Add support for configuring custom IndexResolver

See: #1467

spring-session-data-redis/src/main/java/org/springframework/session/data/redis/RedisIndexedSessionRepository.java

@@ -280,8 +280,6 @@ public class RedisIndexedSessionRepository
 
 	private final RedisSessionExpirationPolicy expirationPolicy;
 
-	private final IndexResolver<RedisSession> indexResolver;
-
 	private ApplicationEventPublisher eventPublisher = (event) -> {
 	};
 
@@ -291,6 +289,8 @@ public class RedisIndexedSessionRepository
 	 */
 	private Integer defaultMaxInactiveInterval;
 
+	private IndexResolver<Session> indexResolver = new DelegatingIndexResolver<>(new PrincipalNameIndexResolver<>());
+
 	private RedisSerializer<Object> defaultSerializer = new JdkSerializationRedisSerializer();
 
 	private FlushMode flushMode = FlushMode.ON_SAVE;
@@ -307,7 +307,6 @@ public class RedisIndexedSessionRepository
 		this.sessionRedisOperations = sessionRedisOperations;
 		this.expirationPolicy = new RedisSessionExpirationPolicy(sessionRedisOperations, this::getExpirationsKey,
 				this::getSessionKey);
-		this.indexResolver = new DelegatingIndexResolver<>(new PrincipalNameIndexResolver<>());
 		configureSessionChannels();
 	}
 
@@ -334,6 +333,15 @@ public class RedisIndexedSessionRepository
 		this.defaultMaxInactiveInterval = defaultMaxInactiveInterval;
 	}
 
+	/**
+	 * Set the {@link IndexResolver} to use.
+	 * @param indexResolver the index resolver
+	 */
+	public void setIndexResolver(IndexResolver<Session> indexResolver) {
+		Assert.notNull(indexResolver, "indexResolver cannot be null");
+		this.indexResolver = indexResolver;
+	}
+
 	/**
 	 * Sets the default redis serializer. Replaces default serializer which is based on
 	 * {@link JdkSerializationRedisSerializer}.

spring-session-data-redis/src/main/java/org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfiguration.java

@@ -51,8 +51,10 @@ import org.springframework.scheduling.annotation.EnableScheduling;
 import org.springframework.scheduling.annotation.SchedulingConfigurer;
 import org.springframework.scheduling.config.ScheduledTaskRegistrar;
 import org.springframework.session.FlushMode;
+import org.springframework.session.IndexResolver;
 import org.springframework.session.MapSession;
 import org.springframework.session.SaveMode;
+import org.springframework.session.Session;
 import org.springframework.session.config.SessionRepositoryCustomizer;
 import org.springframework.session.config.annotation.web.http.SpringHttpSessionConfiguration;
 import org.springframework.session.data.redis.RedisFlushMode;
@@ -98,6 +100,8 @@ public class RedisHttpSessionConfiguration extends SpringHttpSessionConfiguratio
 
 	private RedisConnectionFactory redisConnectionFactory;
 
+	private IndexResolver<Session> indexResolver;
+
 	private RedisSerializer<Object> defaultRedisSerializer;
 
 	private ApplicationEventPublisher applicationEventPublisher;
@@ -117,6 +121,9 @@ public class RedisHttpSessionConfiguration extends SpringHttpSessionConfiguratio
 		RedisTemplate<Object, Object> redisTemplate = createRedisTemplate();
 		RedisIndexedSessionRepository sessionRepository = new RedisIndexedSessionRepository(redisTemplate);
 		sessionRepository.setApplicationEventPublisher(this.applicationEventPublisher);
+		if (this.indexResolver != null) {
+			sessionRepository.setIndexResolver(this.indexResolver);
+		}
 		if (this.defaultRedisSerializer != null) {
 			sessionRepository.setDefaultSerializer(this.defaultRedisSerializer);
 		}
@@ -216,6 +223,11 @@ public class RedisHttpSessionConfiguration extends SpringHttpSessionConfiguratio
 		this.applicationEventPublisher = applicationEventPublisher;
 	}
 
+	@Autowired(required = false)
+	public void setIndexResolver(IndexResolver<Session> indexResolver) {
+		this.indexResolver = indexResolver;
+	}
+
 	@Autowired(required = false)
 	@Qualifier("springSessionRedisTaskExecutor")
 	public void setRedisTaskExecutor(Executor redisTaskExecutor) {

spring-session-data-redis/src/test/java/org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfigurationTests.java

@@ -36,7 +36,9 @@ import org.springframework.data.redis.core.RedisOperations;
 import org.springframework.data.redis.listener.RedisMessageListenerContainer;
 import org.springframework.mock.env.MockEnvironment;
 import org.springframework.session.FlushMode;
+import org.springframework.session.IndexResolver;
 import org.springframework.session.SaveMode;
+import org.springframework.session.Session;
 import org.springframework.session.config.SessionRepositoryCustomizer;
 import org.springframework.session.data.redis.RedisFlushMode;
 import org.springframework.session.data.redis.RedisIndexedSessionRepository;
@@ -228,6 +230,17 @@ class RedisHttpSessionConfigurationTests {
 				.withMessageContaining("expected single matching bean but found 2");
 	}
 
+	@Test
+	void customIndexResolverConfiguration() {
+		registerAndRefresh(RedisConfig.class, CustomIndexResolverConfiguration.class);
+		RedisIndexedSessionRepository repository = this.context.getBean(RedisIndexedSessionRepository.class);
+		@SuppressWarnings("unchecked")
+		IndexResolver<Session> indexResolver = this.context.getBean(IndexResolver.class);
+		assertThat(repository).isNotNull();
+		assertThat(indexResolver).isNotNull();
+		assertThat(repository).hasFieldOrPropertyWithValue("indexResolver", indexResolver);
+	}
+
 	@Test // gh-1252
 	void customRedisMessageListenerContainerConfig() {
 		registerAndRefresh(RedisConfig.class, CustomRedisMessageListenerContainerConfig.class);
@@ -414,6 +427,18 @@ class RedisHttpSessionConfigurationTests {
 
 	}
 
+	@Configuration
+	@EnableRedisHttpSession
+	static class CustomIndexResolverConfiguration {
+
+		@Bean
+		@SuppressWarnings("unchecked")
+		public IndexResolver<Session> indexResolver() {
+			return mock(IndexResolver.class);
+		}
+
+	}
+
 	@Configuration
 	@EnableRedisHttpSession
 	static class CustomRedisMessageListenerContainerConfig {