Merge branch '2.5.x'

Closes gh-27018

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

@@ -30,13 +30,12 @@ import org.apache.logging.log4j.core.config.plugins.Plugin;
  *
  * <ol>
  * <li>Prevent logger warnings from being printed when the application first starts.
- * <li>Disable its shutdown hook
  * </ol>
  *
  * This factory is ordered last and is triggered by a {@code log4j2.springboot} classpath
  * resource (which is bundled in this jar). If the {@link Log4J2LoggingSystem} is active,
- * a custom {@link DefaultConfiguration} is returned with the expectation that the system
- * will later re-initialize Log4J2 with the correct configuration file.
+ * a {@link DefaultConfiguration} is returned with the expectation that the system will
+ * later re-initialize Log4J2 with the correct configuration file.
  *
  * @author Phillip Webb
  * @since 1.5.0
@@ -57,15 +56,7 @@ public class SpringBootConfigurationFactory extends ConfigurationFactory {
 		if (source == null || source == ConfigurationSource.NULL_SOURCE) {
 			return null;
 		}
-		return new SpringBootConfiguration();
-	}
-
-	private static final class SpringBootConfiguration extends DefaultConfiguration {
-
-		private SpringBootConfiguration() {
-			this.isShutdownHookEnabled = false;
-		}
-
+		return new DefaultConfiguration();
 	}
 
 }

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

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2012-2021 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://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.
+ */
+
+package org.springframework.boot.logging.log4j2;
+
+import java.util.Collections;
+import java.util.Map;
+
+import org.apache.logging.log4j.core.util.ShutdownCallbackRegistry;
+import org.apache.logging.log4j.util.BiConsumer;
+import org.apache.logging.log4j.util.PropertySource;
+
+/**
+ * Spring Boot {@link PropertySource} that disables Log4j2's shutdown hook.
+ *
+ * @author Andy Wilkinson
+ * @since 2.5.2
+ */
+public class SpringBootPropertySource implements PropertySource {
+
+	private static final String PREFIX = "log4j.";
+
+	private final Map<String, String> properties = Collections
+			.singletonMap(ShutdownCallbackRegistry.SHUTDOWN_HOOK_ENABLED, "false");
+
+	@Override
+	public void forEach(BiConsumer<String, String> action) {
+		this.properties.forEach((key, value) -> action.accept(key, value));
+	}
+
+	@Override
+	public CharSequence getNormalForm(Iterable<? extends CharSequence> tokens) {
+		return PREFIX + Util.joinAsCamelCase(tokens);
+	}
+
+	@Override
+	public int getPriority() {
+		return -200;
+	}
+
+}

spring-boot-project/spring-boot/src/main/resources/META-INF/services/org.apache.logging.log4j.util.PropertySource

@@ -0,0 +1 @@
+org.springframework.boot.logging.log4j2.SpringBootPropertySource

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

@@ -35,6 +35,8 @@ import org.apache.logging.log4j.core.LoggerContext;
 import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.logging.log4j.core.config.LoggerConfig;
 import org.apache.logging.log4j.core.config.Reconfigurable;
+import org.apache.logging.log4j.core.util.ShutdownCallbackRegistry;
+import org.apache.logging.log4j.util.PropertiesUtil;
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Disabled;
@@ -370,6 +372,13 @@ class Log4J2LoggingSystemTests extends AbstractLoggingSystemTests {
 				.isEqualTo(new LoggerConfiguration("com.example.test", LogLevel.WARN, LogLevel.WARN));
 	}
 
+	@Test
+	void shutdownHookIsDisabled() {
+		assertThat(
+				PropertiesUtil.getProperties().getBooleanProperty(ShutdownCallbackRegistry.SHUTDOWN_HOOK_ENABLED, true))
+						.isFalse();
+	}
+
 	private String getRelativeClasspathLocation(String fileName) {
 		String defaultPath = ClassUtils.getPackageName(getClass());
 		defaultPath = defaultPath.replace('.', '/');

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

@@ -1,42 +0,0 @@
-/*
- * Copyright 2012-2019 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.
- * You may obtain a copy of the License at
- *
- *      https://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.
- */
-
-package org.springframework.boot.logging.log4j2;
-
-import java.io.ByteArrayInputStream;
-import java.io.IOException;
-
-import org.apache.logging.log4j.core.LoggerContext;
-import org.apache.logging.log4j.core.config.ConfigurationSource;
-import org.junit.jupiter.api.Test;
-
-import static org.assertj.core.api.Assertions.assertThat;
-
-/**
- * Tests for {@link SpringBootConfigurationFactory}.
- *
- * @author Andy Wilkinson
- */
-class SpringBootConfigurationFactoryTests {
-
-	@Test
-	void producesConfigurationWithShutdownHookDisabled() throws IOException {
-		ConfigurationSource source = new ConfigurationSource(new ByteArrayInputStream(new byte[0]));
-		assertThat(new SpringBootConfigurationFactory().getConfiguration(new LoggerContext(""), source)
-				.isShutdownHookEnabled()).isFalse();
-	}
-
-}