refactor: Redis를 사용하여 채팅 고도화하기

Related to: Issue #6

build.gradle

@@ -48,14 +48,12 @@ dependencies {
     runtimeOnly 'com.mysql:mysql-connector-j'
 	//redis
 	implementation 'org.springframework.boot:spring-boot-starter-data-redis'
+	//embedded redis - https://mvnrepository.com/artifact/it.ozimov/embedded-redis
+//	implementation 'it.ozimov:embedded-redis:0.7.2'
 	//lombok
 	compileOnly 'org.projectlombok:lombok'
 	annotationProcessor 'org.projectlombok:lombok'
 	testImplementation 'org.springframework.boot:spring-boot-starter-test'
-
-
-// https://mvnrepository.com/artifact/it.ozimov/embedded-redis
-	compileOnly 'it.ozimov:embedded-redis:0.7.2'
 }
 
 tasks.named('test') {

src/main/java/com/kusitms/jipbap/JipbapApplication.java

@@ -3,9 +3,7 @@
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
 import org.springframework.data.jpa.repository.config.EnableJpaAuditing;
-import org.springframework.data.redis.repository.configuration.EnableRedisRepositories;
 import org.springframework.scheduling.annotation.EnableScheduling;
-import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
 
 @EnableScheduling
 @EnableJpaAuditing

src/main/java/com/kusitms/jipbap/message/ChatController.java

@@ -13,25 +13,38 @@
 public class ChatController {
 
 //    private final ChatService chatService;
-    private final SimpMessageSendingOperations messagingTemplate;
+//    private final SimpMessageSendingOperations messagingTemplate;
+    private final RedisPublisher redisPublisher;
+    private final ChatRoomRepository chatRoomRepository;
 
 //    @PostMapping
 //    public ChatRoom createRoom(@RequestParam String name) {
 //        return chatService.createRoom(name);
 //    }
-//
+
 //    @GetMapping
 //    public List<ChatRoom> findAllRoom() {
 //        return chatService.findAllRoom();
 //    }
 //    package com.websocket.chat.controller;
 
+//    @MessageMapping("/chat/message")
+//    public void message(ChatMessage message) {
+//        if (ChatMessage.MessageType.JOIN.equals(message.getType()))
+//            message.setMessage(message.getSender() + "님이 입장하셨습니다.");
+//        messagingTemplate.convertAndSend("/sub/chat/room/" + message.getRoomId(), message); // sub/chat/room/{roomId} 경로로 메세지를 보낸다.
+//    }
 
+    /**
+     * websocket "/pub/chat/message"로 들어오는 메시징을 처리한다.
+     */
     @MessageMapping("/chat/message")
     public void message(ChatMessage message) {
-        if (ChatMessage.MessageType.JOIN.equals(message.getType()))
+        if (ChatMessage.MessageType.ENTER.equals(message.getType())) {
+            chatRoomRepository.enterChatRoom(message.getRoomId());
             message.setMessage(message.getSender() + "님이 입장하셨습니다.");
-        messagingTemplate.convertAndSend("/sub/chat/room/" + message.getRoomId(), message); // sub/chat/room/{roomId} 경로로 메세지를 보낸다.
+        }
+        // Websocket에 발행된 메시지를 redis로 발행한다(publish)
+        redisPublisher.publish(chatRoomRepository.getTopic(message.getRoomId()), message);
     }
-
 }

src/main/java/com/kusitms/jipbap/message/ChatMessage.java

@@ -8,7 +8,7 @@
 public class ChatMessage {
     // 메시지 타입 : 입장, 채팅
     public enum MessageType {
-        JOIN, TALK
+        ENTER, TALK
     }
     private MessageType type; // 메시지 타입
     private String roomId; // 방번호

src/main/java/com/kusitms/jipbap/message/ChatRoom.java

@@ -5,13 +5,17 @@
 import lombok.Setter;
 import org.springframework.web.socket.WebSocketSession;
 
+import java.io.Serial;
+import java.io.Serializable;
 import java.util.HashSet;
 import java.util.Set;
 import java.util.UUID;
 
 @Getter
 @Setter
-public class ChatRoom {
+public class ChatRoom implements Serializable {
+
+    private static final long serialVersionUID = 4780475579618133057L;
     private String roomId;
     private String name;
 

src/main/java/com/kusitms/jipbap/message/ChatRoomRepository.java

@@ -1,34 +1,71 @@
 package com.kusitms.jipbap.message;
 
 import jakarta.annotation.PostConstruct;
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.redis.core.HashOperations;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.listener.ChannelTopic;
+import org.springframework.data.redis.listener.RedisMessageListenerContainer;
 import org.springframework.stereotype.Repository;
 
-import java.util.*;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
 
+/**
+ * HGET CHAT_ROOM(key) aeif-4ifehw-2ef-4g5(room id) value(chatroom)
+ * redis hash의
+ */
+@RequiredArgsConstructor
 @Repository
 public class ChatRoomRepository {
-
-    private Map<String, ChatRoom> chatRoomMap;
+    // 채팅방(topic)에 발행되는 메시지를 처리할 Listener
+    private final RedisMessageListenerContainer redisMessageListener;
+    // 구독 처리 서비스
+    private final RedisSubscriber redisSubscriber;
+    // Redis
+    private static final String CHAT_ROOMS = "CHAT_ROOM";
+    private final RedisTemplate<String, Object> redisTemplate;
+    private HashOperations<String, String, ChatRoom> opsHashChatRoom;
+    // 채팅방의 대화 메시지를 발행하기 위한 redis topic 정보. 서버별로 채팅방에 매치되는 topic정보를 Map에 넣어 roomId로 찾을수 있도록 한다.
+    private Map<String, ChannelTopic> topics;
 
     @PostConstruct
     private void init() {
-        chatRoomMap = new LinkedHashMap<>();
+        opsHashChatRoom = redisTemplate.opsForHash();
+        topics = new HashMap<>();
     }
 
     public List<ChatRoom> findAllRoom() {
-        // 채팅방 생성순서 최근 순으로 반환
-        List chatRooms = new ArrayList<>(chatRoomMap.values());
-        Collections.reverse(chatRooms);
-        return chatRooms;
+        return opsHashChatRoom.values(CHAT_ROOMS);
     }
 
     public ChatRoom findRoomById(String id) {
-        return chatRoomMap.get(id);
+        return opsHashChatRoom.get(CHAT_ROOMS, id);
     }
 
+    /**
+     * 채팅방 생성 : 서버간 채팅방 공유를 위해 redis hash에 저장한다.
+     */
     public ChatRoom createChatRoom(String name) {
         ChatRoom chatRoom = ChatRoom.create(name);
-        chatRoomMap.put(chatRoom.getRoomId(), chatRoom);
+        opsHashChatRoom.put(CHAT_ROOMS, chatRoom.getRoomId(), chatRoom);
         return chatRoom;
     }
+
+    /**
+     * 채팅방 입장 : redis에 topic을 만들고 pub/sub 통신을 하기 위해 리스너를 설정한다.
+     */
+    public void enterChatRoom(String roomId) {
+        ChannelTopic topic = topics.get(roomId);
+        if (topic == null) {
+            topic = new ChannelTopic(roomId);
+            redisMessageListener.addMessageListener(redisSubscriber, topic);
+            topics.put(roomId, topic);
+        }
+    }
+
+    public ChannelTopic getTopic(String roomId) {
+        return topics.get(roomId);
+    }
 }

src/main/java/com/kusitms/jipbap/message/RedisConfig.java

@@ -0,0 +1,30 @@
+package com.kusitms.jipbap.message;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.data.redis.connection.RedisConnectionFactory;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.listener.RedisMessageListenerContainer;
+import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
+import org.springframework.data.redis.serializer.StringRedisSerializer;
+
+@Configuration
+public class RedisConfig {
+
+    //redis pub/sub을 처리하는 Listener
+    @Bean
+    public RedisMessageListenerContainer redisMessageListener(RedisConnectionFactory connectionFactory) {
+        RedisMessageListenerContainer container = new RedisMessageListenerContainer();
+        container.setConnectionFactory(connectionFactory);
+        return container;
+    }
+
+    @Bean
+    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
+        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
+        redisTemplate.setConnectionFactory(connectionFactory);
+        redisTemplate.setKeySerializer(new StringRedisSerializer());
+        redisTemplate.setValueSerializer(new Jackson2JsonRedisSerializer<>(String.class));
+        return redisTemplate;
+    }
+}

src/main/java/com/kusitms/jipbap/message/RedisPublisher.java

@@ -0,0 +1,19 @@
+package com.kusitms.jipbap.message;
+
+import lombok.RequiredArgsConstructor;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.data.redis.listener.ChannelTopic;
+import org.springframework.stereotype.Service;
+
+/**
+ * 메세지를 redis topic에 publish해주는 서비스
+ */
+@RequiredArgsConstructor
+@Service
+public class RedisPublisher {
+    private final RedisTemplate<String, Object> redisTemplate;
+
+    public void publish(ChannelTopic topic, ChatMessage message) {
+        redisTemplate.convertAndSend(topic.getTopic(), message);
+    }
+}

src/main/java/com/kusitms/jipbap/message/RedisSubscriber.java

@@ -0,0 +1,38 @@
+package com.kusitms.jipbap.message;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.data.redis.connection.Message;
+import org.springframework.data.redis.connection.MessageListener;
+import org.springframework.data.redis.core.RedisTemplate;
+import org.springframework.messaging.simp.SimpMessageSendingOperations;
+import org.springframework.stereotype.Service;
+
+@Slf4j
+@RequiredArgsConstructor
+@Service
+public class RedisSubscriber implements MessageListener {
+
+    private final ObjectMapper objectMapper;
+    private final RedisTemplate redisTemplate;
+    private final SimpMessageSendingOperations messagingTemplate;
+
+    /**
+     * RedisPublisher에서 pub된 메세지를 대기하고 있던 onMessage가 받아 처리한다.
+     * messagingTemplate을 사용하여 subscriber에게 메세지를 전달한다.
+     */
+    @Override
+    public void onMessage(Message message, byte[] pattern) {
+        try {
+            // redis에서 발행된 데이터를 받아 deserialize
+            String publishMessage = (String) redisTemplate.getStringSerializer().deserialize(message.getBody());
+            // ChatMessage 객채로 맵핑
+            ChatMessage roomMessage = objectMapper.readValue(publishMessage, ChatMessage.class);
+            // Websocket 구독자에게 채팅 메시지 Send
+            messagingTemplate.convertAndSend("/sub/chat/room/" + roomMessage.getRoomId(), roomMessage);
+        } catch (Exception e) {
+            log.error(e.getMessage());
+        }
+    }
+}

src/main/java/com/kusitms/jipbap/message/WebSockConfig.java

@@ -21,6 +21,6 @@ public void configureMessageBroker(MessageBrokerRegistry config) {
     public void registerStompEndpoints(StompEndpointRegistry registry) {
         registry.addEndpoint("/ws-stomp") //websocket 연결 endpoint
                 .setAllowedOriginPatterns("*");
-//                .withSockJS(); //제거시 endpoint 연결 성공
+//                .withSockJS(); //제거해야 endpoint 연결 성공
     }
 }

src/main/java/com/kusitms/jipbap/message/deprecated/EmbeddedRedisConfig.java

@@ -0,0 +1,31 @@
+//package com.kusitms.jipbap.message;
+//
+//import jakarta.annotation.PostConstruct;
+//import jakarta.annotation.PreDestroy;
+//import org.springframework.beans.factory.annotation.Value;
+//import org.springframework.context.annotation.Configuration;
+//import redis.embedded.RedisServer;
+//
+//@Configuration
+//public class EmbeddedRedisConfig {
+//
+//    @Value("${spring.data.redis.port}")
+//    private int redisPort;
+//
+//    private RedisServer redisServer;
+//
+//    @PostConstruct
+//    public void redisServer() {
+//        redisServer = RedisServer.builder()
+//                        .port(6380)
+//                        .build();
+//        redisServer.start(); //doesn't work in macos 14 sonoma
+//    }
+//
+//    @PreDestroy
+//    public void stopRedis() {
+//        if (redisServer != null) {
+//            redisServer.stop();
+//        }
+//    }
+//}