build.gradle.kts

@@ -110,6 +110,7 @@ testing.suites {
       implementation(libs.apache.maven.modelBuilder)
       implementation(libs.moshi)
       implementation(libs.moshi.kotlin)
+      implementation(libs.apache.log4j)
     }
   }
 

gradle.properties

@@ -11,7 +11,7 @@ org.gradle.parallel=true
 
 GROUP=com.gradleup.shadow
 POM_ARTIFACT_ID=shadow-gradle-plugin
-VERSION_NAME=9.0.0-beta5
+VERSION_NAME=9.0.0-beta6
 
 SONATYPE_AUTOMATIC_RELEASE=true
 SONATYPE_HOST=DEFAULT

settings.gradle.kts

@@ -15,7 +15,7 @@ pluginManagement {
 }
 
 plugins {
-  id("com.gradle.develocity") version "3.19"
+  id("com.gradle.develocity") version "3.19.1"
 }
 
 develocity {

src/docs/changes/README.md

@@ -4,6 +4,17 @@
 ## [Unreleased]
 
 
+## [v9.0.0-beta6] (2025-01-23)
+
+**Added**
+
+- Exclude `module-info.class` in Multi-Release folders by default. ([#1177](https://github.com/GradleUp/shadow/pull/1177))
+
+**Fixed**
+
+- Fix `Log4j2PluginsCacheFileTransformer` not working for merging `Log4j2Plugins.dat` files. ([#1175](https://github.com/GradleUp/shadow/pull/1175))  
+
+
 ## [v9.0.0-beta5] (2025-01-21)
 
 **Added**
@@ -478,7 +489,8 @@ Instead, use the `enableRelocation = true` and `relocationPrefix = "<new package
 
 
 
-[Unreleased]: https://github.com/GradleUp/shadow/compare/9.0.0-beta5...HEAD
+[Unreleased]: https://github.com/GradleUp/shadow/compare/9.0.0-beta6...HEAD
+[v9.0.0-beta6]: https://github.com/GradleUp/shadow/releases/tag/9.0.0-beta6
 [v9.0.0-beta5]: https://github.com/GradleUp/shadow/releases/tag/9.0.0-beta5
 [v9.0.0-beta4]: https://github.com/GradleUp/shadow/releases/tag/9.0.0-beta4
 [v9.0.0-beta3]: https://github.com/GradleUp/shadow/releases/tag/9.0.0-beta3

src/docs/configuration/merging/README.md

@@ -176,6 +176,18 @@ tasks.named('shadowJar', com.github.jengelman.gradle.plugins.shadow.tasks.Shadow
 }
 ```
 
+## Merging Log4j2 Plugin Cache Files (`Log4j2Plugins.dat`)
+
+`Log4j2PluginsCacheFileTransformer` is a `Transformer` that merges `META-INF/org/apache/logging/log4j/core/config/plugins/Log4j2Plugins.dat` plugin caches from all the jars
+containing Log4j 2.x Core components. It's a Gradle equivalent of [Log4j Plugin Descriptor Transformer](https://logging.apache.org/log4j/transform/log4j-transform-maven-shade-plugin-extensions.html#log4j-plugin-cache-transformer).
+
+```groovy
+// Merging Log4j2 Plugin Cache Files
+tasks.named('shadowJar', com.github.jengelman.gradle.plugins.shadow.tasks.ShadowJar) {
+  transform(com.github.jengelman.gradle.plugins.shadow.transformers.Log4j2PluginsCacheFileTransformer.class)
+}
+```
+
 ## Appending Text Files
 
 Generic text files can be appended together using the

src/functionalTest/kotlin/com/github/jengelman/gradle/plugins/shadow/BasePluginTest.kt

@@ -334,7 +334,7 @@ abstract class BasePluginTest {
       return transform { it.task(taskPath)?.outcome }.isNotNull().isEqualTo(expectedOutcome)
     }
 
-    private fun requireResourceAsPath(name: String): Path {
+    fun requireResourceAsPath(name: String): Path {
       val resource = this::class.java.classLoader.getResource(name)
         ?: throw NoSuchFileException("Resource $name not found.")
       return resource.toURI().toPath()

src/functionalTest/kotlin/com/github/jengelman/gradle/plugins/shadow/JavaPluginTest.kt

@@ -197,6 +197,10 @@ class JavaPluginTest : BasePluginTest() {
     }
   }
 
+  @Issue(
+    "https://github.com/GradleUp/shadow/issues/352",
+    "https://github.com/GradleUp/shadow/issues/729",
+  )
   @Test
   fun excludeSomeMetaInfFilesByDefault() {
     localRepo.module("shadow", "a", "1.0") {
@@ -207,6 +211,8 @@ class JavaPluginTest : BasePluginTest() {
         insert("META-INF/a.DSA", "DSA Signature Block")
         insert("META-INF/a.RSA", "RSA Signature Block")
         insert("META-INF/a.properties", "key=value")
+        insert("META-INF/versions/9/module-info.class", "module myModuleName {}")
+        insert("META-INF/versions/16/module-info.class", "module myModuleName {}")
         insert("module-info.class", "module myModuleName {}")
       }
     }.publish()
@@ -238,6 +244,8 @@ class JavaPluginTest : BasePluginTest() {
         "META-INF/a.SF",
         "META-INF/a.DSA",
         "META-INF/a.RSA",
+        "META-INF/versions/9/module-info.class",
+        "META-INF/versions/16/module-info.class",
         "module-info.class",
       )
     }

src/functionalTest/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/TransformersTest.kt

@@ -1,15 +1,20 @@
 package com.github.jengelman.gradle.plugins.shadow.transformers
 
+import assertk.all
 import assertk.assertThat
 import assertk.assertions.isEqualTo
+import assertk.assertions.isNotEqualTo
 import assertk.assertions.isNotNull
 import assertk.assertions.isNull
 import com.github.jengelman.gradle.plugins.shadow.util.Issue
+import com.github.jengelman.gradle.plugins.shadow.util.getStream
 import com.github.jengelman.gradle.plugins.shadow.util.isRegular
 import java.util.jar.Attributes
 import kotlin.io.path.appendText
+import kotlin.io.path.readText
 import kotlin.io.path.writeText
 import kotlin.reflect.KClass
+import org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor.PLUGIN_CACHE_FILE
 import org.junit.jupiter.api.Test
 import org.junit.jupiter.params.ParameterizedTest
 import org.junit.jupiter.params.provider.MethodSource
@@ -48,7 +53,9 @@ class TransformersTest : BaseTransformerTest() {
     commonAssertions()
   }
 
-  @Issue("https://github.com/GradleUp/shadow/issues/82")
+  @Issue(
+    "https://github.com/GradleUp/shadow/issues/82",
+  )
   @Test
   fun shadowManifestLeaksToJarManifest() {
     writeMainClass()
@@ -65,6 +72,37 @@ class TransformersTest : BaseTransformerTest() {
     assertThat(mf.mainAttributes.getValue("New-Entry")).isNull()
   }
 
+  @Issue(
+    "https://github.com/GradleUp/shadow/issues/427",
+  )
+  @Test
+  fun canMergeLog4j2PluginCacheFiles() {
+    val content = requireResourceAsPath(PLUGIN_CACHE_FILE).readText()
+    val one = buildJarOne {
+      insert(PLUGIN_CACHE_FILE, content)
+    }
+    val two = buildJarOne {
+      insert(PLUGIN_CACHE_FILE, content)
+    }
+    projectScriptPath.appendText(
+      transform<Log4j2PluginsCacheFileTransformer>(
+        shadowJarBlock = fromJar(one, two),
+      ),
+    )
+
+    run(shadowJarTask)
+
+    val actualFileBytes = outputShadowJar.use { jar ->
+      @Suppress("Since15")
+      jar.getStream(PLUGIN_CACHE_FILE).use { it.readAllBytes() }
+    }
+    assertThat(actualFileBytes.contentHashCode()).all {
+      // Hash of the original plugin cache file.
+      isNotEqualTo(-2114104185)
+      isEqualTo(1911442937)
+    }
+  }
+
   @Test
   fun canUseCustomTransformer() {
     writeMainClass()
@@ -137,7 +175,6 @@ class TransformersTest : BaseTransformerTest() {
       "" to ComponentsXmlResourceTransformer::class,
       "" to DontIncludeResourceTransformer::class,
       "{ resource.set(\"test.file\"); file.fileValue(file(\"test/some.file\")) }" to IncludeResourceTransformer::class,
-      "" to Log4j2PluginsCacheFileTransformer::class,
       "" to ManifestAppenderTransformer::class,
       "" to ManifestResourceTransformer::class,
       "{ keyTransformer = { it.toLowerCase() } }" to PropertiesFileTransformer::class,

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/ShadowJavaPlugin.kt

@@ -96,6 +96,8 @@ public abstract class ShadowJavaPlugin @Inject constructor(
         "META-INF/*.SF",
         "META-INF/*.DSA",
         "META-INF/*.RSA",
+        // module-info.class in Multi-Release folders.
+        "META-INF/versions/**/module-info.class",
         "module-info.class",
       )
     }

src/main/kotlin/com/github/jengelman/gradle/plugins/shadow/transformers/Log4j2PluginsCacheFileTransformer.kt

@@ -4,85 +4,105 @@ import com.github.jengelman.gradle.plugins.shadow.ShadowStats
 import com.github.jengelman.gradle.plugins.shadow.relocation.RelocateClassContext
 import com.github.jengelman.gradle.plugins.shadow.relocation.Relocator
 import com.github.jengelman.gradle.plugins.shadow.transformers.TransformerContext.Companion.getEntryTimestamp
-import java.io.File
 import java.net.URL
+import java.nio.file.Path
 import java.util.Collections
 import java.util.Enumeration
+import kotlin.io.path.createTempFile
+import kotlin.io.path.deleteIfExists
+import kotlin.io.path.outputStream
 import org.apache.commons.io.output.CloseShieldOutputStream
 import org.apache.logging.log4j.core.config.plugins.processor.PluginCache
-import org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor
+import org.apache.logging.log4j.core.config.plugins.processor.PluginProcessor.PLUGIN_CACHE_FILE
 import org.apache.tools.zip.ZipEntry
 import org.apache.tools.zip.ZipOutputStream
 import org.gradle.api.file.FileTreeElement
 
 /**
- * Modified from the maven equivalent to work with gradle
- *
  * Modified from [org.apache.logging.log4j.maven.plugins.shade.transformer.Log4j2PluginCacheFileTransformer.java](https://github.com/apache/logging-log4j-transform/blob/main/log4j-transform-maven-shade-plugin-extensions/src/main/java/org/apache/logging/log4j/maven/plugins/shade/transformer/Log4j2PluginCacheFileTransformer.java).
  *
  * @author Paul Nelson Baker
  * @author John Engelman
  */
 @CacheableTransformer
 public open class Log4j2PluginsCacheFileTransformer : Transformer {
-  private val temporaryFiles = mutableListOf<File>()
-  private val relocators = mutableListOf<Relocator>()
+  /**
+   * Log4j config files to share across the transformation stages.
+   */
+  private val tempFiles = mutableListOf<Path>()
+
+  /**
+   * [Relocator] instances to share across the transformation stages.
+   */
+  private val tempRelocators = mutableListOf<Relocator>()
   private var stats: ShadowStats? = null
 
   override fun canTransformResource(element: FileTreeElement): Boolean {
-    return PluginProcessor.PLUGIN_CACHE_FILE == element.name
+    return PLUGIN_CACHE_FILE == element.relativePath.pathString
   }
 
   override fun transform(context: TransformerContext) {
-    val temporaryFile = File.createTempFile("Log4j2Plugins", ".dat")
-    temporaryFile.deleteOnExit()
-    temporaryFiles.add(temporaryFile)
+    val temporaryFile = createTempFile("Log4j2Plugins", ".dat")
+    tempFiles.add(temporaryFile)
     val fos = temporaryFile.outputStream()
     context.inputStream.use {
       it.copyTo(fos)
     }
 
-    relocators.addAll(context.relocators)
+    tempRelocators.addAll(context.relocators)
 
     if (stats == null) {
       stats = context.stats
     }
   }
 
+  /**
+   * @return `true` if any dat file collected.
+   */
   override fun hasTransformedResource(): Boolean {
-    // This functionality matches the original plugin, however, I'm not clear what
-    // the exact logic is. From what I can tell temporaryFiles should be never be empty
-    // if anything has been performed.
-    return temporaryFiles.isNotEmpty() || relocators.isNotEmpty()
+    return tempFiles.isNotEmpty()
   }
 
   override fun modifyOutputStream(os: ZipOutputStream, preserveFileTimestamps: Boolean) {
-    val pluginCache = PluginCache()
-    pluginCache.loadCacheFiles(urlEnumeration)
-    relocatePlugins(pluginCache)
-    val entry = ZipEntry(PluginProcessor.PLUGIN_CACHE_FILE)
-    entry.time = getEntryTimestamp(preserveFileTimestamps, entry.time)
-    os.putNextEntry(entry)
-    pluginCache.writeCache(CloseShieldOutputStream.wrap(os))
-    temporaryFiles.clear()
+    try {
+      val aggregator = PluginCache()
+      aggregator.loadCacheFiles(urlEnumeration)
+      relocatePlugins(aggregator)
+      val entry = ZipEntry(PLUGIN_CACHE_FILE)
+      entry.time = getEntryTimestamp(preserveFileTimestamps, entry.time)
+      os.putNextEntry(entry)
+      // prevent the aggregator to close the jar output.
+      aggregator.writeCache(CloseShieldOutputStream.wrap(os))
+    } finally {
+      deleteTempFiles()
+    }
   }
 
-  private fun relocatePlugins(pluginCache: PluginCache) {
+  internal fun relocatePlugins(pluginCache: PluginCache) {
     pluginCache.allCategories.values.forEach { currentMap ->
       currentMap.values.forEach { currentPluginEntry ->
         val className = currentPluginEntry.className
         val relocateClassContext = RelocateClassContext(className, requireNotNull(stats))
-        relocators.firstOrNull { it.canRelocateClass(className) }?.let { relocator ->
+        tempRelocators.firstOrNull { it.canRelocateClass(className) }?.let { relocator ->
           // Then we perform that relocation and update the plugin entry to reflect the new value.
           currentPluginEntry.className = relocator.relocateClass(relocateClassContext)
         }
       }
     }
   }
 
+  private fun deleteTempFiles() {
+    val pathIterator = tempFiles.listIterator()
+    while (pathIterator.hasNext()) {
+      val path = pathIterator.next()
+      path.deleteIfExists()
+      pathIterator.remove()
+    }
+  }
+
   private val urlEnumeration: Enumeration<URL>
     get() {
-      val urls = temporaryFiles.map { it.toURI().toURL() }
+      val urls = tempFiles.map { it.toUri().toURL() }
       return Collections.enumeration(urls)
     }
 }