pokev25 · October 19, 2016 04:29 · Oct 19, 2016
diff --git a/RedisUserSessionRegistry.java b/RedisUserSessionRegistry.java
@@ -0,0 +1,77 @@
+import java.util.Set;
+
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.core.BoundHashOperations;
+import org.springframework.data.redis.core.BoundSetOperations;
+import org.springframework.data.redis.core.RedisOperations;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.core.StringRedisTemplate;
+import org.springframework.data.redis.serializer.StringRedisSerializer;
+import org.springframework.messaging.simp.user.UserSessionRegistry;
+import org.springframework.util.Assert;
+
+/**
+ * An implementation of {@link UserSessionRegistry} backed by Redis.
+ * @author thanh
+ */
+public class RedisUserSessionRegistry implements UserSessionRegistry {
+
+    /**
+     * The prefix for each key of the Redis Set representing a user's sessions. The suffix is the unique user id.
+     */
+    static final String BOUNDED_HASH_KEY_PREFIX = "spring:websockets:users:";
+
+    private final RedisOperations<String, String> sessionRedisOperations;
+
+    @SuppressWarnings("unchecked")
+    public RedisUserSessionRegistry(RedisConnectionFactory redisConnectionFactory) {
+        this(createDefaultTemplate(redisConnectionFactory));
+    }
+
+    public RedisUserSessionRegistry(RedisOperations<String, String> sessionRedisOperations) {
+        Assert.notNull(sessionRedisOperations, "sessionRedisOperations cannot be null");
+        this.sessionRedisOperations = sessionRedisOperations;
+    }
+
+    @Override
+    public Set<String> getSessionIds(String user) {
+        Set<String> entries = getSessionBoundHashOperations(user).members();
+        return (entries != null) ? entries : Collections.<String>emptySet();
+    }
+
+    @Override
+    public void registerSessionId(String user, String sessionId) {
+        getSessionBoundHashOperations(user).add(sessionId);
+    }
+
+    @Override
+    public void unregisterSessionId(String user, String sessionId) {
+        getSessionBoundHashOperations(user).remove(sessionId);
+    }
+
+    /**
+     * Gets the {@link BoundHashOperations} to operate on a username
+     */
+    private BoundSetOperations<String, String> getSessionBoundHashOperations(String username) {
+        String key = getKey(username);
+        return this.sessionRedisOperations.boundSetOps(key);
+    }
+
+    /**
+     * Gets the Hash key for this user by prefixing it appropriately.
+     */
+    static String getKey(String username) {
+        return BOUNDED_HASH_KEY_PREFIX + username;
+    }
+
+    @SuppressWarnings("rawtypes")
+    private static RedisTemplate createDefaultTemplate(RedisConnectionFactory connectionFactory) {
+        Assert.notNull(connectionFactory, "connectionFactory cannot be null");
+        StringRedisTemplate template = new StringRedisTemplate(connectionFactory);
+        template.setKeySerializer(new StringRedisSerializer());
+        template.setValueSerializer(new StringRedisSerializer());
+        template.afterPropertiesSet();
+        return template;
+    }
+
+}
diff --git a/WebSocketConfig.java b/WebSocketConfig.java
@@ -0,0 +1,24 @@
+// http://stackoverflow.com/questions/26853745/spring-websocket-in-a-tomcat-cluster
+public class WebSocketConfig extends AbstractWebSocketMessageBrokerConfigurer {
+
+    ...
+
+    @Autowired
+    private RedisConnectionFactory redisConnectionFactory;
+
+    @Override
+    public void configureMessageBroker(MessageBrokerRegistry config) {
+        config.enableStompBrokerRelay("/topic", "/queue")
+            .setRelayHost("localhost") // broker host
+            .setRelayPort(61613) // broker port
+            ;
+        config.setApplicationDestinationPrefixes("/app");
+    }
+
+    @Bean
+    public UserSessionRegistry userSessionRegistry() {
+        return new RedisUserSessionRegistry(redisConnectionFactory);
+    }
+
+    ...
+}