Add structured logging stacktrace hash field

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

@@ -278,6 +278,35 @@ public StandardStackTracePrinter withHashes(@Nullable ToIntFunction<StackTraceEl
 				this.frameFilter, this.formatter, this.frameFormatter, frameHasher);
 	}
 
+	/**
+	 * Compute a hash for the given throwable using the default frame hasher and return it
+	 * as a zero-padded 8-character hex string.
+	 * @param throwable the throwable to hash
+	 * @return the hash as a hex string, or {@code null} if the throwable is {@code null}
+	 * @since 4.0.0
+	 */
+	public static @Nullable String hashAsHexString(@Nullable Throwable throwable) {
+		return hashAsHexString(throwable, DEFAULT_FRAME_HASHER);
+	}
+
+	/**
+	 * Compute a hash for the given throwable using the specified frame hasher and return
+	 * it as a zero-padded 8-character hex string.
+	 * @param throwable the throwable to hash
+	 * @param frameHasher the function used to hash individual stack trace elements
+	 * @return the hash as a hex string, or {@code null} if the throwable is {@code null}
+	 * @since 4.0.0
+	 */
+	public static @Nullable String hashAsHexString(@Nullable Throwable throwable,
+			ToIntFunction<StackTraceElement> frameHasher) {
+		if (throwable == null) {
+			return null;
+		}
+		StackTrace stackTrace = new StackTrace(throwable);
+		int hash = stackTrace.hash(new HashSet<>(), frameHasher);
+		return String.format("%08x", hash);
+	}
+
 	private StandardStackTracePrinter withOption(Option option) {
 		EnumSet<Option> options = EnumSet.copyOf(this.options);
 		options.add(option);

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

@@ -33,6 +33,7 @@
 import org.springframework.boot.logging.structured.ContextPairs.Pairs;
 import org.springframework.boot.logging.structured.ElasticCommonSchemaProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
+import org.springframework.boot.logging.structured.StackTraceHashFieldConfiguration;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLoggingJsonMembersCustomizer;
 import org.springframework.core.env.Environment;
@@ -48,13 +49,15 @@
 class ElasticCommonSchemaStructuredLogFormatter extends JsonWriterStructuredLogFormatter<LogEvent> {
 
 	ElasticCommonSchemaStructuredLogFormatter(Environment environment, @Nullable StackTracePrinter stackTracePrinter,
-			ContextPairs contextPairs, StructuredLoggingJsonMembersCustomizer.Builder<?> customizerBuilder) {
-		super((members) -> jsonMembers(environment, stackTracePrinter, contextPairs, members),
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
+			StructuredLoggingJsonMembersCustomizer.Builder<?> customizerBuilder) {
+		super((members) -> jsonMembers(environment, stackTracePrinter, hashFieldConfiguration, contextPairs, members),
 				customizerBuilder.nested().build());
 	}
 
 	private static void jsonMembers(Environment environment, @Nullable StackTracePrinter stackTracePrinter,
-			ContextPairs contextPairs, JsonWriter.Members<LogEvent> members) {
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
+			JsonWriter.Members<LogEvent> members) {
 		Extractor extractor = new Extractor(stackTracePrinter);
 		members.add("@timestamp", LogEvent::getInstant).as(ElasticCommonSchemaStructuredLogFormatter::asTimestamp);
 		members.add("log").usingMembers((log) -> {
@@ -76,6 +79,11 @@ private static void jsonMembers(Environment environment, @Nullable StackTracePri
 				error.add("message", Throwable::getMessage);
 				error.add("stack_trace", extractor::stackTrace);
 			}));
+		if (hashFieldConfiguration != null) {
+			members.add(hashFieldConfiguration.getFieldName(), LogEvent::getThrown)
+				.whenNotNull()
+				.as(hashFieldConfiguration::computeHash);
+		}
 		members.add("tags", LogEvent::getMarker)
 			.whenNotNull()
 			.as(ElasticCommonSchemaStructuredLogFormatter::getMarkers)

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

@@ -41,6 +41,7 @@
 import org.springframework.boot.logging.structured.ContextPairs.Joiner;
 import org.springframework.boot.logging.structured.GraylogExtendedLogFormatProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
+import org.springframework.boot.logging.structured.StackTraceHashFieldConfiguration;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLoggingJsonMembersCustomizer;
 import org.springframework.core.env.Environment;
@@ -74,13 +75,16 @@ class GraylogExtendedLogFormatStructuredLogFormatter extends JsonWriterStructure
 	private static final Set<String> ADDITIONAL_FIELD_ILLEGAL_KEYS = Set.of("id", "_id");
 
 	GraylogExtendedLogFormatStructuredLogFormatter(Environment environment,
-			@Nullable StackTracePrinter stackTracePrinter, ContextPairs contextPairs,
+			@Nullable StackTracePrinter stackTracePrinter,
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
 			@Nullable StructuredLoggingJsonMembersCustomizer<?> customizer) {
-		super((members) -> jsonMembers(environment, stackTracePrinter, contextPairs, members), customizer);
+		super((members) -> jsonMembers(environment, stackTracePrinter, hashFieldConfiguration, contextPairs, members),
+				customizer);
 	}
 
 	private static void jsonMembers(Environment environment, @Nullable StackTracePrinter stackTracePrinter,
-			ContextPairs contextPairs, JsonWriter.Members<LogEvent> members) {
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
+			JsonWriter.Members<LogEvent> members) {
 		Extractor extractor = new Extractor(stackTracePrinter);
 		members.add("version", "1.1");
 		members.add("short_message", LogEvent::getMessage)
@@ -103,6 +107,11 @@ private static void jsonMembers(Environment environment, @Nullable StackTracePri
 		members.add()
 			.whenNotNull(getThrown)
 			.usingMembers((thrownMembers) -> throwableMembers(thrownMembers, extractor));
+		if (hashFieldConfiguration != null) {
+			members.add(hashFieldConfiguration.getFieldName(), LogEvent::getThrown)
+				.whenNotNull()
+				.as(hashFieldConfiguration::computeHash);
+		}
 	}
 
 	private static String getMessageText(Message message) {

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

@@ -35,6 +35,7 @@
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
 import org.springframework.boot.logging.structured.ContextPairs;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
+import org.springframework.boot.logging.structured.StackTraceHashFieldConfiguration;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLoggingJsonMembersCustomizer;
 import org.springframework.util.CollectionUtils;
@@ -47,12 +48,14 @@
  */
 class LogstashStructuredLogFormatter extends JsonWriterStructuredLogFormatter<LogEvent> {
 
-	LogstashStructuredLogFormatter(@Nullable StackTracePrinter stackTracePrinter, ContextPairs contextPairs,
+	LogstashStructuredLogFormatter(@Nullable StackTracePrinter stackTracePrinter,
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
 			@Nullable StructuredLoggingJsonMembersCustomizer<?> customizer) {
-		super((members) -> jsonMembers(stackTracePrinter, contextPairs, members), customizer);
+		super((members) -> jsonMembers(stackTracePrinter, hashFieldConfiguration, contextPairs, members), customizer);
 	}
 
-	private static void jsonMembers(@Nullable StackTracePrinter stackTracePrinter, ContextPairs contextPairs,
+	private static void jsonMembers(@Nullable StackTracePrinter stackTracePrinter,
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
 			JsonWriter.Members<LogEvent> members) {
 		Extractor extractor = new Extractor(stackTracePrinter);
 		members.add("@timestamp", LogEvent::getInstant).as(LogstashStructuredLogFormatter::asTimestamp);
@@ -72,6 +75,11 @@ private static void jsonMembers(@Nullable StackTracePrinter stackTracePrinter, C
 			.as(LogstashStructuredLogFormatter::getMarkers)
 			.whenNot(collectionIsEmpty);
 		members.add("stack_trace", LogEvent::getThrown).whenNotNull().as(extractor::stackTrace);
+		if (hashFieldConfiguration != null) {
+			members.add(hashFieldConfiguration.getFieldName(), LogEvent::getThrown)
+				.whenNotNull()
+				.as(hashFieldConfiguration::computeHash);
+		}
 	}
 
 	private static String asTimestamp(Instant instant) {

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

@@ -32,6 +32,7 @@
 import org.springframework.boot.logging.StackTracePrinter;
 import org.springframework.boot.logging.structured.CommonStructuredLogFormat;
 import org.springframework.boot.logging.structured.ContextPairs;
+import org.springframework.boot.logging.structured.StackTraceHashFieldConfiguration;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLogFormatterFactory;
 import org.springframework.boot.logging.structured.StructuredLogFormatterFactory.CommonFormatters;
@@ -117,35 +118,42 @@ private void addCommonFormatters(CommonFormatters<LogEvent> commonFormatters) {
 		private ElasticCommonSchemaStructuredLogFormatter createEcsFormatter(Instantiator<?> instantiator) {
 			Environment environment = instantiator.getArg(Environment.class);
 			StackTracePrinter stackTracePrinter = instantiator.getArg(StackTracePrinter.class);
+			StackTraceHashFieldConfiguration hashFieldConfiguration = instantiator
+				.getArg(StackTraceHashFieldConfiguration.class);
 			ContextPairs contextPairs = instantiator.getArg(ContextPairs.class);
 			StructuredLoggingJsonMembersCustomizer.Builder<?> jsonMembersCustomizerBuilder = instantiator
 				.getArg(StructuredLoggingJsonMembersCustomizer.Builder.class);
 			Assert.state(environment != null, "'environment' must not be null");
 			Assert.state(contextPairs != null, "'contextPairs' must not be null");
 			Assert.state(jsonMembersCustomizerBuilder != null, "'jsonMembersCustomizerBuilder' must not be null");
-			return new ElasticCommonSchemaStructuredLogFormatter(environment, stackTracePrinter, contextPairs,
-					jsonMembersCustomizerBuilder);
+			return new ElasticCommonSchemaStructuredLogFormatter(environment, stackTracePrinter, hashFieldConfiguration,
+					contextPairs, jsonMembersCustomizerBuilder);
 		}
 
 		private GraylogExtendedLogFormatStructuredLogFormatter createGraylogFormatter(Instantiator<?> instantiator) {
 			Environment environment = instantiator.getArg(Environment.class);
 			StackTracePrinter stackTracePrinter = instantiator.getArg(StackTracePrinter.class);
+			StackTraceHashFieldConfiguration hashFieldConfiguration = instantiator
+				.getArg(StackTraceHashFieldConfiguration.class);
 			ContextPairs contextPairs = instantiator.getArg(ContextPairs.class);
 			StructuredLoggingJsonMembersCustomizer<?> jsonMembersCustomizer = instantiator
 				.getArg(StructuredLoggingJsonMembersCustomizer.class);
 			Assert.state(environment != null, "'environment' must not be null");
 			Assert.state(contextPairs != null, "'contextPairs' must not be null");
-			return new GraylogExtendedLogFormatStructuredLogFormatter(environment, stackTracePrinter, contextPairs,
-					jsonMembersCustomizer);
+			return new GraylogExtendedLogFormatStructuredLogFormatter(environment, stackTracePrinter,
+					hashFieldConfiguration, contextPairs, jsonMembersCustomizer);
 		}
 
 		private LogstashStructuredLogFormatter createLogstashFormatter(Instantiator<?> instantiator) {
 			StackTracePrinter stackTracePrinter = instantiator.getArg(StackTracePrinter.class);
+			StackTraceHashFieldConfiguration hashFieldConfiguration = instantiator
+				.getArg(StackTraceHashFieldConfiguration.class);
 			ContextPairs contextPairs = instantiator.getArg(ContextPairs.class);
 			StructuredLoggingJsonMembersCustomizer<?> jsonMembersCustomizer = instantiator
 				.getArg(StructuredLoggingJsonMembersCustomizer.class);
 			Assert.state(contextPairs != null, "'contextPairs' must not be null");
-			return new LogstashStructuredLogFormatter(stackTracePrinter, contextPairs, jsonMembersCustomizer);
+			return new LogstashStructuredLogFormatter(stackTracePrinter, hashFieldConfiguration, contextPairs,
+					jsonMembersCustomizer);
 		}
 
 	}

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

@@ -36,6 +36,7 @@
 import org.springframework.boot.logging.structured.ContextPairs;
 import org.springframework.boot.logging.structured.ElasticCommonSchemaProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
+import org.springframework.boot.logging.structured.StackTraceHashFieldConfiguration;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLoggingJsonMembersCustomizer;
 import org.springframework.core.env.Environment;
@@ -53,15 +54,16 @@ class ElasticCommonSchemaStructuredLogFormatter extends JsonWriterStructuredLogF
 			(pair) -> pair.value);
 
 	ElasticCommonSchemaStructuredLogFormatter(Environment environment, @Nullable StackTracePrinter stackTracePrinter,
-			ContextPairs contextPairs, ThrowableProxyConverter throwableProxyConverter,
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
+			ThrowableProxyConverter throwableProxyConverter,
 			StructuredLoggingJsonMembersCustomizer.Builder<?> customizerBuilder) {
-		super((members) -> jsonMembers(environment, stackTracePrinter, contextPairs, throwableProxyConverter, members),
-				customizerBuilder.nested().build());
+		super((members) -> jsonMembers(environment, stackTracePrinter, hashFieldConfiguration, contextPairs,
+				throwableProxyConverter, members), customizerBuilder.nested().build());
 	}
 
 	private static void jsonMembers(Environment environment, @Nullable StackTracePrinter stackTracePrinter,
-			ContextPairs contextPairs, ThrowableProxyConverter throwableProxyConverter,
-			JsonWriter.Members<ILoggingEvent> members) {
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
+			ThrowableProxyConverter throwableProxyConverter, JsonWriter.Members<ILoggingEvent> members) {
 		Extractor extractor = new Extractor(stackTracePrinter, throwableProxyConverter);
 		members.add("@timestamp", ILoggingEvent::getInstant);
 		members.add("log").usingMembers((log) -> {
@@ -87,13 +89,25 @@ private static void jsonMembers(Environment environment, @Nullable StackTracePri
 				error.add("stack_trace", extractor::stackTrace);
 			});
 		});
+		if (hashFieldConfiguration != null) {
+			members.add(hashFieldConfiguration.getFieldName(), (event) -> event)
+				.whenNotNull(getThrowableProxy)
+				.as((event) -> hashFieldConfiguration.computeHash(extractThrowable(event)));
+		}
 		members.add("tags", ILoggingEvent::getMarkerList)
 			.whenNotNull()
 			.as(ElasticCommonSchemaStructuredLogFormatter::getMarkers)
 			.whenNotEmpty();
 		members.add("ecs").usingMembers((ecs) -> ecs.add("version", "8.11"));
 	}
 
+	private static @Nullable Throwable extractThrowable(ILoggingEvent event) {
+		if (event.getThrowableProxy() instanceof ch.qos.logback.classic.spi.ThrowableProxy throwableProxy) {
+			return throwableProxy.getThrowable();
+		}
+		return null;
+	}
+
 	private static Set<String> getMarkers(List<Marker> markers) {
 		Set<String> result = new TreeSet<>();
 		addMarkers(result, markers.iterator());

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

@@ -40,6 +40,7 @@
 import org.springframework.boot.logging.structured.ContextPairs.Joiner;
 import org.springframework.boot.logging.structured.GraylogExtendedLogFormatProperties;
 import org.springframework.boot.logging.structured.JsonWriterStructuredLogFormatter;
+import org.springframework.boot.logging.structured.StackTraceHashFieldConfiguration;
 import org.springframework.boot.logging.structured.StructuredLogFormatter;
 import org.springframework.boot.logging.structured.StructuredLoggingJsonMembersCustomizer;
 import org.springframework.core.env.Environment;
@@ -75,16 +76,17 @@ class GraylogExtendedLogFormatStructuredLogFormatter extends JsonWriterStructure
 	private static final Set<String> ADDITIONAL_FIELD_ILLEGAL_KEYS = Set.of("id", "_id");
 
 	GraylogExtendedLogFormatStructuredLogFormatter(Environment environment,
-			@Nullable StackTracePrinter stackTracePrinter, ContextPairs contextPairs,
+			@Nullable StackTracePrinter stackTracePrinter,
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
 			ThrowableProxyConverter throwableProxyConverter,
 			@Nullable StructuredLoggingJsonMembersCustomizer<?> customizer) {
-		super((members) -> jsonMembers(environment, stackTracePrinter, contextPairs, throwableProxyConverter, members),
-				customizer);
+		super((members) -> jsonMembers(environment, stackTracePrinter, hashFieldConfiguration, contextPairs,
+				throwableProxyConverter, members), customizer);
 	}
 
 	private static void jsonMembers(Environment environment, @Nullable StackTracePrinter stackTracePrinter,
-			ContextPairs contextPairs, ThrowableProxyConverter throwableProxyConverter,
-			JsonWriter.Members<ILoggingEvent> members) {
+			@Nullable StackTraceHashFieldConfiguration hashFieldConfiguration, ContextPairs contextPairs,
+			ThrowableProxyConverter throwableProxyConverter, JsonWriter.Members<ILoggingEvent> members) {
 		Extractor extractor = new Extractor(stackTracePrinter, throwableProxyConverter);
 		members.add("version", "1.1");
 		members.add("short_message", ILoggingEvent::getFormattedMessage)
@@ -106,6 +108,18 @@ private static void jsonMembers(Environment environment, @Nullable StackTracePri
 		members.add()
 			.whenNotNull(getThrowableProxy)
 			.usingMembers((throwableMembers) -> throwableMembers(throwableMembers, extractor));
+		if (hashFieldConfiguration != null) {
+			members.add(hashFieldConfiguration.getFieldName(), (event) -> event)
+				.whenNotNull(getThrowableProxy)
+				.as((event) -> hashFieldConfiguration.computeHash(extractThrowable(event)));
+		}
+	}
+
+	private static @Nullable Throwable extractThrowable(ILoggingEvent event) {
+		if (event.getThrowableProxy() instanceof ch.qos.logback.classic.spi.ThrowableProxy throwableProxy) {
+			return throwableProxy.getThrowable();
+		}
+		return null;
 	}
 
 	private static String getMessageText(String formattedMessage) {