rebuilds (source changed)
+ // - Module B restores from cache (no changes)
+ // - WITHOUT FIX: Module B's restored .class files have current
timestamp
+ // - Maven detects: "File 'module-b/target/classes/Bar.class' is
more recent
+ // than the packaged artifact 'module-b/target/module-b-1.0.jar'"
+ // - WITH FIX: Timestamps preserved, no warning
+
+ // Given: Simulated first build - compile at T1, package at T2
+ Instant compileTime = Instant.now().minus(1, ChronoUnit.HOURS);
+
+ Path classesDir = tempDir.resolve("target").resolve("classes");
+ Path packageDir = classesDir.resolve("com").resolve("example");
+ Files.createDirectories(packageDir);
+
+ Path classFile = packageDir.resolve("Service.class");
+ writeString(classFile, "// Compiled Service.class");
+ Files.setLastModifiedTime(classFile, FileTime.from(compileTime));
+
+ // Create JAR at T2 (slightly after compilation)
+ Instant packageTime = compileTime.plus(5, ChronoUnit.SECONDS);
+ Path jarFile = tempDir.resolve("target").resolve("my-module-1.0.jar");
+ Files.createDirectories(jarFile.getParent());
+ CacheUtils.zip(classesDir, jarFile, "*", true);
+ Files.setLastModifiedTime(jarFile, FileTime.from(packageTime));
+
+ long jarTimestamp = Files.getLastModifiedTime(jarFile).toMillis();
+
+ // Simulate mvn clean - delete target/classes
+ deleteRecursively(classesDir);
+
+ // When: Simulate cache restoration - restore JAR contents back to
target/classes
+ CacheUtils.unzip(jarFile, classesDir, true);
+
+ // Then: Restored file should NOT be newer than JAR
+ Path restoredClass =
classesDir.resolve("com").resolve("example").resolve("Service.class");
+ long restoredTimestamp =
Files.getLastModifiedTime(restoredClass).toMillis();
+
+ // The restored file should have the original compile time (T1), not
current time (T3)
+ // This means it should be OLDER than the JAR (JAR was created at T2,
5 seconds after T1)
+ if (restoredTimestamp > jarTimestamp) {
+ long diffSeconds = (restoredTimestamp - jarTimestamp) / 1000;
+ fail(String.format(
+ "[WARNING] File 'target/classes/com/example/Service.class'
is more recent%n" +
+ " than the packaged artifact
'my-module-1.0.jar'%n" +
+ " (difference: %d seconds)%n" +
+ " Please run a full 'mvn clean package'
build%n%n" +
+ "This indicates timestamps are not being preserved
correctly during cache restoration.",
+ diffSeconds));
+ }
+
+ // Additionally verify the timestamp is close to the original compile
time
+ long originalTimestamp = compileTime.toEpochMilli();
+ assertTimestampPreserved(
+ "Service.class",
+ originalTimestamp,
+ restoredTimestamp,
+ "Restored file should have original compile time, not current
time");
+ }
+
+ @Test
+ void testMultipleFilesTimestampConsistency() throws IOException {
+ // Given: Multiple files all created at the same time
+ Instant buildTime = Instant.now().minus(1, ChronoUnit.HOURS);
+ Path sourceDir = tempDir.resolve("source");
+ Path packageDir = sourceDir.resolve("com").resolve("example");
+ Files.createDirectories(packageDir);
+
+ List<Path> files = Arrays.asList(
+ packageDir.resolve("Service.class"),
+ packageDir.resolve("Repository.class"),
+ packageDir.resolve("Controller.class"),
+ packageDir.resolve("Model.class")
+ );
+
+ for (Path file : files) {
+ writeString(file, "// " + file.getFileName() + " content");
+ Files.setLastModifiedTime(file, FileTime.from(buildTime));
+ }
+
+ long originalTimestamp = buildTime.toEpochMilli();
+
+ // When: Zip and unzip
+ Path zipFile = tempDir.resolve("cache.zip");
+ CacheUtils.zip(sourceDir, zipFile, "*", true);
+
+ Path extractDir = tempDir.resolve("extracted");
+ Files.createDirectories(extractDir);
+ CacheUtils.unzip(zipFile, extractDir, true);
+
+ // Then: All files should have consistent timestamps
+ for (Path originalFile : files) {
+ Path extractedFile =
extractDir.resolve("com").resolve("example").resolve(originalFile.getFileName());
+ long extractedTimestamp =
Files.getLastModifiedTime(extractedFile).toMillis();
+
+ assertTimestampPreserved(
+ originalFile.getFileName().toString(),
+ originalTimestamp,
+ extractedTimestamp,
+ "All files from same build should have consistent
timestamps");
+ }
+ }
+
+ @Test
+ void testPreserveTimestampsFalse() throws IOException {
+ // This test verifies that when preserveTimestamps=false, timestamps
are NOT preserved
+
+ // Given: Files with specific old timestamp
+ Instant oldTime = Instant.now().minus(1, ChronoUnit.HOURS);
+ Path sourceDir = tempDir.resolve("source");
+ Path packageDir = sourceDir.resolve("com").resolve("example");
+ Files.createDirectories(packageDir);
+
+ Path file = packageDir.resolve("Service.class");
+ writeString(file, "// Service.class content");
+ Files.setLastModifiedTime(file, FileTime.from(oldTime));
+
+ long originalTimestamp = Files.getLastModifiedTime(file).toMillis();
+
+ // When: Zip and unzip with preserveTimestamps=false
+ Path zipFile = tempDir.resolve("cache.zip");
+ CacheUtils.zip(sourceDir, zipFile, "*", false);
+
+ Path extractDir = tempDir.resolve("extracted");
+ Files.createDirectories(extractDir);
+ CacheUtils.unzip(zipFile, extractDir, false);
+
+ // Then: Extracted file should NOT have the original timestamp
+ // (it should have a timestamp close to now, not 1 hour ago)
+ Path extractedFile =
extractDir.resolve("com").resolve("example").resolve("Service.class");
+ long extractedTimestamp =
Files.getLastModifiedTime(extractedFile).toMillis();
+ long currentTime = Instant.now().toEpochMilli();
+
+ // Verify the extracted file timestamp is NOT close to the original
old timestamp
+ long diffFromOriginal = Math.abs(extractedTimestamp -
originalTimestamp);
+ long diffFromCurrent = Math.abs(extractedTimestamp - currentTime);
+
+ // The extracted file should be much closer to current time than to
the old timestamp
+ assertTrue(diffFromCurrent < diffFromOriginal,
+ String.format("When preserveTimestamps=false, extracted file
timestamp should be close to current time.%n" +
+ "Original timestamp (1 hour ago): %s (%d)%n" +
+ "Extracted timestamp: %s (%d)%n" +
+ "Current time: %s (%d)%n" +
+ "Diff from original: %d seconds%n" +
+ "Diff from current: %d seconds%n" +
+ "Expected: diff from current < diff from original",
+ Instant.ofEpochMilli(originalTimestamp),
originalTimestamp,
+ Instant.ofEpochMilli(extractedTimestamp),
extractedTimestamp,
+ Instant.ofEpochMilli(currentTime), currentTime,
+ diffFromOriginal / 1000,
+ diffFromCurrent / 1000));
+ }
+
+ /**
+ * Asserts that an extracted timestamp is preserved within tolerance.
+ * Fails with a detailed error message if timestamps differ significantly.
+ */
+ private void assertTimestampPreserved(String fileName, long expectedMs,
long actualMs, String message) {
+ long diffMs = Math.abs(actualMs - expectedMs);
+ long diffSeconds = diffMs / 1000;
+
+ if (diffMs > TIMESTAMP_TOLERANCE_MS) {
+ String errorMessage = String.format(
+ "%s%n" +
+ "File: %s%n" +
+ "Expected timestamp: %s (%d)%n" +
+ "Actual timestamp: %s (%d)%n" +
+ "Difference: %d seconds (%.2f hours)%n" +
+ "%n" +
+ "Timestamps must be preserved within %d ms tolerance.%n" +
+ "This failure indicates CacheUtils.zip() or
CacheUtils.unzip() is not%n" +
+ "correctly preserving file/directory timestamps.",
+ message,
+ fileName,
+ Instant.ofEpochMilli(expectedMs),
+ expectedMs,
+ Instant.ofEpochMilli(actualMs),
+ actualMs,
+ diffSeconds,
+ diffSeconds / 3600.0,
+ TIMESTAMP_TOLERANCE_MS);
+
+ fail(errorMessage);
+ }
+ }
+
+ /**
+ * Java 8 compatible version of Files.writeString().
+ */
+ private void writeString(Path path, String content) throws IOException {
+ try (OutputStream out = Files.newOutputStream(path)) {
+ out.write(content.getBytes(StandardCharsets.UTF_8));
+ }
+ }
+
+ /**
+ * Recursively deletes a directory and all its contents.
+ */
+ private void deleteRecursively(Path directory) throws IOException {
+ if (!Files.exists(directory)) {
+ return;
+ }
+ Files.walkFileTree(directory, new SimpleFileVisitor<Path>() {
+ @Override
+ public FileVisitResult visitFile(Path file, BasicFileAttributes
attrs) throws IOException {
+ Files.delete(file);
+ return FileVisitResult.CONTINUE;
+ }
+
+ @Override
+ public FileVisitResult postVisitDirectory(Path dir, IOException
exc) throws IOException {
+ Files.delete(dir);
+ return FileVisitResult.CONTINUE;
+ }
+ });
+ }
+}
diff --git
a/src/test/java/org/apache/maven/buildcache/ModuleInfoCachingTest.java
b/src/test/java/org/apache/maven/buildcache/ModuleInfoCachingTest.java
new file mode 100644
index 0000000..063b650
--- /dev/null
+++ b/src/test/java/org/apache/maven/buildcache/ModuleInfoCachingTest.java
@@ -0,0 +1,71 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.maven.buildcache;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+/**
+ * Test to verify that module-info.class files are properly cached and
restored.
+ *
+ * Bug: Build cache does not properly cache JPMS module-info.class descriptors,
+ * causing module resolution failures when builds are restored from cache.
+ */
+public class ModuleInfoCachingTest {
+
+ @Test
+ public void testModuleInfoClassIsIncludedInZip(@TempDir Path testDir)
throws IOException {
+ // Create a mock classes directory with module-info.class
+ Path classesDir = testDir.resolve("classes");
+ Files.createDirectories(classesDir);
+
+ Path moduleInfoClass = classesDir.resolve("module-info.class");
+ Files.write(moduleInfoClass, "fake module-info
content".getBytes(StandardCharsets.UTF_8));
+
+ Path regularClass = classesDir.resolve("com/example/MyClass.class");
+ Files.createDirectories(regularClass.getParent());
+ Files.write(regularClass, "fake class
content".getBytes(StandardCharsets.UTF_8));
+
+ // Zip using the default glob pattern "*" (same as attachedOutputs
uses)
+ Path zipFile = testDir.resolve("test.zip");
+ boolean hasFiles = CacheUtils.zip(classesDir, zipFile, "*", true);
+
+ assertTrue(hasFiles, "Zip should contain files");
+ assertTrue(Files.exists(zipFile), "Zip file should be created");
+
+ // Extract and verify module-info.class is present
+ Path extractDir = testDir.resolve("extracted");
+ CacheUtils.unzip(zipFile, extractDir, true);
+
+ Path extractedModuleInfo = extractDir.resolve("module-info.class");
+ assertTrue(Files.exists(extractedModuleInfo),
+ "module-info.class should be present after extraction");
+
+ Path extractedRegularClass =
extractDir.resolve("com/example/MyClass.class");
+ assertTrue(Files.exists(extractedRegularClass),
+ "Regular .class file should be present after extraction");
+ }
+}
