Add nullability annotations to module/spring-boot-data-mongodb

See gh-46587

module/spring-boot-data-mongodb/build.gradle

@@ -32,6 +32,7 @@ dependencies {
 	api("org.springframework.data:spring-data-mongodb")
 
 	compileOnly("com.fasterxml.jackson.core:jackson-annotations")
+	compileOnly("com.google.code.findbugs:jsr305")
 
 	optional(project(":core:spring-boot-autoconfigure"))
 	optional(project(":module:spring-boot-health"))

module/spring-boot-data-mongodb/src/main/java/org/springframework/boot/data/mongodb/autoconfigure/MongoDatabaseFactoryConfiguration.java

@@ -27,6 +27,7 @@ import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mongodb.MongoDatabaseFactory;
 import org.springframework.data.mongodb.core.MongoDatabaseFactorySupport;
 import org.springframework.data.mongodb.core.SimpleMongoClientDatabaseFactory;
+import org.springframework.util.Assert;
 
 /**
  * Configuration for a {@link MongoDatabaseFactory}.
@@ -49,6 +50,7 @@ class MongoDatabaseFactoryConfiguration {
 		if (database == null) {
 			database = connectionDetails.getConnectionString().getDatabase();
 		}
+		Assert.hasText(database, "Database name must not be empty");
 		return new SimpleMongoClientDatabaseFactory(mongoClient, database);
 	}
 

module/spring-boot-data-mongodb/src/main/java/org/springframework/boot/data/mongodb/autoconfigure/MongoDatabaseFactoryDependentConfiguration.java

@@ -19,6 +19,7 @@ package org.springframework.boot.data.mongodb.autoconfigure;
 import com.mongodb.ClientSessionOptions;
 import com.mongodb.client.ClientSession;
 import com.mongodb.client.MongoDatabase;
+import org.jspecify.annotations.Nullable;
 
 import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
 import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
@@ -112,7 +113,7 @@ class MongoDatabaseFactoryDependentConfiguration {
 			return this.mongoDatabaseFactory.withSession(session);
 		}
 
-		private String getGridFsDatabase(MongoConnectionDetails connectionDetails) {
+		private @Nullable String getGridFsDatabase(MongoConnectionDetails connectionDetails) {
 			return (connectionDetails.getGridFs() != null) ? connectionDetails.getGridFs().getDatabase() : null;
 		}
 

module/spring-boot-data-mongodb/src/main/java/org/springframework/boot/data/mongodb/autoconfigure/MongoReactiveDataAutoConfiguration.java

@@ -24,6 +24,7 @@ import com.mongodb.reactivestreams.client.MongoClient;
 import com.mongodb.reactivestreams.client.MongoDatabase;
 import org.bson.codecs.Codec;
 import org.bson.codecs.configuration.CodecRegistry;
+import org.jspecify.annotations.Nullable;
 import reactor.core.publisher.Mono;
 
 import org.springframework.boot.autoconfigure.AutoConfiguration;
@@ -50,6 +51,7 @@ import org.springframework.data.mongodb.core.convert.MappingMongoConverter;
 import org.springframework.data.mongodb.core.convert.MongoConverter;
 import org.springframework.data.mongodb.gridfs.ReactiveGridFsOperations;
 import org.springframework.data.mongodb.gridfs.ReactiveGridFsTemplate;
+import org.springframework.util.Assert;
 import org.springframework.util.StringUtils;
 
 /**
@@ -87,6 +89,7 @@ public final class MongoReactiveDataAutoConfiguration {
 		if (database == null) {
 			database = this.connectionDetails.getConnectionString().getDatabase();
 		}
+		Assert.hasText(database, "Database name must not be empty");
 		return new SimpleReactiveMongoDatabaseFactory(mongo, database);
 	}
 
@@ -143,7 +146,7 @@ public final class MongoReactiveDataAutoConfiguration {
 			return this.delegate.getMongoDatabase();
 		}
 
-		private String getGridFsDatabase(MongoConnectionDetails connectionDetails) {
+		private @Nullable String getGridFsDatabase(MongoConnectionDetails connectionDetails) {
 			return (connectionDetails.getGridFs() != null) ? connectionDetails.getGridFs().getDatabase() : null;
 		}
 

module/spring-boot-data-mongodb/src/main/java/org/springframework/boot/data/mongodb/autoconfigure/health/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for Spring Data MongoDB health.
  */
+@NullMarked
 package org.springframework.boot.data.mongodb.autoconfigure.health;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-data-mongodb/src/main/java/org/springframework/boot/data/mongodb/autoconfigure/package-info.java

@@ -17,4 +17,7 @@
 /**
  * Auto-configuration for Spring Data MongoDB.
  */
+@NullMarked
 package org.springframework.boot.data.mongodb.autoconfigure;
+
+import org.jspecify.annotations.NullMarked;

module/spring-boot-data-mongodb/src/main/java/org/springframework/boot/data/mongodb/health/package-info.java

@@ -17,4 +17,7 @@
 /**
  * MongoDB health integration using Spring Data MongoDB.
  */
+@NullMarked
 package org.springframework.boot.data.mongodb.health;
+
+import org.jspecify.annotations.NullMarked;