Merge pull request #44380 from nosan

* gh-44380:
  Register Log42J StatusListener

Closes gh-44380

spring-boot-project/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/Log4J2LoggingSystem.java

@@ -47,6 +47,7 @@
 import org.apache.logging.log4j.core.util.AuthorizationProvider;
 import org.apache.logging.log4j.core.util.NameUtil;
 import org.apache.logging.log4j.jul.Log4jBridgeHandler;
+import org.apache.logging.log4j.status.StatusConsoleListener;
 import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.PropertiesUtil;
 
@@ -93,6 +94,9 @@ public class Log4J2LoggingSystem extends AbstractLoggingSystem {
 	static final String ENVIRONMENT_KEY = Conventions.getQualifiedAttributeName(Log4J2LoggingSystem.class,
 			"environment");
 
+	static final String STATUS_LISTENER_KEY = Conventions.getQualifiedAttributeName(Log4J2LoggingSystem.class,
+			"statusListener");
+
 	private static final LogLevels<Level> LEVELS = new LogLevels<>();
 
 	static {
@@ -214,10 +218,12 @@ public void initialize(LoggingInitializationContext initializationContext, Strin
 		if (isAlreadyInitialized(loggerContext)) {
 			return;
 		}
-		resetFallbackListenerStream(StatusLogger.getLogger());
+		StatusConsoleListener listener = new StatusConsoleListener(Level.WARN);
+		StatusLogger.getLogger().registerListener(listener);
+		loggerContext.putObject(STATUS_LISTENER_KEY, listener);
 		Environment environment = initializationContext.getEnvironment();
 		if (environment != null) {
-			getLoggerContext().putObject(ENVIRONMENT_KEY, environment);
+			loggerContext.putObject(ENVIRONMENT_KEY, environment);
 			Log4J2LoggingSystem.propertySource.setEnvironment(environment);
 			PropertiesUtil.getProperties().addPropertySource(Log4J2LoggingSystem.propertySource);
 		}
@@ -226,21 +232,6 @@ public void initialize(LoggingInitializationContext initializationContext, Strin
 		markAsInitialized(loggerContext);
 	}
 
-	/**
-	 * Reset the stream used by the fallback listener to the current system out. This
-	 * allows the fallback listener to work with any captured output streams in a similar
-	 * way to the {@code follow} attribute of the {@code Console} appender.
-	 * @param statusLogger the status logger to update
-	 */
-	private void resetFallbackListenerStream(StatusLogger statusLogger) {
-		try {
-			statusLogger.getFallbackListener().setStream(System.out);
-		}
-		catch (NoSuchMethodError ex) {
-			// Ignore for older versions of Log4J
-		}
-	}
-
 	@Override
 	protected void loadDefaults(LoggingInitializationContext initializationContext, LogFile logFile) {
 		String location = getPackagedConfigFile((logFile != null) ? "log4j2-file.xml" : "log4j2.xml");
@@ -454,9 +445,14 @@ public void cleanUp() {
 		super.cleanUp();
 		LoggerContext loggerContext = getLoggerContext();
 		markAsUninitialized(loggerContext);
+		StatusConsoleListener listener = (StatusConsoleListener) getLoggerContext().getObject(STATUS_LISTENER_KEY);
+		if (listener != null) {
+			StatusLogger.getLogger().removeListener(listener);
+			loggerContext.removeObject(STATUS_LISTENER_KEY);
+		}
 		loggerContext.getConfiguration().removeFilter(FILTER);
 		Log4J2LoggingSystem.propertySource.setEnvironment(null);
-		getLoggerContext().removeObject(ENVIRONMENT_KEY);
+		loggerContext.removeObject(ENVIRONMENT_KEY);
 	}
 
 	private LoggerConfig getLogger(String name) {

spring-boot-project/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/Log4J2LoggingSystemTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2012-2024 the original author or authors.
+ * Copyright 2012-2025 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -41,6 +41,8 @@
 import org.apache.logging.log4j.core.config.plugins.util.PluginRegistry;
 import org.apache.logging.log4j.core.util.ShutdownCallbackRegistry;
 import org.apache.logging.log4j.jul.Log4jBridgeHandler;
+import org.apache.logging.log4j.status.StatusListener;
+import org.apache.logging.log4j.status.StatusLogger;
 import org.apache.logging.log4j.util.PropertiesUtil;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
@@ -469,6 +471,42 @@ void initializeAttachesEnvironmentToLoggerContext() {
 		assertThat(environment).isSameAs(this.environment);
 	}
 
+	@Test
+	void initializeRegisterStatusListenerAndAttachToLoggerContext() {
+		this.loggingSystem.beforeInitialize();
+		this.loggingSystem.initialize(this.initializationContext, null, null);
+		LoggerContext loggerContext = (LoggerContext) LogManager.getContext(false);
+		StatusListener statusListener = (StatusListener) loggerContext
+			.getObject(Log4J2LoggingSystem.STATUS_LISTENER_KEY);
+		assertThat(statusListener).isNotNull();
+		assertThat(StatusLogger.getLogger().getListeners()).contains(statusListener);
+	}
+
+	@Test
+	void statusListenerIsUpdatedUponReinitialization() {
+		this.loggingSystem.beforeInitialize();
+		this.loggingSystem.initialize(this.initializationContext, null, null);
+		// listener should be registered
+		LoggerContext loggerContext = (LoggerContext) LogManager.getContext(false);
+		StatusListener statusListener = (StatusListener) loggerContext
+			.getObject(Log4J2LoggingSystem.STATUS_LISTENER_KEY);
+		assertThat(statusListener).isNotNull();
+		assertThat(StatusLogger.getLogger().getListeners()).contains(statusListener);
+
+		this.loggingSystem.cleanUp();
+		// listener should be removed from context and StatusLogger
+		assertThat(StatusLogger.getLogger().getListeners()).doesNotContain(statusListener);
+		assertThat(loggerContext.getObject(Log4J2LoggingSystem.STATUS_LISTENER_KEY)).isNull();
+
+		// a new listener should be registered
+		this.loggingSystem.beforeInitialize();
+		this.loggingSystem.initialize(this.initializationContext, null, null);
+		StatusListener statusListener1 = (StatusListener) loggerContext
+			.getObject(Log4J2LoggingSystem.STATUS_LISTENER_KEY);
+		assertThat(statusListener1).isNotNull();
+		assertThat(StatusLogger.getLogger().getListeners()).contains(statusListener1);
+	}
+
 	@Test
 	void initializeAddsSpringEnvironmentPropertySource() {
 		this.environment.setProperty("spring", "boot");