From d73270025d82194301a8b10fd95016e37a1f4516 Mon Sep 17 00:00:00 2001
From: Christoph Strobl <christoph.strobl@broadcom.com>
Date: Tue, 28 Oct 2025 13:15:12 +0100
Subject: [PATCH] Deprecate background flag for creating indexes.

And fix type name in tests.

See #5074
Original pull request #5085
---
 .../data/mongodb/core/index/CompoundIndex.java             | 4 ++++
 .../org/springframework/data/mongodb/core/index/Index.java | 7 ++++++-
 .../springframework/data/mongodb/core/index/Indexed.java   | 4 ++++
 .../index/MongoPersistentEntityIndexResolverUnitTests.java | 6 +++---
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/CompoundIndex.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/CompoundIndex.java
index 05cf13f66..2f618386a 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/CompoundIndex.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/CompoundIndex.java
@@ -152,11 +152,15 @@ public @interface CompoundIndex {
 
 	/**
 	 * If {@literal true} the index will be created in the background.
+	 * <p>
+	 * <strong>NOTE:</strong> Since MongoDB 4.2 the background flag is ignored by the server if set.
 	 *
 	 * @return {@literal false} by default.
 	 * @see <a href=
 	 *      "https://docs.mongodb.org/manual/core/indexes/#background-construction">https://docs.mongodb.org/manual/core/indexes/#background-construction</a>
+	 * @deprecated since 5.0 for removal without replacement.
 	 */
+	@Deprecated(since = "5.0", forRemoval = true)
 	boolean background() default false;
 
 	/**
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Index.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Index.java
index 91195a40f..c6f83e2e7 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Index.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Index.java
@@ -94,10 +94,15 @@ public class Index implements IndexDefinition {
 
 	/**
 	 * Build the index in background (non blocking).
+	 * <p>
+	 * <strong>NOTE:</strong> Since MongoDB 4.2 the background flag is ignored by the server if set.
 	 *
 	 * @return this.
 	 * @since 1.5
-	 */@Contract("-> this")
+	 * @deprecated since 5.0 for removal without replacement.
+	 */
+	@Deprecated(since = "5.0", forRemoval = true)
+	@Contract("-> this")
 	public Index background() {
 
 		this.background = true;
diff --git a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java
index 0866556c1..de89420c8 100644
--- a/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java
+++ b/spring-data-mongodb/src/main/java/org/springframework/data/mongodb/core/index/Indexed.java
@@ -123,11 +123,15 @@ public @interface Indexed {
 
 	/**
 	 * If {@literal true} the index will be created in the background.
+	 * <p>
+	 * <strong>NOTE:</strong> Since MongoDB 4.2 the background flag is ignored by the server if set.
 	 *
 	 * @return {@literal false} by default.
+	 * @deprecated since 5.0 for removal without replacement.
 	 * @see <a href=
 	 *      "https://docs.mongodb.org/manual/core/indexes/#background-construction">https://docs.mongodb.org/manual/core/indexes/#background-construction</a>
 	 */
+	@Deprecated(since = "5.0", forRemoval = true)
 	boolean background() default false;
 
 	/**
diff --git a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java
index ba5446194..6b1ade323 100644
--- a/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java
+++ b/spring-data-mongodb/src/test/java/org/springframework/data/mongodb/core/index/MongoPersistentEntityIndexResolverUnitTests.java
@@ -670,7 +670,7 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 		public void compoundIndexDoesNotSpecifyNameWhenUsingGenerateName() {
 
 			List<IndexDefinitionHolder> indexDefinitions = prepareMappingContextAndResolveIndexForType(
-					ComountIndexWithAutogeneratedName.class);
+					CompoundIndexWithAutogeneratedName.class);
 
 			IndexDefinition indexDefinition = indexDefinitions.get(0).getIndexDefinition();
 			assertThat(indexDefinition.getIndexOptions())
@@ -835,10 +835,10 @@ public class MongoPersistentEntityIndexResolverUnitTests {
 
 		class IndexDefinedOnSuperClass extends CompoundIndexOnLevelZero {}
 
-		@Document("ComountIndexWithAutogeneratedName")
+		@Document("CompoundIndexWithAutogeneratedName")
 		@CompoundIndexes({ @CompoundIndex(useGeneratedName = true, def = "{'foo': 1, 'bar': -1}", background = true,
 				sparse = true, unique = true) })
-		class ComountIndexWithAutogeneratedName {}
+		class CompoundIndexWithAutogeneratedName {}
 
 		@Document("WithComposedAnnotation")
 		@ComposedCompoundIndex