spring-projectsGH-2800: wire configuration from annotation and traver…

…se causes

Closes spring-projects#2800

spring-kafka/src/main/java/org/springframework/kafka/annotation/RetryableTopic.java

@@ -22,18 +22,13 @@
 import java.lang.annotation.RetentionPolicy;
 import java.lang.annotation.Target;
 
-import org.springframework.kafka.retrytopic.ExceptionBasedDltRouting;
 import org.springframework.kafka.retrytopic.DltStrategy;
+import org.springframework.kafka.retrytopic.ExceptionBasedDltRouting;
 import org.springframework.kafka.retrytopic.RetryTopicConstants;
 import org.springframework.kafka.retrytopic.SameIntervalTopicReuseStrategy;
 import org.springframework.kafka.retrytopic.TopicSuffixingStrategy;
 import org.springframework.retry.annotation.Backoff;
 
-
-// TODO
-// 2. inject exception detection when sending to DLT (consider traversing causes)
-// 3. route the message to the configured additional destination or to the default DLT
-
 /**
  *
  * Annotation to create the retry and dlt topics for a {@link KafkaListener} annotated
@@ -45,6 +40,7 @@
  * @author Gary Russell
  * @author Fabio da Silva Jr.
  * @author João Lima
+ * @author Adrian Chlebosz
  * @since 2.7
  *
  * @see org.springframework.kafka.retrytopic.RetryTopicConfigurer
@@ -177,7 +173,12 @@
 	 */
 	String dltTopicSuffix() default RetryTopicConstants.DEFAULT_DLT_SUFFIX;
 
-	ExceptionBasedDltRouting additionalExceptionBasedDltRouting() default @ExceptionBasedDltRouting;
+	/**
+	 * The DLT routing allowing to redirect the message to the custom DLT based on the
+	 * exception thrown during the processing.
+	 * @return the exception based DLT routing
+	 */
+	ExceptionBasedDltRouting exceptionBasedDltRouting() default @ExceptionBasedDltRouting;
 
 	/**
 	 * Whether the retry topics will be suffixed with the delay value for that topic or a

spring-kafka/src/main/java/org/springframework/kafka/annotation/RetryableTopicAnnotationProcessor.java

@@ -20,6 +20,9 @@
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.stream.Collectors;
 
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanInitializationException;
@@ -32,6 +35,8 @@
 import org.springframework.core.annotation.AnnotationUtils;
 import org.springframework.expression.spel.support.StandardEvaluationContext;
 import org.springframework.kafka.core.KafkaOperations;
+import org.springframework.kafka.retrytopic.ExceptionBasedDestinationDlt;
+import org.springframework.kafka.retrytopic.ExceptionBasedDltRouting;
 import org.springframework.kafka.retrytopic.RetryTopicBeanNames;
 import org.springframework.kafka.retrytopic.RetryTopicConfiguration;
 import org.springframework.kafka.retrytopic.RetryTopicConfigurationBuilder;
@@ -55,6 +60,7 @@
  *
  * @author Tomaz Fernandes
  * @author Gary Russell
+ * @author Adrian Chlebosz
  * @since 2.7
  *
  */
@@ -148,6 +154,7 @@ public RetryTopicConfiguration processAnnotation(String[] topics, Method method,
 				.setTopicSuffixingStrategy(annotation.topicSuffixingStrategy())
 				.sameIntervalTopicReuseStrategy(annotation.sameIntervalTopicReuseStrategy())
 				.timeoutAfter(timeout)
+				.dltRoutingRules(createDltRoutingSpecFromAnnotation(annotation.exceptionBasedDltRouting()))
 				.create(getKafkaTemplate(resolveExpressionAsString(annotation.kafkaTemplate(), "kafkaTemplate"), topics));
 	}
 
@@ -191,6 +198,11 @@ private SleepingBackOffPolicy<?> createBackoffFromAnnotation(Backoff backoff, Be
 		return policy;
 	}
 
+	private Map<String, Set<Class<? extends Throwable>>> createDltRoutingSpecFromAnnotation(ExceptionBasedDltRouting routingSpec) {
+		return Arrays.stream(routingSpec.routingRules())
+			.collect(Collectors.toMap(ExceptionBasedDestinationDlt::suffix, excBasedDestDlt -> Set.of(excBasedDestDlt.exceptions())));
+	}
+
 	private EndpointHandlerMethod getDltProcessor(Method listenerMethod, Object bean) {
 		Class<?> declaringClass = listenerMethod.getDeclaringClass();
 		return Arrays.stream(ReflectionUtils.getDeclaredMethods(declaringClass))

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/DefaultDestinationTopicResolver.java

@@ -49,6 +49,7 @@
  * @author Tomaz Fernandes
  * @author Gary Russell
  * @author Yvette Quinby
+ * @author Adrian Chlebosz
  * @since 2.7
  *
  */
@@ -174,11 +175,26 @@ private static boolean isMatchingDltTopic(DestinationTopic destination, Exceptio
 		}
 
 		boolean isDltIntendedForCurrentExc = destination.usedForExceptions().stream()
-			.anyMatch(excType -> excType.isInstance(e));
+			.anyMatch(excType -> isDirectExcOrCause(e, excType));
 		boolean isGenericPurposeDlt = destination.usedForExceptions().isEmpty();
 		return isDltIntendedForCurrentExc || isGenericPurposeDlt;
 	}
 
+	private static boolean isDirectExcOrCause(Exception e, Class<? extends Throwable> excType) {
+		Throwable toMatch = e;
+
+		boolean isMatched = excType.isInstance(toMatch);
+		while (!isMatched) {
+			toMatch = toMatch.getCause();
+			if (toMatch == null) {
+				return false;
+			}
+			isMatched = excType.isInstance(toMatch);
+		}
+
+		return isMatched;
+	}
+
 	@Override
 	public DestinationTopic getNextDestinationTopicFor(String mainListenerId, String topic) {
 		return getDestinationHolderFor(mainListenerId, topic).getNextDestination();

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/DestinationTopic.java

@@ -30,6 +30,7 @@
  *
  * @author Tomaz Fernandes
  * @author Gary Russell
+ * @author Adrian Chlebosz
  * @since 2.7
  *
  */
@@ -195,14 +196,15 @@ public Properties(Properties sourceProperties, String suffix, Type type) {
 		 * @param shouldRetryOn the exception classifications.
 		 * @param timeout the timeout.
 		 * @param autoStartDltHandler whether or not to start the DLT handler.
+		 * @param usedForExceptions the exceptions which destination is intended for
 		 * @since 2.8
 		 */
 		public Properties(long delayMs, String suffix, Type type,
 				int maxAttempts, int numPartitions,
 				DltStrategy dltStrategy,
 				KafkaOperations<?, ?> kafkaOperations,
 				BiPredicate<Integer, Throwable> shouldRetryOn, long timeout, @Nullable Boolean autoStartDltHandler,
-			  	Set<Class<? extends Throwable>> usedForExceptions) {
+				Set<Class<? extends Throwable>> usedForExceptions) {
 
 			this.delayMs = delayMs;
 			this.suffix = suffix;
@@ -248,6 +250,10 @@ public Boolean autoStartDltHandler() {
 			return this.autoStartDltHandler;
 		}
 
+		public Set<Class<? extends Throwable>> usedForExceptions() {
+			return this.usedForExceptions;
+		}
+
 		@Override
 		public boolean equals(Object o) {
 			if (this == o) {

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/DestinationTopicContainer.java

@@ -26,6 +26,7 @@
  *
  * @author Tomaz Fernandes
  * @author Gary Russell
+ * @author Adrian Chlebosz
  * @since 2.7
  */
 public interface DestinationTopicContainer {
@@ -65,9 +66,10 @@ public interface DestinationTopicContainer {
 	 * DLT for the given topic, or null if none is found.
 	 * @param mainListenerId the listener id.
 	 * @param topicName the topic name for which to look the DLT for
+	 * @param exc the exception which is being handled
 	 * @return The {@link DestinationTopic} instance corresponding to the DLT.
 	 */
 	@Nullable
-	DestinationTopic getDltFor(String mainListenerId, String topicName, Exception e);
+	DestinationTopic getDltFor(String mainListenerId, String topicName, Exception exc);
 
 }

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/DestinationTopicPropertiesFactory.java

@@ -17,22 +17,21 @@
 package org.springframework.kafka.retrytopic;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import java.util.function.BiPredicate;
 import java.util.stream.Collectors;
 import java.util.stream.IntStream;
+import java.util.stream.Stream;
 
 import org.springframework.classify.BinaryExceptionClassifier;
 import org.springframework.kafka.core.KafkaOperations;
 import org.springframework.kafka.retrytopic.DestinationTopic.Type;
 import org.springframework.lang.Nullable;
 import org.springframework.util.StringUtils;
 
-import java.util.Collections;
-import java.util.Map;
-import java.util.Set;
-import java.util.stream.Stream;
-
 /**
  *
  * Creates a list of {@link DestinationTopic.Properties} based on the
@@ -41,6 +40,7 @@
  * @author Tomaz Fernandes
  * @author Gary Russell
  * @author João Lima
+ * @author Adrian Chlebosz
  * @since 2.7
  *
  */
@@ -68,7 +68,7 @@ public class DestinationTopicPropertiesFactory {
 
 	private final long timeout;
 
-	private final Map<String, Set<Class<? extends Throwable>>> exceptionBasedRouting;
+	private final Map<String, Set<Class<? extends Throwable>>> dltRoutingRules;
 
 	@Nullable
 	private Boolean autoStartDltHandler;
@@ -85,6 +85,7 @@ public class DestinationTopicPropertiesFactory {
 	 * @param topicSuffixingStrategy the topic suffixing strategy.
 	 * @param sameIntervalTopicReuseStrategy the same interval reuse strategy.
 	 * @param timeout the timeout.
+	 * @param dltRoutingRules the specification of which DLT should be used for the particular exception type
 	 * @since 3.0.12
 	 */
 	public DestinationTopicPropertiesFactory(String retryTopicSuffix, String dltSuffix, List<Long> backOffValues,
@@ -94,7 +95,7 @@ public DestinationTopicPropertiesFactory(String retryTopicSuffix, String dltSuff
 			TopicSuffixingStrategy topicSuffixingStrategy,
 			SameIntervalTopicReuseStrategy sameIntervalTopicReuseStrategy,
 			long timeout,
-		 	Map<String, Set<Class<? extends Throwable>>> exceptionBasedRouting) {
+			Map<String, Set<Class<? extends Throwable>>> dltRoutingRules) {
 
 		this.dltStrategy = dltStrategy;
 		this.kafkaOperations = kafkaOperations;
@@ -104,7 +105,7 @@ public DestinationTopicPropertiesFactory(String retryTopicSuffix, String dltSuff
 		this.sameIntervalTopicReuseStrategy = sameIntervalTopicReuseStrategy;
 		this.timeout = timeout;
 		this.destinationTopicSuffixes = new DestinationTopicSuffixes(retryTopicSuffix, dltSuffix);
-		this.exceptionBasedRouting = exceptionBasedRouting;
+		this.dltRoutingRules = dltRoutingRules;
 		this.backOffValues = backOffValues;
 		// Max Attempts include the initial try.
 		this.maxAttempts = this.backOffValues.size() + 1;
@@ -132,7 +133,8 @@ private List<DestinationTopic.Properties> createPropertiesForFixedDelaySingleTop
 		DestinationTopic.Properties retryTopicProperties = createRetryProperties(1, getShouldRetryOn());
 		if (isNoDltStrategy()) {
 			return Arrays.asList(mainTopicProperties, retryTopicProperties);
-		} else {
+		}
+		else {
 			DestinationTopic.Properties dltProperties = createDltProperties();
 			List<DestinationTopic.Properties> customDltProperties = createCustomDltProperties();
 			return Stream.concat(
@@ -159,7 +161,10 @@ private List<DestinationTopic.Properties> createPropertiesForDefaultTopicStrateg
 			.mapToObj(this::createTopicProperties)
 			.collect(Collectors.toList());
 		if (!isNoDltStrategy()) {
-			basicProperties.addAll(createCustomDltProperties());
+			List<DestinationTopic.Properties> customDltProperties = createCustomDltProperties();
+			// add all custom DLTs properties before the generic purpose one to make sure that they are considered
+			// before the generic purpose one is considered and chosen
+			basicProperties.addAll(basicProperties.size() - 1, customDltProperties);
 		}
 
 		return basicProperties;
@@ -206,8 +211,8 @@ private DestinationTopic.Properties createDltProperties() {
 	}
 
 	private List<DestinationTopic.Properties> createCustomDltProperties() {
-		return exceptionBasedRouting.entrySet().stream()
-			.map(entry -> new DestinationTopic.Properties(0, entry.getKey() + "-" + this.destinationTopicSuffixes.getDltSuffix(),
+		return this.dltRoutingRules.entrySet().stream()
+			.map(entry -> new DestinationTopic.Properties(0, entry.getKey() + this.destinationTopicSuffixes.getDltSuffix(),
 				DestinationTopic.Type.DLT, this.maxAttempts, this.numPartitions, this.dltStrategy,
 				this.kafkaOperations, (a, e) -> false, this.timeout, this.autoStartDltHandler, entry.getValue()))
 			.toList();

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/ExceptionBasedDestinationDlt.java

@@ -1,6 +1,48 @@
+/*
+ * Copyright 2016-2023 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.kafka.retrytopic;
 
+/**
+ * Annotation allowing to specify additional DLT which will be chosen when message
+ * processing caused the configured exception to be thrown.
+ *
+ * @author Adrian Chlebosz
+ * @see org.springframework.kafka.retrytopic.ExceptionBasedDltRouting
+ * @since 3.1.1
+ */
 public @interface ExceptionBasedDestinationDlt {
-    String customSuffix();
-    Class<? extends Throwable>[] exceptions();
+
+	/**
+	 * Suffix extension used when constructing the name for the new DLT. It is placed
+	 * before the main suffix configured through the
+	 * ${@link org.springframework.kafka.annotation.RetryableTopic#dltTopicSuffix()}, so the
+	 * final name is the product of these two.
+	 *
+	 * @return the configured suffix extension
+	 */
+	String suffix();
+
+	/**
+	 * When message processing throws one of the exceptions configured here, then
+	 * it should be eventually redirected to the DLT with name containing the extension
+	 * configured through {@link #suffix()}. The causes of the thrown exception will be
+	 * traversed to match with any of configured ones.
+	 *
+	 * @return configured exceptions
+	 */
+	Class<? extends Throwable>[] exceptions();
 }

spring-kafka/src/main/java/org/springframework/kafka/retrytopic/ExceptionBasedDltRouting.java

@@ -1,5 +1,36 @@
+/*
+ * Copyright 2023 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.kafka.retrytopic;
 
+/**
+ * Annotation allowing to specify the custom DLT routing rules steered by exceptions
+ * which might be thrown during the processing.
+ *
+ * @author Adrian Chlebosz
+ * @see org.springframework.kafka.retrytopic.ExceptionBasedDestinationDlt
+ * @since 3.1.1
+ */
 public @interface ExceptionBasedDltRouting {
-    ExceptionBasedDestinationDlt[] routing() default {};
+
+	/**
+	 * Specific rules expressing to which custom DLT the message should be redirected
+	 * when the specified exception has been thrown during its processing.
+	 *
+	 * @return configured routing
+	 */
+	ExceptionBasedDestinationDlt[] routingRules() default {};
 }