Roll back to Log4j 2.24

This reverts:

 - 7a5e77fe67
 - 1590e4d2b3
 - 8cf0d17fbc

See gh-46334, gh-46372

config/checkstyle/checkstyle-suppressions.xml

@@ -75,7 +75,4 @@
 	<suppress files="ConditionMessage\.java" checks="NoWhitespaceBefore" message="'...' is preceded with whitespace"/>
 	<suppress files="EntityManagerFactoryBuilder\.java" checks="NoWhitespaceBefore" message="'...' is preceded with whitespace"/>
 	<suppress files="DockerApi\.java" checks="NoWhitespaceBefore" message="'...' is preceded with whitespace"/>
-	<!-- https://github.com/apache/logging-log4j2/issues/2769#issuecomment-3049020222 -->
-	<suppress files="SpringProfileArbiter\.java" checks="SpringMethodVisibility"/>
-	<suppress files="StructuredLogLayout\.java" checks="SpringMethodVisibility"/>
 </suppressions>

core/spring-boot/build.gradle

@@ -87,12 +87,6 @@ tasks.named("checkFormatMain") {
 	source(fileTree("src/main/javaTemplates"))
 }
 
-tasks.named("compileJava") {
-	// Provide the project coordinates to the `GraalVmProcessor`:
-	options.compilerArgs << '-Alog4j.graalvm.groupId=org.springframework.boot'
-	options.compilerArgs << '-Alog4j.graalvm.artifactId=spring-boot-log4j'
-}
-
 plugins.withType(EclipsePlugin) {
 	eclipse {
 		synchronizationTasks syncJavaTemplates

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/ElasticCommonSchemaStructuredLogFormatter.java

@@ -19,11 +19,11 @@ package org.springframework.boot.logging.log4j2;
 import java.util.Objects;
 import java.util.Set;
 import java.util.TreeSet;
-import java.util.function.Function;
 
 import org.apache.logging.log4j.Level;
 import org.apache.logging.log4j.Marker;
 import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.impl.ThrowableProxy;
 import org.apache.logging.log4j.core.time.Instant;
 import org.apache.logging.log4j.util.ReadOnlyStringMap;
 import org.jspecify.annotations.Nullable;
@@ -71,10 +71,10 @@ class ElasticCommonSchemaStructuredLogFormatter extends JsonWriterStructuredLogF
 		members.add("message", LogEvent::getMessage).as(StructuredMessage::get);
 		members.from(LogEvent::getContextData)
 			.usingPairs(contextPairs.nested(ElasticCommonSchemaStructuredLogFormatter::addContextDataPairs));
-		members.from(LogEvent::getThrown).whenNotNull().usingMembers((thrownProxyMembers) -> {
+		members.from(LogEvent::getThrownProxy).whenNotNull().usingMembers((thrownProxyMembers) -> {
 			thrownProxyMembers.add("error").usingMembers((error) -> {
-				error.add("type", Function.identity()).whenNotNull().as(ObjectUtils::nullSafeClassName);
-				error.add("message", Throwable::getMessage);
+				error.add("type", ThrowableProxy::getThrowable).whenNotNull().as(ObjectUtils::nullSafeClassName);
+				error.add("message", ThrowableProxy::getMessage);
 				error.add("stack_trace", extractor::stackTrace);
 			});
 		});

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/ExtendedWhitespaceThrowablePatternConverter.java

@@ -21,7 +21,6 @@ import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.logging.log4j.core.config.plugins.Plugin;
 import org.apache.logging.log4j.core.pattern.ConverterKeys;
 import org.apache.logging.log4j.core.pattern.ExtendedThrowablePatternConverter;
-import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
 import org.apache.logging.log4j.core.pattern.PatternConverter;
 import org.apache.logging.log4j.core.pattern.ThrowablePatternConverter;
 import org.jspecify.annotations.Nullable;
@@ -36,33 +35,24 @@ import org.jspecify.annotations.Nullable;
  */
 @Plugin(name = "ExtendedWhitespaceThrowablePatternConverter", category = PatternConverter.CATEGORY)
 @ConverterKeys({ "xwEx", "xwThrowable", "xwException" })
-public final class ExtendedWhitespaceThrowablePatternConverter extends LogEventPatternConverter {
+public final class ExtendedWhitespaceThrowablePatternConverter extends ThrowablePatternConverter {
 
 	private final ExtendedThrowablePatternConverter delegate;
 
-	private final String separator;
-
-	@SuppressWarnings("deprecation") // https://github.com/apache/logging-log4j2/issues/3809
-	private ExtendedWhitespaceThrowablePatternConverter(Configuration configuration, @Nullable String[] options) {
-		super("WhitespaceExtendedThrowable", "throwable");
+	private ExtendedWhitespaceThrowablePatternConverter(Configuration configuration, String @Nullable [] options) {
+		super("WhitespaceExtendedThrowable", "throwable", options, configuration);
 		this.delegate = ExtendedThrowablePatternConverter.newInstance(configuration, options);
-		this.separator = this.delegate.getOptions().getSeparator();
 	}
 
 	@Override
 	public void format(LogEvent event, StringBuilder buffer) {
 		if (event.getThrown() != null) {
-			buffer.append(this.separator);
+			buffer.append(this.options.getSeparator());
 			this.delegate.format(event, buffer);
-			buffer.append(this.separator);
+			buffer.append(this.options.getSeparator());
 		}
 	}
 
-	@Override
-	public boolean handlesThrowable() {
-		return true;
-	}
-
 	/**
 	 * Creates a new instance of the class. Required by Log4J2.
 	 * @param configuration current configuration
@@ -71,7 +61,7 @@ public final class ExtendedWhitespaceThrowablePatternConverter extends LogEventP
 	 * @return a new {@code WhitespaceThrowablePatternConverter}
 	 */
 	public static ExtendedWhitespaceThrowablePatternConverter newInstance(Configuration configuration,
-			@Nullable String[] options) {
+			String @Nullable [] options) {
 		return new ExtendedWhitespaceThrowablePatternConverter(configuration, options);
 	}
 

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/Extractor.java

@@ -16,14 +16,13 @@
 
 package org.springframework.boot.logging.log4j2;
 
-import java.io.PrintWriter;
-import java.io.StringWriter;
-
 import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.impl.ThrowableProxy;
 import org.jspecify.annotations.Nullable;
 import org.slf4j.event.LoggingEvent;
 
 import org.springframework.boot.logging.StackTracePrinter;
+import org.springframework.util.Assert;
 
 /**
  * Functions to extract items from {@link LoggingEvent}.
@@ -43,23 +42,19 @@ class Extractor {
 	}
 
 	@Nullable String stackTrace(LogEvent event) {
-		return stackTrace(event.getThrown());
+		return stackTrace(event.getThrownProxy());
 	}
 
-	@Nullable String stackTrace(@Nullable Throwable throwable) {
-		if (throwable == null) {
+	@Nullable String stackTrace(@Nullable ThrowableProxy throwableProxy) {
+		if (throwableProxy == null) {
 			return null;
 		}
 		if (this.stackTracePrinter != null) {
+			Throwable throwable = throwableProxy.getThrowable();
+			Assert.state(throwable != null, "Proxy must return Throwable in order to print exception");
 			return this.stackTracePrinter.printStackTraceToString(throwable);
 		}
-		return printStackTrace(throwable);
-	}
-
-	private static String printStackTrace(Throwable throwable) {
-		StringWriter stringWriter = new StringWriter();
-		throwable.printStackTrace(new PrintWriter(stringWriter));
-		return stringWriter.toString();
+		return throwableProxy.getExtendedStackTraceAsString();
 	}
 
 }

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/GraylogExtendedLogFormatStructuredLogFormatter.java

@@ -98,8 +98,8 @@ class GraylogExtendedLogFormatStructuredLogFormatter extends JsonWriterStructure
 			.usingPairs(contextPairs.flat(additionalFieldJoiner(),
 					GraylogExtendedLogFormatStructuredLogFormatter::addContextDataPairs));
 		members.add()
-			.whenNotNull(LogEvent::getThrown)
-			.usingMembers((thrownMembers) -> throwableMembers(thrownMembers, extractor));
+			.whenNotNull(LogEvent::getThrownProxy)
+			.usingMembers((thrownProxyMembers) -> throwableMembers(thrownProxyMembers, extractor));
 	}
 
 	private static String getMessageText(Message message) {
@@ -131,9 +131,11 @@ class GraylogExtendedLogFormatStructuredLogFormatter extends JsonWriterStructure
 
 	private static void throwableMembers(Members<LogEvent> members, Extractor extractor) {
 		members.add("full_message", extractor::messageAndStackTrace);
-		members.add("_error_type", LogEvent::getThrown).whenNotNull().as(ObjectUtils::nullSafeClassName);
+		members.add("_error_type", (event) -> event.getThrownProxy().getThrowable())
+			.whenNotNull()
+			.as(ObjectUtils::nullSafeClassName);
 		members.add("_error_stack_trace", extractor::stackTrace);
-		members.add("_error_message", (event) -> event.getThrown().getMessage());
+		members.add("_error_message", (event) -> event.getThrownProxy().getMessage());
 	}
 
 	private static void addContextDataPairs(ContextPairs.Pairs<ReadOnlyStringMap> contextPairs) {

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/LogstashStructuredLogFormatter.java

@@ -68,7 +68,7 @@ class LogstashStructuredLogFormatter extends JsonWriterStructuredLogFormatter<Lo
 			.whenNotNull()
 			.as(LogstashStructuredLogFormatter::getMarkers)
 			.whenNot(CollectionUtils::isEmpty);
-		members.add("stack_trace", LogEvent::getThrown).whenNotNull().as(extractor::stackTrace);
+		members.add("stack_trace", LogEvent::getThrownProxy).whenNotNull().as(extractor::stackTrace);
 	}
 
 	private static String asTimestamp(Instant instant) {

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/SpringProfileArbiter.java

@@ -90,7 +90,7 @@ final class SpringProfileArbiter implements Arbiter {
 		 * @return this
 		 * @see Profiles#of(String...)
 		 */
-		public Builder setName(String name) {
+		Builder setName(String name) {
 			this.name = name;
 			return this;
 		}

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/StructuredLogLayout.java

@@ -87,12 +87,12 @@ final class StructuredLogLayout extends AbstractStringLayout {
 		@SuppressWarnings("NullAway.Init")
 		private String charset = StandardCharsets.UTF_8.name();
 
-		public Builder setFormat(String format) {
+		Builder setFormat(String format) {
 			this.format = format;
 			return this;
 		}
 
-		public Builder setCharset(String charset) {
+		Builder setCharset(String charset) {
 			this.charset = charset;
 			return this;
 		}

core/spring-boot/src/main/java/org/springframework/boot/logging/log4j2/WhitespaceThrowablePatternConverter.java

@@ -20,8 +20,6 @@ import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.config.Configuration;
 import org.apache.logging.log4j.core.config.plugins.Plugin;
 import org.apache.logging.log4j.core.pattern.ConverterKeys;
-import org.apache.logging.log4j.core.pattern.ExtendedThrowablePatternConverter;
-import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
 import org.apache.logging.log4j.core.pattern.PatternConverter;
 import org.apache.logging.log4j.core.pattern.ThrowablePatternConverter;
 import org.jspecify.annotations.Nullable;
@@ -35,33 +33,21 @@ import org.jspecify.annotations.Nullable;
  */
 @Plugin(name = "WhitespaceThrowablePatternConverter", category = PatternConverter.CATEGORY)
 @ConverterKeys({ "wEx", "wThrowable", "wException" })
-public final class WhitespaceThrowablePatternConverter extends LogEventPatternConverter {
+public final class WhitespaceThrowablePatternConverter extends ThrowablePatternConverter {
 
-	private final ExtendedThrowablePatternConverter delegate;
-
-	private final String separator;
-
-	@SuppressWarnings("deprecation") // https://github.com/apache/logging-log4j2/issues/3809
-	private WhitespaceThrowablePatternConverter(Configuration configuration, @Nullable String[] options) {
-		super("WhitespaceThrowable", "throwable");
-		this.delegate = ExtendedThrowablePatternConverter.newInstance(configuration, options);
-		this.separator = this.delegate.getOptions().getSeparator();
+	private WhitespaceThrowablePatternConverter(Configuration configuration, String @Nullable [] options) {
+		super("WhitespaceThrowable", "throwable", options, configuration);
 	}
 
 	@Override
 	public void format(LogEvent event, StringBuilder buffer) {
 		if (event.getThrown() != null) {
-			buffer.append(this.separator);
-			this.delegate.format(event, buffer);
-			buffer.append(this.separator);
+			buffer.append(this.options.getSeparator());
+			super.format(event, buffer);
+			buffer.append(this.options.getSeparator());
 		}
 	}
 
-	@Override
-	public boolean handlesThrowable() {
-		return true;
-	}
-
 	/**
 	 * Creates a new instance of the class. Required by Log4J2.
 	 * @param configuration current configuration
@@ -70,7 +56,7 @@ public final class WhitespaceThrowablePatternConverter extends LogEventPatternCo
 	 * @return a new {@code WhitespaceThrowablePatternConverter}
 	 */
 	public static WhitespaceThrowablePatternConverter newInstance(Configuration configuration,
-			@Nullable String[] options) {
+			String @Nullable [] options) {
 		return new WhitespaceThrowablePatternConverter(configuration, options);
 	}
 

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/ElasticCommonSchemaStructuredLogFormatterTests.java

@@ -101,14 +101,13 @@ class ElasticCommonSchemaStructuredLogFormatterTests extends AbstractStructuredL
 		expectedError.put("message", "Boom");
 		assertThat(error).containsAllEntriesOf(expectedError);
 		String stackTrace = (String) error.get("stack_trace");
-		assertThat(stackTrace)
-			.startsWith(String.format("java.lang.RuntimeException: Boom%n\tat org.springframework.boot.logging.log4j2."
-					+ "ElasticCommonSchemaStructuredLogFormatterTests.shouldFormatException"));
-		assertThat(json).contains(String
-			.format("java.lang.RuntimeException: Boom%n\\tat org.springframework.boot.logging.log4j2."
-					+ "ElasticCommonSchemaStructuredLogFormatterTests.shouldFormatException")
-			.replace("\n", "\\n")
-			.replace("\r", "\\r"));
+		assertThat(stackTrace).startsWith(
+				"""
+						java.lang.RuntimeException: Boom
+						\tat org.springframework.boot.logging.log4j2.ElasticCommonSchemaStructuredLogFormatterTests.shouldFormatException""");
+		assertThat(json).contains(
+				"""
+						java.lang.RuntimeException: Boom\\n\\tat org.springframework.boot.logging.log4j2.ElasticCommonSchemaStructuredLogFormatterTests.shouldFormatException""");
 	}
 
 	@Test

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/ExtendedWhitespaceThrowablePatternConverterTests.java

@@ -19,7 +19,7 @@ package org.springframework.boot.logging.log4j2;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.config.DefaultConfiguration;
 import org.apache.logging.log4j.core.impl.Log4jLogEvent;
-import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
+import org.apache.logging.log4j.core.pattern.ThrowablePatternConverter;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -32,7 +32,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 class ExtendedWhitespaceThrowablePatternConverterTests {
 
-	private final LogEventPatternConverter converter = ExtendedWhitespaceThrowablePatternConverter
+	private final ThrowablePatternConverter converter = ExtendedWhitespaceThrowablePatternConverter
 		.newInstance(new DefaultConfiguration(), new String[] {});
 
 	@Test

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/GraylogExtendedLogFormatStructuredLogFormatterTests.java

@@ -136,18 +136,21 @@ class GraylogExtendedLogFormatStructuredLogFormatterTests extends AbstractStruct
 		String fullMessage = (String) deserialized.get("full_message");
 		String stackTrace = (String) deserialized.get("_error_stack_trace");
 		assertThat(fullMessage).startsWith(
-				"message\n\njava.lang.RuntimeException: Boom%n\tat org.springframework.boot.logging.log4j2.GraylogExtendedLogFormatStructuredLogFormatterTests.shouldFormatException"
-					.formatted());
+				"""
+						message
+
+						java.lang.RuntimeException: Boom
+						\tat org.springframework.boot.logging.log4j2.GraylogExtendedLogFormatStructuredLogFormatterTests.shouldFormatException""");
+		assertThat(stackTrace).startsWith(
+				"""
+						java.lang.RuntimeException: Boom
+						\tat org.springframework.boot.logging.log4j2.GraylogExtendedLogFormatStructuredLogFormatterTests.shouldFormatException""");
+
 		assertThat(deserialized)
 			.containsAllEntriesOf(map("_error_type", "java.lang.RuntimeException", "_error_message", "Boom"));
-		assertThat(stackTrace).startsWith(
-				"java.lang.RuntimeException: Boom%n\tat org.springframework.boot.logging.log4j2.GraylogExtendedLogFormatStructuredLogFormatterTests.shouldFormatException"
-					.formatted());
 		assertThat(json).contains(
-				"java.lang.RuntimeException: Boom%n\\tat org.springframework.boot.logging.log4j2.GraylogExtendedLogFormatStructuredLogFormatterTests.shouldFormatException"
-					.formatted()
-					.replace("\n", "\\n")
-					.replace("\r", "\\r"));
+				"""
+						message\\n\\njava.lang.RuntimeException: Boom\\n\\tat org.springframework.boot.logging.log4j2.GraylogExtendedLogFormatStructuredLogFormatterTests.shouldFormatException""");
 	}
 
 	@Test

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/LogstashStructuredLogFormatterTests.java

@@ -80,13 +80,12 @@ class LogstashStructuredLogFormatterTests extends AbstractStructuredLoggingTests
 		Map<String, Object> deserialized = deserialize(json);
 		String stackTrace = (String) deserialized.get("stack_trace");
 		assertThat(stackTrace).startsWith(
-				"java.lang.RuntimeException: Boom%n\tat org.springframework.boot.logging.log4j2.LogstashStructuredLogFormatterTests.shouldFormatException"
-					.formatted());
+				"""
+						java.lang.RuntimeException: Boom
+						\tat org.springframework.boot.logging.log4j2.LogstashStructuredLogFormatterTests.shouldFormatException""");
 		assertThat(json).contains(
-				"java.lang.RuntimeException: Boom%n\\tat org.springframework.boot.logging.log4j2.LogstashStructuredLogFormatterTests.shouldFormatException"
-					.formatted()
-					.replace("\n", "\\n")
-					.replace("\r", "\\r"));
+				"""
+						java.lang.RuntimeException: Boom\\n\\tat org.springframework.boot.logging.log4j2.LogstashStructuredLogFormatterTests.shouldFormatException""");
 	}
 
 	@Test

core/spring-boot/src/test/java/org/springframework/boot/logging/log4j2/WhitespaceThrowablePatternConverterTests.java

@@ -19,7 +19,7 @@ package org.springframework.boot.logging.log4j2;
 import org.apache.logging.log4j.core.LogEvent;
 import org.apache.logging.log4j.core.config.DefaultConfiguration;
 import org.apache.logging.log4j.core.impl.Log4jLogEvent;
-import org.apache.logging.log4j.core.pattern.LogEventPatternConverter;
+import org.apache.logging.log4j.core.pattern.ThrowablePatternConverter;
 import org.junit.jupiter.api.Test;
 
 import static org.assertj.core.api.Assertions.assertThat;
@@ -31,7 +31,7 @@ import static org.assertj.core.api.Assertions.assertThat;
  */
 class WhitespaceThrowablePatternConverterTests {
 
-	private final LogEventPatternConverter converter = WhitespaceThrowablePatternConverter
+	private final ThrowablePatternConverter converter = WhitespaceThrowablePatternConverter
 		.newInstance(new DefaultConfiguration(), new String[] {});
 
 	@Test

core/spring-boot/src/test/java/org/springframework/boot/logging/logback/ExtractorTests.java

@@ -46,7 +46,7 @@ class ExtractorTests {
 	}
 
 	@Test
-	void stackTraceWhenNoPrinterPrintsUsingFallback() {
+	void stackTraceWhenNoPrinterPrintsUsingLoggingSystem() {
 		Extractor extractor = new Extractor(null, createConverter());
 		assertThat(extractor.stackTrace(createEvent())).contains("java.lang.RuntimeException: Boom!");
 	}

platform/spring-boot-dependencies/build.gradle

@@ -1252,14 +1252,23 @@ bom {
 			releaseNotes("https://github.com/liquibase/liquibase/releases/tag/v{version}")
 		}
 	}
-	library("Log4j2", "2.25.1") {
+	library("Log4j2", "2.24.3") {
 		prohibit {
 			contains "-alpha"
 			contains "-beta"
 			because "we don't want alphas or betas"
 		}
 		group("org.apache.logging.log4j") {
-			bom("log4j-bom")
+			bom("log4j-bom") {
+				permit("biz.aQute.bnd:biz.aQute.bnd.annotation")
+				permit("com.github.spotbugs:spotbugs-annotations")
+				permit("org.apache.logging:logging-parent")
+				permit("org.apache.maven.plugin-tools:maven-plugin-annotations")
+				permit("org.jspecify:jspecify")
+				permit("org.osgi:org.osgi.annotation.bundle")
+				permit("org.osgi:org.osgi.annotation.versioning")
+				permit("org.osgi:osgi.annotation")
+			}
 		}
 		links {
 			site("https://logging.apache.org/log4j")

smoke-test/spring-boot-smoke-test-structured-logging-log4j2/src/main/java/smoketest/structuredlogging/log4j2/CustomStructuredLogFormatter.java

@@ -16,10 +16,8 @@
 
 package smoketest.structuredlogging.log4j2;
 
-import java.io.PrintWriter;
-import java.io.StringWriter;
-
 import org.apache.logging.log4j.core.LogEvent;
+import org.apache.logging.log4j.core.impl.ThrowableProxy;
 import org.jspecify.annotations.Nullable;
 
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
@@ -41,11 +39,9 @@ public class CustomStructuredLogFormatter implements StructuredLogFormatter<LogE
 			result.append(" pid=").append(this.pid);
 		}
 		result.append(" msg=\"").append(event.getMessage().getFormattedMessage()).append('"');
-		Throwable throwable = event.getThrown();
+		ThrowableProxy throwable = event.getThrownProxy();
 		if (throwable != null) {
-			StringWriter stackTrace = new StringWriter();
-			throwable.printStackTrace(new PrintWriter(stackTrace));
-			result.append(" error=\"").append(stackTrace).append('"');
+			result.append(" error=\"").append(throwable.getExtendedStackTraceAsString()).append('"');
 		}
 		result.append('\n');
 		return result.toString();