Polishing.

Consistently use literal null.

See #3010

Author: mp911de

src/main/java/org/springframework/data/redis/cache/DefaultRedisCacheWriter.java

@@ -429,7 +429,7 @@ interface AsyncCacheWriter {
 		 * @param name the cache name from which to retrieve the cache entry.
 		 * @param key the cache entry key.
 		 * @param ttl optional TTL to set for Time-to-Idle eviction.
-		 * @return a future that completes either with a value if the value exists or completing with {@code null} if the
+		 * @return a future that completes either with a value if the value exists or completing with {@literal null} if the
 		 *         cache does not contain an entry.
 		 */
 		CompletableFuture<byte[]> retrieve(String name, byte[] key, @Nullable Duration ttl);

src/main/java/org/springframework/data/redis/cache/RedisCacheWriter.java

@@ -293,7 +293,7 @@ static TtlFunction persistent() {
 		 * persistent value that does not expire.
 		 *
 		 * @param key the cache key.
-		 * @param value the cache value. Can be {@code null} if the cache supports {@code null} value caching.
+		 * @param value the cache value. Can be {@literal null} if the cache supports {@literal null} value caching.
 		 * @return the computed {@link Duration time-to-live (TTL)}. Can be {@link Duration#ZERO} for persistent values
 		 *         (i.e. cache entry does not expire).
 		 */

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

@@ -289,7 +289,7 @@ default Mono<ByteBuffer> hGet(ByteBuffer key, ByteBuffer field) {
 
 	/**
 	 * 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}.
+	 * Absent field values are represented using {@literal null} in the resulting {@link List}.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param fields must not be {@literal null}.
@@ -306,7 +306,7 @@ default Mono<List<ByteBuffer>> hMGet(ByteBuffer key, Collection<ByteBuffer> fiel
 
 	/**
 	 * 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}.
+	 * Absent field values are represented using {@literal null} in the resulting {@link List}.
 	 *
 	 * @param commands must not be {@literal null}.
 	 * @return

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

@@ -350,7 +350,7 @@ default Mono<ByteBuffer> getSet(ByteBuffer key, ByteBuffer value) {
 
 	/**
 	 * 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}.
+	 * represented using {@literal null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
 	 * @return
@@ -365,7 +365,7 @@ default Mono<List<ByteBuffer>> mGet(List<ByteBuffer> keys) {
 
 	/**
 	 * 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}.
+	 * field values are represented using {@literal null} in the resulting {@link List}.
 	 *
 	 * @param keysets must not be {@literal null}.
 	 * @return

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

@@ -69,7 +69,7 @@ public interface RedisHashCommands {
 
 	/**
 	 * 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}.
+	 * field values are represented using {@literal null} in the resulting {@link List}.
 	 *
 	 * @param key must not be {@literal null}.
 	 * @param fields must not be {@literal empty}.

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

@@ -86,10 +86,10 @@ enum BitOperation {
 
 	/**
 	 * 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}.
+	 * {@literal null} in the resulting {@link List}.
 	 *
 	 * @param keys must not be {@literal null}.
-	 * @return {@code null} when used in pipeline / transaction.
+	 * @return {@literal 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/lettuce/LettuceFutureUtils.java

@@ -87,8 +87,8 @@ static <T> T join(CompletionStage<T> future) throws RuntimeException, Completion
 
 	/**
 	 * Returns a {@link Function} that ignores {@link CompletionStage#exceptionally(Function) exceptional completion} by
-	 * recovering to {@code null}. This allows to progress with a previously failed {@link CompletionStage} without regard
-	 * to the actual success/exception state.
+	 * recovering to {@literal null}. This allows to progress with a previously failed {@link CompletionStage} without
+	 * regard to the actual success/exception state.
 	 *
 	 * @return
 	 */

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

@@ -61,7 +61,7 @@ public interface BoundHashOperations<H, HK, HV> extends BoundKeyOperations<H> {
 
 	/**
 	 * 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}.
+	 * Absent field values are represented using {@literal 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

@@ -61,7 +61,7 @@ public interface HashOperations<H, HK, HV> {
 
 	/**
 	 * 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}.
+	 * Absent field values are represented using {@literal 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

@@ -28,8 +28,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Christoph Strobl
@@ -66,7 +66,7 @@ public interface ReactiveHashOperations<H, HK, HV> {
 
 	/**
 	 * 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}.
+	 * Absent field values are represented using {@literal 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/ReactiveListOperations.java

@@ -33,8 +33,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Christoph Strobl

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

@@ -45,8 +45,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Christoph Strobl

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

@@ -58,8 +58,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Christoph Strobl

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

@@ -27,8 +27,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Christoph Strobl

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

@@ -30,8 +30,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Jiahe Cai
@@ -162,7 +162,7 @@ public interface ReactiveValueOperations<K, V> {
 
 	/**
 	 * 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}.
+	 * {@literal 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/ReactiveZSetOperations.java

@@ -37,8 +37,8 @@
  * <p>
  * Streams of methods returning {@code Mono<K>} or {@code Flux<M>} are terminated with
  * {@link org.springframework.dao.InvalidDataAccessApiUsageException} when
- * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@code null} for a
- * particular element as Reactive Streams prohibit the usage of {@code null} values.
+ * {@link org.springframework.data.redis.serializer.RedisElementReader#read(ByteBuffer)} returns {@literal null} for a
+ * particular element as Reactive Streams prohibit the usage of {@literal null} values.
  *
  * @author Mark Paluch
  * @author Christoph Strobl

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

@@ -32,13 +32,13 @@ public interface RedisCallback<T> {
 	/**
 	 * Method called by {@link RedisTemplate} with an active {@link RedisConnection}.
 	 * <p>
-	 * Callback code need not care about activating/opening or closing the {@link RedisConnection},
-	 * nor handling {@link Exception exceptions}.
+	 * Callback code need not care about activating/opening or closing the {@link RedisConnection}, nor handling
+	 * {@link Exception exceptions}.
 	 *
 	 * @param connection active {@link RedisConnection Redis connection}.
-	 * @return the {@link Object result} of the operation performed in the callback or {@code null}.
+	 * @return the {@link Object result} of the operation performed in the callback or {@literal null}.
 	 * @throws DataAccessException if the operation performed by the callback fails to execute in the context of Redis
-	 * using the given {@link RedisConnection}.
+	 *           using the given {@link RedisConnection}.
 	 */
 	@Nullable
 	T doInRedis(RedisConnection connection) throws DataAccessException;

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

@@ -587,7 +587,7 @@ public RedisConnection getRequiredConnection() {
 		 * Override the existing {@link RedisConnection} handle with the given {@link RedisConnection}. Reset the handle if
 		 * given {@literal null}.
 		 * <p>
-		 * Used for releasing the Connection on suspend (with a {@code null} argument) and setting a fresh Connection on
+		 * Used for releasing the Connection on suspend (with a {@literal null} argument) and setting a fresh Connection on
 		 * resume.
 		 */
 		protected void setConnection(@Nullable RedisConnection connection) {

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

@@ -74,7 +74,7 @@ public ScanCursor(long cursorId) {
 	 * Crates new {@link ScanCursor}
 	 *
 	 * @param cursorId the cursor Id.
-	 * @param options Defaulted to {@link ScanOptions#NONE} if {@code null}.
+	 * @param options Defaulted to {@link ScanOptions#NONE} if {@literal null}.
 	 */
 	public ScanCursor(long cursorId, @Nullable ScanOptions options) {
 
@@ -100,7 +100,7 @@ private void scan(long cursorId) {
 
 	/**
 	 * Performs the actual scan command using the native client implementation. The given {@literal options} are never
-	 * {@code null}.
+	 * {@literal null}.
 	 *
 	 * @param cursorId
 	 * @param options

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

@@ -264,7 +264,7 @@ default Boolean setIfPresent(K key, V value, Duration timeout) {
 
 	/**
 	 * 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}.
+	 * {@literal 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/convert/Bucket.java

@@ -108,10 +108,10 @@ public byte[] get(String path) {
 	}
 
 	/**
-	 * Return whether {@code path} is associated with a non-{@code null} value.
+	 * Return whether {@code path} is associated with a non-{@literal null} value.
 	 *
 	 * @param path must not be {@literal null} or {@link String#isEmpty()}.
-	 * @return {@literal true} if the {@code path} is associated with a non-{@code null} value.
+	 * @return {@literal true} if the {@code path} is associated with a non-{@literal null} value.
 	 * @since 2.5
 	 */
 	public boolean hasValue(String path) {

src/test/java/org/springframework/data/redis/test/condition/RedisConditions.java

@@ -65,7 +65,7 @@ private RedisConditions(RedisClusterCommands<String, String> commands) {
 	/**
 	 * Create {@link RedisCommands} given {@link StatefulRedisConnection}.
 	 *
-	 * @param connection must not be {@code null}.
+	 * @param connection must not be {@literal null}.
 	 * @return
 	 */
 	public static RedisConditions of(StatefulRedisConnection<String, String> connection) {
@@ -75,7 +75,7 @@ public static RedisConditions of(StatefulRedisConnection<String, String> connect
 	/**
 	 * Create {@link RedisCommands} given {@link StatefulRedisClusterConnection}.
 	 *
-	 * @param connection must not be {@code null}.
+	 * @param connection must not be {@literal null}.
 	 * @return
 	 */
 	public static RedisConditions of(StatefulRedisClusterConnection<String, String> connection) {
@@ -85,7 +85,7 @@ public static RedisConditions of(StatefulRedisClusterConnection<String, String>
 	/**
 	 * Create {@link RedisConditions} given {@link RedisCommands}.
 	 *
-	 * @param commands must not be {@code null}.
+	 * @param commands must not be {@literal null}.
 	 * @return
 	 */
 	public static RedisConditions of(RedisClusterCommands<String, String> commands) {