Session creation with pre-specified id.

spring-session-core/src/main/java/org/springframework/session/CreateWithIdSessionRepository.java

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2014-2019 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.session;
+
+import org.springframework.lang.Nullable;
+
+/**
+ * Extends a basic {@link SessionRepository} to allow creating session with specific id.
+ *
+ * @param <S> the type of Session being managed by this
+ * {@link CreateWithIdSessionRepository}
+ * @author Jakub Maciej
+ */
+public interface CreateWithIdSessionRepository<S extends Session> extends SessionRepository<S> {
+
+	/**
+	 * Creates a new {@link Session} that is capable of being persisted by this
+	 * {@link SessionRepository}.
+	 *
+	 * <p>
+	 * This allows optimizations and customizations in how the {@link Session} is
+	 * persisted. For example, the implementation returned might keep track of the changes
+	 * ensuring that only the delta needs to be persisted on a save.
+	 * </p>
+	 * @param id a desired session id, if id is null - it will be generated by underlying
+	 * implementation
+	 * @return a new {@link Session} that is capable of being persisted by this
+	 * {@link SessionRepository}
+	 */
+	S createSession(@Nullable String id);
+
+}

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

@@ -21,6 +21,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 
 import org.apache.commons.logging.Log;
@@ -36,6 +37,7 @@
 import org.springframework.data.redis.core.RedisOperations;
 import org.springframework.data.redis.serializer.JdkSerializationRedisSerializer;
 import org.springframework.data.redis.serializer.RedisSerializer;
+import org.springframework.session.CreateWithIdSessionRepository;
 import org.springframework.session.DelegatingIndexResolver;
 import org.springframework.session.FindByIndexNameSessionRepository;
 import org.springframework.session.FlushMode;
@@ -244,10 +246,12 @@
  *
  * @author Rob Winch
  * @author Vedran Pavic
+ * @author Jakub Maciej
  * @since 2.2.0
  */
 public class RedisIndexedSessionRepository
-		implements FindByIndexNameSessionRepository<RedisIndexedSessionRepository.RedisSession>, MessageListener {
+		implements FindByIndexNameSessionRepository<RedisIndexedSessionRepository.RedisSession>,
+		CreateWithIdSessionRepository<RedisIndexedSessionRepository.RedisSession>, MessageListener {
 
 	private static final Log logger = LogFactory.getLog(RedisIndexedSessionRepository.class);
 
@@ -489,7 +493,12 @@ public void deleteById(String sessionId) {
 
 	@Override
 	public RedisSession createSession() {
-		MapSession cached = new MapSession();
+		return createSession(null);
+	}
+
+	@Override
+	public RedisSession createSession(final String id) {
+		MapSession cached = Optional.ofNullable(id).map(MapSession::new).orElse(new MapSession());
 		if (this.defaultMaxInactiveInterval != null) {
 			cached.setMaxInactiveInterval(Duration.ofSeconds(this.defaultMaxInactiveInterval));
 		}

spring-session-data-redis/src/test/java/org/springframework/session/data/redis/RedisIndexedSessionRepositoryTests.java

@@ -162,6 +162,19 @@ void createSessionCustomMaxInactiveInterval() {
 		assertThat(session.getMaxInactiveInterval()).isEqualTo(Duration.ofSeconds(interval));
 	}
 
+	@Test
+	void createSessionWithSpecificId() {
+		final String desiredSessionId = "desiredId";
+		Session session = this.redisRepository.createSession(desiredSessionId);
+		assertThat(session.getId()).isEqualTo(desiredSessionId);
+	}
+
+	@Test
+	void createSessionWithIdEqualNull() {
+		Session session = this.redisRepository.createSession(null);
+		assertThat(session.getId()).isNotNull();
+	}
+
 	@Test
 	void saveNewSession() {
 		RedisSession session = this.redisRepository.createSession();

spring-session-hazelcast/src/main/java/org/springframework/session/hazelcast/HazelcastIndexedSessionRepository.java

@@ -22,6 +22,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.TimeUnit;
 
@@ -39,6 +40,7 @@
 import org.apache.commons.logging.LogFactory;
 
 import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.session.CreateWithIdSessionRepository;
 import org.springframework.session.DelegatingIndexResolver;
 import org.springframework.session.FindByIndexNameSessionRepository;
 import org.springframework.session.FlushMode;
@@ -108,10 +110,12 @@
  * @author Tommy Ludwig
  * @author Mark Anderson
  * @author Aleksandar Stojsavljevic
+ * @author Jakub Maciej
  * @since 2.2.0
  */
 public class HazelcastIndexedSessionRepository
 		implements FindByIndexNameSessionRepository<HazelcastIndexedSessionRepository.HazelcastSession>,
+		CreateWithIdSessionRepository<HazelcastIndexedSessionRepository.HazelcastSession>,
 		EntryAddedListener<String, MapSession>, EntryEvictedListener<String, MapSession>,
 		EntryRemovedListener<String, MapSession> {
 
@@ -234,7 +238,12 @@ public void setSaveMode(SaveMode saveMode) {
 
 	@Override
 	public HazelcastSession createSession() {
-		MapSession cached = new MapSession();
+		return createSession(null);
+	}
+
+	@Override
+	public HazelcastSession createSession(final String id) {
+		MapSession cached = Optional.ofNullable(id).map(MapSession::new).orElse(new MapSession());
 		if (this.defaultMaxInactiveInterval != null) {
 			cached.setMaxInactiveInterval(Duration.ofSeconds(this.defaultMaxInactiveInterval));
 		}

spring-session-hazelcast/src/test/java/org/springframework/session/hazelcast/HazelcastIndexedSessionRepositoryTests.java

@@ -115,6 +115,27 @@ void createSessionCustomMaxInactiveInterval() {
 		verifyZeroInteractions(this.sessions);
 	}
 
+	@Test
+	void createSessionWithSpecificId() {
+		verify(this.sessions, times(1)).addEntryListener(any(MapListener.class), anyBoolean());
+
+		final String desiredSessionId = "desiredId";
+		HazelcastSession session = this.repository.createSession(desiredSessionId);
+
+		assertThat(session.getId()).isEqualTo(desiredSessionId);
+		verifyZeroInteractions(this.sessions);
+	}
+
+	@Test
+	void createSessionWithIdEqualNull() {
+		verify(this.sessions, times(1)).addEntryListener(any(MapListener.class), anyBoolean());
+
+		HazelcastSession session = this.repository.createSession(null);
+
+		assertThat(session.getId()).isNotNull();
+		verifyZeroInteractions(this.sessions);
+	}
+
 	@Test
 	void saveNewFlushModeOnSave() {
 		verify(this.sessions, times(1)).addEntryListener(any(MapListener.class), anyBoolean());

spring-session-jdbc/src/main/java/org/springframework/session/jdbc/JdbcIndexedSessionRepository.java

@@ -26,6 +26,7 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.Set;
 import java.util.UUID;
 import java.util.function.Supplier;
@@ -45,6 +46,7 @@
 import org.springframework.jdbc.core.ResultSetExtractor;
 import org.springframework.jdbc.support.lob.DefaultLobHandler;
 import org.springframework.jdbc.support.lob.LobHandler;
+import org.springframework.session.CreateWithIdSessionRepository;
 import org.springframework.session.DelegatingIndexResolver;
 import org.springframework.session.FindByIndexNameSessionRepository;
 import org.springframework.session.FlushMode;
@@ -125,10 +127,12 @@
  *
  * @author Vedran Pavic
  * @author Craig Andrews
+ * @author Jakub Maciej
  * @since 2.2.0
  */
 public class JdbcIndexedSessionRepository
-		implements FindByIndexNameSessionRepository<JdbcIndexedSessionRepository.JdbcSession> {
+		implements FindByIndexNameSessionRepository<JdbcIndexedSessionRepository.JdbcSession>,
+		CreateWithIdSessionRepository<JdbcIndexedSessionRepository.JdbcSession> {
 
 	/**
 	 * The default name of database table used by Spring Session to store sessions.
@@ -395,7 +399,12 @@ public void setSaveMode(SaveMode saveMode) {
 
 	@Override
 	public JdbcSession createSession() {
-		MapSession delegate = new MapSession();
+		return createSession(null);
+	}
+
+	@Override
+	public JdbcSession createSession(final String id) {
+		MapSession delegate = Optional.ofNullable(id).map(MapSession::new).orElse(new MapSession());
 		if (this.defaultMaxInactiveInterval != null) {
 			delegate.setMaxInactiveInterval(Duration.ofSeconds(this.defaultMaxInactiveInterval));
 		}

spring-session-jdbc/src/test/java/org/springframework/session/jdbc/JdbcIndexedSessionRepositoryTests.java

@@ -267,6 +267,23 @@ void createSessionImmediateFlushMode() {
 		verifyNoMoreInteractions(this.jdbcOperations);
 	}
 
+	@Test
+	void createSessionWithSpecificId() {
+		final String desiredSessionId = "desiredId";
+		JdbcSession session = this.repository.createSession(desiredSessionId);
+		assertThat(session.isNew()).isTrue();
+		assertThat(session.getId()).isEqualTo(desiredSessionId);
+		verifyNoMoreInteractions(this.jdbcOperations);
+	}
+
+	@Test
+	void createSessionWithIdEqualNull() {
+		JdbcSession session = this.repository.createSession(null);
+		assertThat(session.isNew()).isTrue();
+		assertThat(session.getId()).isNotNull();
+		verifyNoMoreInteractions(this.jdbcOperations);
+	}
+
 	@Test
 	void saveNewWithoutAttributes() {
 		JdbcSession session = this.repository.createSession();