apache · elharo · Jul 26, 2026 · Jul 26, 2026 · elharo · Jul 26, 2026
diff --git a/src/it/MWAR-446/pom.xml b/src/it/MWAR-446/pom.xml
@@ -0,0 +1,47 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+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.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <groupId>foo.bar</groupId>
+  <artifactId>MWAR-446</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+  <packaging>war</packaging>
+  <build>
+    <plugins>
+      <plugin>
+        <groupId>@project.groupId@</groupId>
+        <artifactId>@project.artifactId@</artifactId>
+        <version>@project.version@</version>
+        <configuration>
+          <failOnMissingWebXml>false</failOnMissingWebXml>
+          <compressLibs>false</compressLibs>
+        </configuration>
+      </plugin>
+    </plugins>
+  </build>
+  <dependencies>
+    <dependency>
+      <groupId>org.codehaus.plexus</groupId>
+      <artifactId>plexus-utils</artifactId>
+      <version>@plexusUtilVersion@</version>
+    </dependency>
+  </dependencies>
+</project>
diff --git a/src/it/MWAR-446/src/main/webapp/index.html b/src/it/MWAR-446/src/main/webapp/index.html
@@ -0,0 +1,23 @@
+<!--
+
+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.
+
+-->
+<html>
+<body>Hello World</body>
+</html>
diff --git a/src/it/MWAR-446/verify.groovy b/src/it/MWAR-446/verify.groovy
@@ -0,0 +1,48 @@
+/*
+ * 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.
+ */
+
+import java.util.zip.ZipEntry
+import java.util.zip.ZipFile
+
+def warFile = new File(basedir, 'target/MWAR-446-0.0.1-SNAPSHOT.war')
+assert warFile.exists() : "WAR file should exist"
+
+def zipFile = new ZipFile(warFile)
+try {
+    def foundStoredJar = false
+    def foundDeflatedEntry = false
+
+    zipFile.entries().each { ZipEntry entry ->
+        if (entry.name.startsWith('WEB-INF/lib/') && entry.name.endsWith('.jar')) {
+            assert entry.method == ZipEntry.STORED :
+                "JAR entry ${entry.name} should be STORED (method=0) but was method=${entry.method}"
+            foundStoredJar = true
+        }
+        if (entry.name == 'index.html') {
+            assert entry.method == ZipEntry.DEFLATED :
+                "index.html should be DEFLATED (method=8) but was method=${entry.method}"
+            foundDeflatedEntry = true
+        }
+    }
+
+    assert foundStoredJar : "Should have found at least one JAR in WEB-INF/lib/"
+    assert foundDeflatedEntry : "Should have found index.html"
+} finally {
+    zipFile.close()
+}
diff --git a/src/main/java/org/apache/maven/plugins/war/AbstractWarMojo.java b/src/main/java/org/apache/maven/plugins/war/AbstractWarMojo.java
@@ -311,6 +311,18 @@ public abstract class AbstractWarMojo extends AbstractMojo {
     @Parameter(defaultValue = "true")
     private boolean recompressZippedFiles;
 
+    /**
+     * Whether dependency libraries (i.e. JAR files in {@code WEB-INF/lib/}) should be compressed (DEFLATED) when
+     * added to the WAR archive. Setting this to {@code false} will store the library JARs without compression
+     * (STORED mode), which can improve servlet container startup time since the JARs do not need to be decompressed.
+     * Note that since JAR files are already compressed, storing them without additional compression typically has
+     * negligible impact on the overall WAR file size.
+     *
+     * @since 3.5.2
+     */
+    @Parameter(defaultValue = "true")
+    private boolean compressLibs;
+
     /**
      * @since 2.4
      */
@@ -1052,6 +1064,14 @@ protected boolean isRecompressZippedFiles() {
         return recompressZippedFiles;
     }
 
+    /**
+     * @return {@link #compressLibs}
+     * @since 3.5.2
+     */
+    protected boolean isCompressLibs() {
+        return compressLibs;
+    }
+
     /**
      * @return {@link #includeEmptyDirectories}
      */

diff --git a/src/main/java/org/apache/maven/plugins/war/WarMojo.java b/src/main/java/org/apache/maven/plugins/war/WarMojo.java
@@ -43,11 +43,13 @@
 import org.apache.maven.project.MavenProjectHelper;
 import org.apache.maven.shared.filtering.MavenFileFilter;
 import org.apache.maven.shared.filtering.MavenResourcesFiltering;
+import org.codehaus.plexus.archiver.ArchiveEntry;
 import org.codehaus.plexus.archiver.ArchiverException;
 import org.codehaus.plexus.archiver.jar.ManifestException;
 import org.codehaus.plexus.archiver.manager.ArchiverManager;
 import org.codehaus.plexus.archiver.manager.NoSuchArchiverException;
 import org.codehaus.plexus.archiver.war.WarArchiver;
+import org.codehaus.plexus.archiver.zip.ConcurrentJarCreator;
 import org.codehaus.plexus.util.FileUtils;
 
 /**
@@ -200,12 +202,12 @@
        archiver.setOutputFile(warFile);

        // configure for Reproducible Builds based on outputTimestamp value
        archiver.configureReproducible(outputTimestamp);

        getLog().debug("Excluding " + Arrays.asList(getPackagingExcludes()) + " from the generated webapp archive.");
        getLog().debug("Including " + Arrays.asList(getPackagingIncludes()) + " in the generated webapp archive.");

        warArchiver.addDirectory(getWebappDirectory(), getPackagingIncludes(), getPackagingExcludes());

        final File webXmlFile = new File(getWebappDirectory(), "WEB-INF/web.xml");
        if (webXmlFile.exists()) {
@@ -386,12 +388,45 @@
 
     public WarArchiver getWarArchiver() {
         try {
-            return (WarArchiver) getArchiverManager().getArchiver("war");
+            if (isCompressLibs()) {
+                return (WarArchiver) getArchiverManager().getArchiver("war");
+            } else {
+                return new UncompressedLibsWarArchiver();
+            }
         } catch (NoSuchArchiverException e) {
             throw new IllegalStateException("Cannot find war archiver", e);
         }
     }
 
+    /**
+     * A {@link WarArchiver} subclass that stores dependency library JARs ({@code WEB-INF/lib/*.jar})
+     * in STORED mode (uncompressed) instead of DEFLATED mode, while still compressing all other entries.
+     * This improves servlet container startup time since the already-compressed JARs are not
+     * decompressed and recompressed during WAR creation and extraction.
+     */
+    private static class UncompressedLibsWarArchiver extends WarArchiver {
+
+        UncompressedLibsWarArchiver() {
+            super();
+        }
+
+        @Override
+        protected void zipFile(ArchiveEntry entry, ConcurrentJarCreator zOut, String vPath)
+                throws IOException, ArchiverException {
+            if (vPath.startsWith("WEB-INF/lib/") && !vPath.endsWith("/")) {
+                boolean original = isCompress();
+                setCompress(false);
+                try {
+                    super.zipFile(entry, zOut, vPath);
+                } finally {
+                    setCompress(original);
+                }
+            } else {
+                super.zipFile(entry, zOut, vPath);
+            }
+        }
+    }
+
     /**
      * @return {@link #projectHelper}
      */