Stop SpringEnvironmentPropertySource on Log4j shutdown

Author: mhalbritter

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

@@ -66,14 +66,12 @@
 import org.springframework.core.Conventions;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
-import org.springframework.core.env.ConfigurableEnvironment;
 import org.springframework.core.env.Environment;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.ResourceUtils;
 import org.springframework.util.StringUtils;
-import org.springframework.web.context.support.StandardServletEnvironment;
 
 /**
  * {@link LoggingSystem} for <a href="https://logging.apache.org/log4j/2.x/">Log4j 2</a>.
@@ -132,6 +130,8 @@ public Result filter(Logger logger, Level level, Marker marker, String msg, Obje
 
 	};
 
+	private volatile SpringEnvironmentPropertySource springEnvironmentPropertySource;
+
 	public Log4J2LoggingSystem(ClassLoader classLoader) {
 		super(classLoader);
 	}
@@ -242,7 +242,8 @@ public void initialize(LoggingInitializationContext initializationContext, Strin
 		Environment environment = initializationContext.getEnvironment();
 		if (environment != null) {
 			getLoggerContext().putObjectIfAbsent(ENVIRONMENT_KEY, environment);
-			PropertiesUtil.getProperties().addPropertySource(new SpringEnvironmentPropertySource(environment));
+			this.springEnvironmentPropertySource = new SpringEnvironmentPropertySource(environment);
+			PropertiesUtil.getProperties().addPropertySource(this.springEnvironmentPropertySource);
 		}
 		loggerContext.getConfiguration().removeFilter(FILTER);
 		super.initialize(initializationContext, configLocation, logFile);
@@ -452,9 +453,8 @@ private LevelConfiguration getLevelConfiguration(Level level) {
 	@Override
 	public Runnable getShutdownHandler() {
 		return () -> {
-			Environment environment = (Environment)getLoggerContext().getObject(ENVIRONMENT_KEY);
-			if (environment instanceof ConfigurableEnvironment configurableEnvironment) {
-				configurableEnvironment.getPropertySources().remove(StandardServletEnvironment.SERVLET_CONTEXT_PROPERTY_SOURCE_NAME);
+			if (this.springEnvironmentPropertySource != null) {
+				this.springEnvironmentPropertySource.stop();
 			}
 			getLoggerContext().stop();
 		};

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

@@ -25,9 +25,12 @@
  * Returns properties from Spring.
  *
  * @author Ralph Goers
+ * @author Moritz Halbritter
  */
 class SpringEnvironmentPropertySource implements PropertySource {
 
+	private volatile boolean stopped;
+
 	/**
 	 * System properties take precedence followed by properties in Log4j properties files.
 	 */
@@ -47,12 +50,21 @@ public int getPriority() {
 
 	@Override
 	public String getProperty(String key) {
+		if (this.stopped) {
+			return null;
+		}
 		return this.environment.getProperty(key);
 	}
 
 	@Override
 	public boolean containsProperty(String key) {
+		if (this.stopped) {
+			return false;
+		}
 		return this.environment.containsProperty(key);
 	}
 
+	void stop() {
+		this.stopped = true;
+	}
 }