From b5c40510ea13aa47a3e8df92ba4f330d83ea6c9e Mon Sep 17 00:00:00 2001
From: Guillaume Nodet <gnodet@gmail.com>
Date: Tue, 23 Jun 2026 07:19:56 +0000
Subject: [PATCH 1/2] [#11683] Install JUL-to-SLF4J bridge to route
 java.util.logging through Maven logging

Adds the jul-to-slf4j bridge so that libraries using java.util.logging
(JUL) have their log output routed through SLF4J and Maven's logging
system, instead of writing directly to stderr.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 apache-maven/pom.xml                                       | 7 +++++++
 impl/maven-cli/pom.xml                                     | 4 ++++
 .../java/org/apache/maven/cling/invoker/LookupInvoker.java | 4 ++++
 pom.xml                                                    | 5 +++++
 4 files changed, 20 insertions(+)

diff --git a/apache-maven/pom.xml b/apache-maven/pom.xml
index 426bd70a67b0..dac0617fc959 100644
--- a/apache-maven/pom.xml
+++ b/apache-maven/pom.xml
@@ -70,6 +70,13 @@ under the License.
       <version>${slf4jVersion}</version>
       <scope>runtime</scope>
     </dependency>
+    <!-- bridge from java.util.logging (JUL) to SLF4J -->
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>jul-to-slf4j</artifactId>
+      <version>${slf4jVersion}</version>
+      <scope>runtime</scope>
+    </dependency>
     <dependency>
       <groupId>org.apache.maven.resolver</groupId>
       <artifactId>maven-resolver-connector-basic</artifactId>
diff --git a/impl/maven-cli/pom.xml b/impl/maven-cli/pom.xml
index 72b4554c1c92..9e9de4421e52 100644
--- a/impl/maven-cli/pom.xml
+++ b/impl/maven-cli/pom.xml
@@ -195,6 +195,10 @@ under the License.
       <groupId>org.slf4j</groupId>
       <artifactId>slf4j-api</artifactId>
     </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>jul-to-slf4j</artifactId>
+    </dependency>
     <dependency>
       <groupId>commons-cli</groupId>
       <artifactId>commons-cli</artifactId>
diff --git a/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java b/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java
index 5ec158321dbd..459f1046ef5c 100644
--- a/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java
+++ b/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java
@@ -90,6 +90,7 @@
 import org.jline.terminal.impl.AbstractPosixTerminal;
 import org.jline.terminal.spi.TerminalExt;
 import org.slf4j.LoggerFactory;
+import org.slf4j.bridge.SLF4JBridgeHandler;
 import org.slf4j.spi.LocationAwareLogger;
 
 import static java.util.Objects.requireNonNull;
@@ -428,6 +429,9 @@ protected Consumer<String> doDetermineWriter(C context) {
     }
 
     protected void activateLogging(C context) throws Exception {
+        // Route java.util.logging (JUL) through SLF4J
+        SLF4JBridgeHandler.removeHandlersForRootLogger();
+        SLF4JBridgeHandler.install();
         context.slf4jConfiguration.activate();
         if (context.options().failOnSeverity().isPresent()) {
             String logLevelThreshold = context.options().failOnSeverity().get();
diff --git a/pom.xml b/pom.xml
index fc17ca354224..f1549469538d 100644
--- a/pom.xml
+++ b/pom.xml
@@ -510,6 +510,11 @@ under the License.
         <version>${slf4jVersion}</version>
         <optional>true</optional>
       </dependency>
+      <dependency>
+        <groupId>org.slf4j</groupId>
+        <artifactId>jul-to-slf4j</artifactId>
+        <version>${slf4jVersion}</version>
+      </dependency>
       <dependency>
         <groupId>ch.qos.logback</groupId>
         <artifactId>logback-classic</artifactId>

From 989f522181f294bcf9ecc6575388739eaeb63168 Mon Sep 17 00:00:00 2001
From: Guillaume Nodet <gnodet@gmail.com>
Date: Thu, 25 Jun 2026 05:42:20 +0200
Subject: [PATCH 2/2] Guard JUL bridge installation with isInstalled() check

Avoid redundantly removing handlers and reinstalling the
SLF4JBridgeHandler on every activateLogging() call, which matters
in embedded/resident-mode scenarios where Maven is invoked multiple
times in the same JVM.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 .../java/org/apache/maven/cling/invoker/LookupInvoker.java | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java b/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java
index 459f1046ef5c..56c7fb83d7b3 100644
--- a/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java
+++ b/impl/maven-cli/src/main/java/org/apache/maven/cling/invoker/LookupInvoker.java
@@ -429,9 +429,10 @@ protected Consumer<String> doDetermineWriter(C context) {
     }
 
     protected void activateLogging(C context) throws Exception {
-        // Route java.util.logging (JUL) through SLF4J
-        SLF4JBridgeHandler.removeHandlersForRootLogger();
-        SLF4JBridgeHandler.install();
+        if (!SLF4JBridgeHandler.isInstalled()) {
+            SLF4JBridgeHandler.removeHandlersForRootLogger();
+            SLF4JBridgeHandler.install();
+        }
         context.slf4jConfiguration.activate();
         if (context.options().failOnSeverity().isPresent()) {
             String logLevelThreshold = context.options().failOnSeverity().get();