GH-2260: Reduce Header Constant Verbosity

Resolves #2260

**cherry-pick to main, removing 4 deprecated constants**

Author: garyrussell

spring-kafka-docs/src/main/asciidoc/kafka.adoc

@@ -275,8 +275,8 @@ Then, to use the template, you can invoke one of its methods.
 When you use the methods with a `Message<?>` parameter, the topic, partition, and key information is provided in a message header that includes the following items:
 
 * `KafkaHeaders.TOPIC`
-* `KafkaHeaders.PARTITION_ID`
-* `KafkaHeaders.MESSAGE_KEY`
+* `KafkaHeaders.PARTITION`
+* `KafkaHeaders.KEY`
 * `KafkaHeaders.TIMESTAMP`
 
 The message payload is the data.
@@ -831,7 +831,7 @@ In this example, we use the reply topic header from the request:
 public Message<?> messageReturn(String in) {
     return MessageBuilder.withPayload(in.toUpperCase())
             .setHeader(KafkaHeaders.TOPIC, replyTo)
-            .setHeader(KafkaHeaders.MESSAGE_KEY, 42)
+            .setHeader(KafkaHeaders.KEY, 42)
             .setHeader(KafkaHeaders.CORRELATION_ID, correlation)
             .build();
 }
@@ -850,7 +850,7 @@ It will also echo the incoming `KafkaHeaders.CORRELATION_ID` and `KafkaHeaders.R
 @SendTo  // default REPLY_TOPIC header
 public Message<?> messageReturn(String in) {
     return MessageBuilder.withPayload(in.toUpperCase())
-            .setHeader(KafkaHeaders.MESSAGE_KEY, 42)
+            .setHeader(KafkaHeaders.KEY, 42)
             .build();
 }
 ----
@@ -1474,13 +1474,13 @@ Finally, metadata about the record is available from message headers.
 You can use the following header names to retrieve the headers of the message:
 
 * `KafkaHeaders.OFFSET`
-* `KafkaHeaders.RECEIVED_MESSAGE_KEY`
+* `KafkaHeaders.RECEIVED_KEY`
 * `KafkaHeaders.RECEIVED_TOPIC`
-* `KafkaHeaders.RECEIVED_PARTITION_ID`
+* `KafkaHeaders.RECEIVED_PARTITION`
 * `KafkaHeaders.RECEIVED_TIMESTAMP`
 * `KafkaHeaders.TIMESTAMP_TYPE`
 
-Starting with version 2.5 the `RECEIVED_MESSAGE_KEY` is not present if the incoming record has a `null` key; previously the header was populated with a `null` value.
+Starting with version 2.5 the `RECEIVED_KEY` is not present if the incoming record has a `null` key; previously the header was populated with a `null` value.
 This change is to make the framework consistent with `spring-messaging` conventions where `null` valued headers are not present.
 
 The following example shows how to use the headers:
@@ -1490,8 +1490,8 @@ The following example shows how to use the headers:
 ----
 @KafkaListener(id = "qux", topicPattern = "myTopic1")
 public void listen(@Payload String foo,
-        @Header(name = KafkaHeaders.RECEIVED_MESSAGE_KEY, required = false) Integer key,
-        @Header(KafkaHeaders.RECEIVED_PARTITION_ID) int partition,
+        @Header(name = KafkaHeaders.RECEIVED_KEY, required = false) Integer key,
+        @Header(KafkaHeaders.RECEIVED_PARTITION) int partition,
         @Header(KafkaHeaders.RECEIVED_TOPIC) String topic,
         @Header(KafkaHeaders.RECEIVED_TIMESTAMP) long ts
         ) {
@@ -1558,8 +1558,8 @@ The following example shows how to use the headers:
 ----
 @KafkaListener(id = "list", topics = "myTopic", containerFactory = "batchFactory")
 public void listen(List<String> list,
-        @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) List<Integer> keys,
-        @Header(KafkaHeaders.RECEIVED_PARTITION_ID) List<Integer> partitions,
+        @Header(KafkaHeaders.RECEIVED_KEY) List<Integer> keys,
+        @Header(KafkaHeaders.RECEIVED_PARTITION) List<Integer> partitions,
         @Header(KafkaHeaders.RECEIVED_TOPIC) List<String> topics,
         @Header(KafkaHeaders.OFFSET) List<Long> offsets) {
     ...
@@ -2160,7 +2160,7 @@ public class MultiListenerSendTo {
     @KafkaHandler
     @SendTo("!{'annotated25reply2'}")
     public String bar(@Payload(required = false) KafkaNull nul,
-            @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) int key) {
+            @Header(KafkaHeaders.RECEIVED_KEY) int key) {
         ...
     }
 
@@ -2258,7 +2258,7 @@ public Message<?> listen(String in, @Header(KafkaHeaders.REPLY_TOPIC) byte[] rep
         @Header(KafkaHeaders.CORRELATION_ID) byte[] correlation) {
     return MessageBuilder.withPayload(in.toUpperCase())
             .setHeader(KafkaHeaders.TOPIC, replyTo)
-            .setHeader(KafkaHeaders.MESSAGE_KEY, 42)
+            .setHeader(KafkaHeaders.KEY, 42)
             .setHeader(KafkaHeaders.CORRELATION_ID, correlation)
             .setHeader("someOtherHeader", "someValue")
             .build();
@@ -4860,7 +4860,7 @@ The following example shows such a configuration:
 [source, java]
 ----
 @KafkaListener(id = "deletableListener", topics = "myTopic")
-public void listen(@Payload(required = false) String value, @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) String key) {
+public void listen(@Payload(required = false) String value, @Header(KafkaHeaders.RECEIVED_KEY) String key) {
     // value == null represents key deletion
 }
 ----
@@ -4887,7 +4887,7 @@ static class MultiListenerBean {
     }
 
     @KafkaHandler
-    public void delete(@Payload(required = false) KafkaNull nul, @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) int key) {
+    public void delete(@Payload(required = false) KafkaNull nul, @Header(KafkaHeaders.RECEIVED_KEY) int key) {
         ...
     }
 
@@ -4973,7 +4973,7 @@ public ConsumerAwareListenerErrorHandler listen3ErrorHandler() {
         MessageHeaders headers = m.getHeaders();
         c.seek(new org.apache.kafka.common.TopicPartition(
                 headers.get(KafkaHeaders.RECEIVED_TOPIC, String.class),
-                headers.get(KafkaHeaders.RECEIVED_PARTITION_ID, Integer.class)),
+                headers.get(KafkaHeaders.RECEIVED_PARTITION, Integer.class)),
                 headers.get(KafkaHeaders.OFFSET, Long.class));
         return null;
     };
@@ -4992,7 +4992,7 @@ public ConsumerAwareListenerErrorHandler listen10ErrorHandler() {
         this.listen10Exception = e;
         MessageHeaders headers = m.getHeaders();
         List<String> topics = headers.get(KafkaHeaders.RECEIVED_TOPIC, List.class);
-        List<Integer> partitions = headers.get(KafkaHeaders.RECEIVED_PARTITION_ID, List.class);
+        List<Integer> partitions = headers.get(KafkaHeaders.RECEIVED_PARTITION, List.class);
         List<Long> offsets = headers.get(KafkaHeaders.OFFSET, List.class);
         Map<TopicPartition, Long> offsetsToReset = new HashMap<>();
         for (int i = 0; i < topics.size(); i++) {
@@ -5549,8 +5549,8 @@ For POJO batch listeners, starting with version 2.8.6, the header is copied into
 @KafkaListener(id = "list2", topics = "someTopic", containerFactory = "batchFactory",
         info = "info for batch")
 public void listen(List<Thing> list,
-        @Header(KafkaHeaders.RECEIVED_MESSAGE_KEY) List<Integer> keys,
-        @Header(KafkaHeaders.RECEIVED_PARTITION_ID) List<Integer> partitions,
+        @Header(KafkaHeaders.RECEIVED_KEY) List<Integer> keys,
+        @Header(KafkaHeaders.RECEIVED_PARTITION) List<Integer> partitions,
         @Header(KafkaHeaders.RECEIVED_TOPIC) List<String> topics,
         @Header(KafkaHeaders.OFFSET) List<Long> offsets,
         @Header(KafkaHeaders.LISTENER_INFO) String info) {

spring-kafka/src/main/java/org/springframework/kafka/core/KafkaOperations.java

@@ -151,8 +151,8 @@ public interface KafkaOperations<K, V> {
 	 * @param message the message to send.
 	 * @return a Future for the {@link SendResult}.
 	 * @see org.springframework.kafka.support.KafkaHeaders#TOPIC
-	 * @see org.springframework.kafka.support.KafkaHeaders#PARTITION_ID
-	 * @see org.springframework.kafka.support.KafkaHeaders#MESSAGE_KEY
+	 * @see org.springframework.kafka.support.KafkaHeaders#PARTITION
+	 * @see org.springframework.kafka.support.KafkaHeaders#KEY
 	 */
 	ListenableFuture<SendResult<K, V>> send(Message<?> message);
 

spring-kafka/src/main/java/org/springframework/kafka/listener/adapter/MessagingMessageListenerAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -479,7 +479,7 @@ private Message<?> checkHeaders(Object result, String topic, Object source) { //
 		boolean needsTopic = headers.get(KafkaHeaders.TOPIC) == null;
 		boolean sourceIsMessage = source instanceof Message;
 		boolean needsCorrelation = headers.get(KafkaHeaders.CORRELATION_ID) == null && sourceIsMessage;
-		boolean needsPartition = headers.get(KafkaHeaders.PARTITION_ID) == null && sourceIsMessage
+		boolean needsPartition = headers.get(KafkaHeaders.PARTITION) == null && sourceIsMessage
 				&& getReplyPartition((Message<?>) source) != null;
 		if (needsTopic || needsCorrelation || needsPartition) {
 			MessageBuilder<?> builder = MessageBuilder.fromMessage(reply);
@@ -546,7 +546,7 @@ private void sendReplyForMessageSource(Object result, String topic, Object sourc
 	private void setPartition(MessageBuilder<?> builder, Message<?> source) {
 		byte[] partitionBytes = getReplyPartition(source);
 		if (partitionBytes != null) {
-			builder.setHeader(KafkaHeaders.PARTITION_ID, ByteBuffer.wrap(partitionBytes).getInt());
+			builder.setHeader(KafkaHeaders.PARTITION, ByteBuffer.wrap(partitionBytes).getInt());
 		}
 	}
 

spring-kafka/src/main/java/org/springframework/kafka/streams/messaging/MessagingTransformer.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2019-2021 the original author or authors.
+ * Copyright 2019-2022 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.
@@ -92,7 +92,7 @@ public KeyValue<K, R> transform(K key, V value) {
 				headers.add(header);
 			}
 		});
-		Object key2 = message.getHeaders().get(KafkaHeaders.MESSAGE_KEY);
+		Object key2 = message.getHeaders().get(KafkaHeaders.KEY);
 		return new KeyValue(key2 == null ? key : key2, message.getPayload());
 	}
 

spring-kafka/src/main/java/org/springframework/kafka/support/AbstractKafkaHeaderMapper.java

@@ -68,12 +68,12 @@ public AbstractKafkaHeaderMapper(String... patterns) {
 		this.matchers.add(new NeverMatchHeaderMatcher(
 				KafkaHeaders.ACKNOWLEDGMENT,
 				KafkaHeaders.CONSUMER,
-				KafkaHeaders.MESSAGE_KEY,
+				KafkaHeaders.KEY,
 				KafkaHeaders.OFFSET,
-				KafkaHeaders.PARTITION_ID,
+				KafkaHeaders.PARTITION,
 				KafkaHeaders.RAW_DATA,
-				KafkaHeaders.RECEIVED_MESSAGE_KEY,
-				KafkaHeaders.RECEIVED_PARTITION_ID,
+				KafkaHeaders.RECEIVED_KEY,
+				KafkaHeaders.RECEIVED_PARTITION,
 				KafkaHeaders.RECEIVED_TIMESTAMP,
 				KafkaHeaders.RECEIVED_TOPIC,
 				KafkaHeaders.TIMESTAMP,

spring-kafka/src/main/java/org/springframework/kafka/support/KafkaHeaders.java

@@ -41,14 +41,30 @@ public abstract class KafkaHeaders {
 	 */
 	public static final String TOPIC = PREFIX + "topic";
 
+	/**
+	 * The header containing the record key when sending data to Kafka.
+	 * @since 2.9
+	 */
+	public static final String KEY = PREFIX + "messageKey";
+
 	/**
 	 * The header containing the message key when sending data to Kafka.
+	 * @deprecated in favor of {@link #KEY}.
 	 */
+	@Deprecated
 	public static final String MESSAGE_KEY = PREFIX + "messageKey";
 
 	/**
 	 * The header containing the topic partition when sending data to Kafka.
+	 * @since 2.0
+	 */
+	public static final String PARTITION = PREFIX + "partitionId";
+
+	/**
+	 * The header containing the topic partition when sending data to Kafka.
+	 * @deprecated in favor of {@link #PARTITION}.
 	 */
+	@Deprecated
 	public static final String PARTITION_ID = PREFIX + "partitionId";
 
 	/**
@@ -83,17 +99,34 @@ public abstract class KafkaHeaders {
 	public static final String RECEIVED_TOPIC = RECEIVED + "Topic";
 
 	/**
-	 * The header containing the message key for the received message.
+	 * The header containing the record key from the received message.
+	 * @since 2.9
 	 */
+	public static final String RECEIVED_KEY = RECEIVED + "MessageKey";
+
+	/**
+	 * The header containing the record key from the received message.
+	 * @deprecated in favor of {@link #RECEIVED_KEY}.
+	 */
+	@Deprecated
 	public static final String RECEIVED_MESSAGE_KEY = RECEIVED + "MessageKey";
 
 	/**
-	 * The header containing the topic partition for the received message.
+	 * The header containing the topic partition from the received message.
+	 * @since 2.9
+	 */
+	public static final String RECEIVED_PARTITION = RECEIVED + "PartitionId";
+
+	/**
+	 * The header containing the topic partition from the received message.
+	 * @deprecated in favor of {@link #RECEIVED_PARTITION}.
 	 */
+	@Deprecated
 	public static final String RECEIVED_PARTITION_ID = RECEIVED + "PartitionId";
 
 	/**
-	 * The header for holding the {@link org.apache.kafka.common.record.TimestampType type} of timestamp.
+	 * The header for holding the {@link org.apache.kafka.common.record.TimestampType
+	 * type} of timestamp.
 	 */
 	public static final String TIMESTAMP_TYPE = PREFIX + "timestampType";
 

spring-kafka/src/main/java/org/springframework/kafka/support/converter/MessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2019 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -61,12 +61,12 @@ default void commonHeaders(Acknowledgment acknowledgment, Consumer<?, ?> consume
 			@Nullable Object timestampType, Object timestamp) {
 
 		rawHeaders.put(KafkaHeaders.RECEIVED_TOPIC, topic);
-		rawHeaders.put(KafkaHeaders.RECEIVED_PARTITION_ID, partition);
+		rawHeaders.put(KafkaHeaders.RECEIVED_PARTITION, partition);
 		rawHeaders.put(KafkaHeaders.OFFSET, offset);
 		rawHeaders.put(KafkaHeaders.TIMESTAMP_TYPE, timestampType);
 		rawHeaders.put(KafkaHeaders.RECEIVED_TIMESTAMP, timestamp);
 		JavaUtils.INSTANCE
-			.acceptIfNotNull(KafkaHeaders.RECEIVED_MESSAGE_KEY, theKey, (key, val) -> rawHeaders.put(key, val))
+			.acceptIfNotNull(KafkaHeaders.RECEIVED_KEY, theKey, (key, val) -> rawHeaders.put(key, val))
 			.acceptIfNotNull(KafkaHeaders.GROUP_ID, MessageConverter.getGroupId(),
 					(key, val) -> rawHeaders.put(key, val))
 			.acceptIfNotNull(KafkaHeaders.ACKNOWLEDGMENT, acknowledgment, (key, val) -> rawHeaders.put(key, val))

spring-kafka/src/main/java/org/springframework/kafka/support/converter/MessagingMessageConverter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2016-2021 the original author or authors.
+ * Copyright 2016-2022 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.
@@ -227,8 +227,8 @@ else if (topicHeader == null) {
 			throw new IllegalStateException(KafkaHeaders.TOPIC + " must be a String or byte[], not "
 					+ topicHeader.getClass());
 		}
-		Integer partition = headers.get(KafkaHeaders.PARTITION_ID, Integer.class);
-		Object key = headers.get(KafkaHeaders.MESSAGE_KEY);
+		Integer partition = headers.get(KafkaHeaders.PARTITION, Integer.class);
+		Object key = headers.get(KafkaHeaders.KEY);
 		Object payload = convertPayload(message);
 		Long timestamp = headers.get(KafkaHeaders.TIMESTAMP, Long.class);
 		Headers recordHeaders = initialRecordHeaders(message);

spring-kafka/src/test/java/org/springframework/kafka/annotation/BatchListenerConversionTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2017-2021 the original author or authors.
+ * Copyright 2017-2022 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.
@@ -266,7 +266,7 @@ public KafkaListenerContainerFactory<?> getContainerFactory() {
 				containerFactory = "#{__listener.containerFactory}")
 		// @SendTo("foo") test WARN log for void return
 		public void listen1(List<Foo> foos, @Header(KafkaHeaders.RECEIVED_TOPIC) List<String> topics,
-				@Header(KafkaHeaders.RECEIVED_PARTITION_ID) List<Integer> partitions) {
+				@Header(KafkaHeaders.RECEIVED_PARTITION) List<Integer> partitions) {
 			if (this.received == null) {
 				this.received = foos;
 			}
@@ -318,7 +318,7 @@ public Collection<Message<?>> listen1(List<Foo> foos) {
 			}
 			return foos.stream().map(f -> MessageBuilder.withPayload(new Foo(f.getBar().toUpperCase()))
 					.setHeader(KafkaHeaders.TOPIC, "blc5")
-					.setHeader(KafkaHeaders.MESSAGE_KEY, 42)
+					.setHeader(KafkaHeaders.KEY, 42)
 					.build())
 					.collect(Collectors.toList());
 		}