Add Session.changeSessionId

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

@@ -455,6 +455,88 @@ public class RedisOperationsSessionRepositoryITests extends AbstractITests {
 		assertThat(findByPrincipalName.keySet()).containsOnly(toSave.getId());
 	}
 
+	@Test
+	public void changeSessionIdWhenOnlyChangeId() throws Exception {
+		String attrName = "changeSessionId";
+		String attrValue = "changeSessionId-value";
+		RedisSession toSave = this.repository.createSession();
+		toSave.setAttribute(attrName, attrValue);
+
+		this.repository.save(toSave);
+
+		RedisSession findById = this.repository.findById(toSave.getId());
+
+		assertThat(findById.<String>getAttribute(attrName)).isEqualTo(attrValue);
+
+		String originalFindById = findById.getId();
+		String changeSessionId = findById.changeSessionId();
+
+		this.repository.save(findById);
+
+		assertThat(this.repository.findById(originalFindById)).isNull();
+
+		RedisSession findByChangeSessionId = this.repository.findById(changeSessionId);
+
+		assertThat(findByChangeSessionId.<String>getAttribute(attrName)).isEqualTo(attrValue);
+	}
+
+	@Test
+	public void changeSessionIdWhenChangeTwice() throws Exception {
+		RedisSession toSave = this.repository.createSession();
+
+		this.repository.save(toSave);
+
+		String originalId = toSave.getId();
+		String changeId1 = toSave.changeSessionId();
+		String changeId2 = toSave.changeSessionId();
+
+		this.repository.save(toSave);
+
+		assertThat(this.repository.findById(originalId)).isNull();
+		assertThat(this.repository.findById(changeId1)).isNull();
+		assertThat(this.repository.findById(changeId2)).isNotNull();
+	}
+
+	@Test
+	public void changeSessionIdWhenSetAttributeOnChangedSession() throws Exception {
+		String attrName = "changeSessionId";
+		String attrValue = "changeSessionId-value";
+
+		RedisSession toSave = this.repository.createSession();
+
+		this.repository.save(toSave);
+
+		RedisSession findById = this.repository.findById(toSave.getId());
+
+		findById.setAttribute(attrName, attrValue);
+
+		String originalFindById = findById.getId();
+		String changeSessionId = findById.changeSessionId();
+
+		this.repository.save(findById);
+
+		assertThat(this.repository.findById(originalFindById)).isNull();
+
+		RedisSession findByChangeSessionId = this.repository.findById(changeSessionId);
+
+		assertThat(findByChangeSessionId.<String>getAttribute(attrName)).isEqualTo(attrValue);
+	}
+
+	@Test
+	public void changeSessionIdWhenHasNotSaved() throws Exception {
+		String attrName = "changeSessionId";
+		String attrValue = "changeSessionId-value";
+
+		RedisSession toSave = this.repository.createSession();
+		String originalId = toSave.getId();
+		toSave.changeSessionId();
+
+		this.repository.save(toSave);
+
+		assertThat(this.repository.findById(toSave.getId())).isNotNull();
+		assertThat(this.repository.findById(originalId)).isNull();
+	}
+
 	private String getSecurityName() {
 		return this.context.getAuthentication().getName();
 	}

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

@@ -675,6 +675,7 @@ public class RedisOperationsSessionRepository implements
 		private Map<String, Object> delta = new HashMap<>();
 		private boolean isNew;
 		private String originalPrincipalName;
+		private String originalSessionId;
 
 		/**
 		 * Creates a new instance ensuring to mark all of the new attributes to be
@@ -699,6 +700,7 @@ public class RedisOperationsSessionRepository implements
 			Assert.notNull(cached, "MapSession cannot be null");
 			this.cached = cached;
 			this.originalPrincipalName = PRINCIPAL_NAME_RESOLVER.resolvePrincipal(this);
+			this.originalSessionId = cached.getId();
 		}
 
 		public void setNew(boolean isNew) {
@@ -726,6 +728,10 @@ public class RedisOperationsSessionRepository implements
 			return this.cached.getId();
 		}
 
+		public String changeSessionId() {
+			return this.cached.changeSessionId();
+		}
+
 		public Instant getLastAccessedTime() {
 			return this.cached.getLastAccessedTime();
 		}
@@ -773,10 +779,11 @@ public class RedisOperationsSessionRepository implements
 		 * session.
 		 */
 		private void saveDelta() {
+			String sessionId = getId();
+			saveChangeSessionId(sessionId);
 			if (this.delta.isEmpty()) {
 				return;
 			}
-			String sessionId = getId();
 			getSessionBoundHashOperations(sessionId).putAll(this.delta);
 			String principalSessionKey = getSessionAttrNameKey(
 					FindByIndexNameSessionRepository.PRINCIPAL_NAME_INDEX_NAME);
@@ -806,6 +813,15 @@ public class RedisOperationsSessionRepository implements
 			RedisOperationsSessionRepository.this.expirationPolicy
 					.onExpirationUpdated(originalExpiration, this);
 		}
+
+		private void saveChangeSessionId(String sessionId) {
+			if (!isNew() && !sessionId.equals(this.originalSessionId)) {
+				String originalSessionIdKey = getSessionKey(this.originalSessionId);
+				String sessionIdKey = getSessionKey(sessionId);
+				RedisOperationsSessionRepository.this.sessionRedisOperations.rename(originalSessionIdKey, sessionIdKey);
+				this.originalSessionId = sessionId;
+			}
+		}
 	}
 
 	/**

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

@@ -131,6 +131,16 @@ public class RedisOperationsSessionRepositoryTests {
 		this.redisRepository.save(session);
 	}
 
+	@Test
+	public void changeSessionId() {
+		RedisSession createSession = this.redisRepository.createSession();
+		String originalId = createSession.getId();
+		String changeSessionId = createSession.changeSessionId();
+
+		assertThat(originalId).isNotEqualTo(changeSessionId);
+		assertThat(createSession.getId()).isEqualTo(createSession.getId());
+	}
+
 	@Test
 	public void createSessionDefaultMaxInactiveInterval() throws Exception {
 		Session session = this.redisRepository.createSession();