Refine HMGET and MGET documentation.

Closes #2309

Author: mp911de

src/main/java/org/springframework/data/redis/connection/ReactiveHashCommands.java

@@ -288,7 +288,8 @@ default Mono<ByteBuffer> hGet(ByteBuffer key, ByteBuffer field) {
 	}
 
 	/**
-	 * Get values for given {@literal fields} from hash at {@literal key}.
+	 * Get values for given {@literal fields} from hash at {@literal key}. Values are in the order of the requested keys.
+	 * Absent field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param fields must not be {@literal null}.
@@ -304,7 +305,8 @@ default Mono<List<ByteBuffer>> hMGet(ByteBuffer key, Collection<ByteBuffer> fiel
 	}
 
 	/**
-	 * Get values for given {@literal fields} from hash at {@literal key}.
+	 * Get values for given {@literal fields} from hash at {@literal key}. Values are in the order of the requested keys.
+	 * Absent field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param commands must not be {@literal null}.
 	 * @return

src/main/java/org/springframework/data/redis/connection/ReactiveStringCommands.java

@@ -349,7 +349,8 @@ default Mono<ByteBuffer> getSet(ByteBuffer key, ByteBuffer value) {
 	Flux<ByteBufferResponse<SetCommand>> getSet(Publisher<SetCommand> commands);
 
 	/**
-	 * Get multiple values in one batch.
+	 * Get multiple values in one batch. Values are in the order of the requested keys. Absent field values are
+	 * represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
 	 * @return
@@ -363,7 +364,8 @@ default Mono<List<ByteBuffer>> mGet(List<ByteBuffer> keys) {
 	}
 
 	/**
-	 * Get multiple values at for {@literal keysets} in batches.
+	 * Get multiple values at for {@literal keysets} in batches. Values are in the order of the requested keys. Absent
+	 * field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param keysets must not be {@literal null}.
 	 * @return

src/main/java/org/springframework/data/redis/connection/RedisHashCommands.java

@@ -68,11 +68,12 @@ public interface RedisHashCommands {
 	byte[] hGet(byte[] key, byte[] field);
 
 	/**
-	 * Get values for given {@code fields} from hash at {@code key}.
+	 * Get values for given {@code fields} from hash at {@code key}. Values are in the order of the requested keys Absent
+	 * field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param fields must not be {@literal empty}.
-	 * @return empty {@link List} if key or fields do not exists. {@literal null} when used in pipeline / transaction.
+	 * @return empty {@link List} if key does not exist. {@literal null} when used in pipeline / transaction.
 	 * @see <a href="https://redis.io/commands/hmget">Redis Documentation: HMGET</a>
 	 */
 	@Nullable

src/main/java/org/springframework/data/redis/connection/RedisStringCommands.java

@@ -85,10 +85,11 @@ enum BitOperation {
 	byte[] getSet(byte[] key, byte[] value);
 
 	/**
-	 * Get multiple {@code keys}. Values are returned in the order of the requested keys.
+	 * Get multiple {@code keys}. Values are in the order of the requested keys Absent field values are represented using
+	 * {@code null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
-	 * @return empty {@link List} if keys do not exist or when used in pipeline / transaction.
+	 * @return {@code null} when used in pipeline / transaction.
 	 * @see <a href="https://redis.io/commands/mget">Redis Documentation: MGET</a>
 	 */
 	@Nullable

src/main/java/org/springframework/data/redis/connection/StringRedisConnection.java

@@ -437,7 +437,7 @@ interface StringTuple extends Tuple {
 	String getSet(String key, String value);
 
 	/**
-	 * Get multiple {@code keys}. Values are returned in the order of the requested keys.
+	 * Get multiple {@code keys}. Values are in the order of the requested keys.
 	 *
 	 * @param keys must not be {@literal null}.
 	 * @return

src/main/java/org/springframework/data/redis/core/BoundHashOperations.java

@@ -60,7 +60,8 @@ public interface BoundHashOperations<H, HK, HV> extends BoundKeyOperations<H> {
 	HV get(Object member);
 
 	/**
-	 * Get values for given {@code keys} from the hash at the bound key.
+	 * Get values for given {@code keys} from the hash at the bound key. Values are in the order of the requested keys
+	 * Absent field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
 	 * @return {@literal null} when used in pipeline / transaction.

src/main/java/org/springframework/data/redis/core/HashOperations.java

@@ -60,7 +60,8 @@ public interface HashOperations<H, HK, HV> {
 	HV get(H key, Object hashKey);
 
 	/**
-	 * Get values for given {@code hashKeys} from hash at {@code key}.
+	 * Get values for given {@code hashKeys} from hash at {@code key}. Values are in the order of the requested keys
+	 * Absent field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param hashKeys must not be {@literal null}.

src/main/java/org/springframework/data/redis/core/ReactiveHashOperations.java

@@ -59,7 +59,8 @@ public interface ReactiveHashOperations<H, HK, HV> {
 	Mono<HV> get(H key, Object hashKey);
 
 	/**
-	 * Get values for given {@code hashKeys} from hash at {@code key}.
+	 * Get values for given {@code hashKeys} from hash at {@code key}. Values are in the order of the requested keys.
+	 * Absent field values are represented using {@code null} in the resulting {@link List}.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param hashKeys must not be {@literal null}.
@@ -122,10 +123,10 @@ public interface ReactiveHashOperations<H, HK, HV> {
 	Flux<HK> randomKeys(H key, long count);
 
 	/**
-	 * Return random entries from the hash stored at {@code key}. If the provided {@code count} argument is
-	 * positive, return a list of distinct entries, capped either at {@code count} or the hash size. If {@code count} is
-	 * negative, the behavior changes and the command is allowed to return the same entry multiple times. In this case,
-	 * the number of returned fields is the absolute value of the specified count.
+	 * Return random entries from the hash stored at {@code key}. If the provided {@code count} argument is positive,
+	 * return a list of distinct entries, capped either at {@code count} or the hash size. If {@code count} is negative,
+	 * the behavior changes and the command is allowed to return the same entry multiple times. In this case, the number
+	 * of returned fields is the absolute value of the specified count.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param count number of fields to return.

src/main/java/org/springframework/data/redis/core/ReactiveValueOperations.java

@@ -155,7 +155,8 @@ public interface ReactiveValueOperations<K, V> {
 	Mono<V> getAndSet(K key, V value);
 
 	/**
-	 * Get multiple {@code keys}. Values are returned in the order of the requested keys.
+	 * Get multiple {@code keys}. Values are in the order of the requested keys. Absent field values are represented using
+	 * {@code null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
 	 * @see <a href="https://redis.io/commands/mget">Redis Documentation: MGET</a>

src/main/java/org/springframework/data/redis/core/ValueOperations.java

@@ -263,7 +263,8 @@ default Boolean setIfPresent(K key, V value, Duration timeout) {
 	V getAndSet(K key, V value);
 
 	/**
-	 * Get multiple {@code keys}. Values are returned in the order of the requested keys.
+	 * Get multiple {@code keys}. Values are in the order of the requested keys Absent field values are represented using
+	 * {@code null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
 	 * @return {@literal null} when used in pipeline / transaction.