서버가 클라이언트에게 Ping/Pong 요청

backend/ddang/src/main/java/com/ddang/ddang/chat/domain/WebSocketSessions.java

@@ -7,11 +7,12 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.USER_ID;
+
 @Getter
 public class WebSocketSessions {
 
     protected static final String CHAT_ROOM_ID_KEY = "chatRoomId";
-    private static final String USER_ID_KEY = "userId";
 
     private final Set<WebSocketSession> sessions = Collections.newSetFromMap(new ConcurrentHashMap<>());
 
@@ -24,7 +25,7 @@ public void putIfAbsent(final WebSocketSession session, final Long chatRoomId) {
 
     public boolean contains(final Long userId) {
         return sessions.stream()
-                       .anyMatch(session -> session.getAttributes().get(USER_ID_KEY) == userId);
+                       .anyMatch(session -> session.getAttributes().get(USER_ID.getName()) == userId);
     }
 
     public void remove(final WebSocketSession session) {

backend/ddang/src/main/java/com/ddang/ddang/chat/handler/ChatWebSocketHandleTextMessageProvider.java

@@ -16,16 +16,25 @@
 import com.fasterxml.jackson.core.JsonProcessingException;
 import com.fasterxml.jackson.databind.ObjectMapper;
 import lombok.RequiredArgsConstructor;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.context.ApplicationEventPublisher;
+import org.springframework.scheduling.annotation.Scheduled;
 import org.springframework.stereotype.Component;
+import org.springframework.web.socket.PingMessage;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 
+import java.io.IOException;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import java.util.stream.Collectors;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.USER_ID;
+
+@Slf4j
 @Component
 @RequiredArgsConstructor
 public class ChatWebSocketHandleTextMessageProvider implements WebSocketHandleTextMessageProvider {
@@ -115,7 +124,7 @@ private TextMessage createTextMessage(
     }
 
     private boolean isMyMessage(final WebSocketSession session, final Long writerId) {
-        final long userId = Long.parseLong(String.valueOf(session.getAttributes().get("userId")));
+        final long userId = Long.parseLong(String.valueOf(session.getAttributes().get(USER_ID.getName())));
 
         return writerId.equals(userId);
     }
@@ -136,6 +145,39 @@ private void updateReadMessageLog(
 
     @Override
     public void remove(final WebSocketSession session) {
+        log.info("{} 연결 종료", session);
         sessions.remove(session);
     }
+
+    @Scheduled(fixedDelay = 60000)
+    public void sendPingSessions() {
+        final Set<WebSocketSession> webSocketSessions = getWebSocketSessions();
+
+        webSocketSessions.parallelStream()
+                         .forEach(this::sendPingMessage);
+    }
+
+    private Set<WebSocketSession> getWebSocketSessions() {
+        return sessions.getChatRoomSessions()
+                       .values()
+                       .stream()
+                       .flatMap(webSocketSessions -> webSocketSessions.getSessions().stream())
+                       .collect(Collectors.toSet());
+    }
+
+    private void sendPingMessage(final WebSocketSession session) {
+        final Map<String, Object> attributes = session.getAttributes();
+        final boolean connected = (boolean) attributes.get(CONNECTED.getName());
+        if (!connected) {
+            sessions.remove(session);
+            return;
+        }
+
+        attributes.put(CONNECTED.getName(), false);
+        try {
+            session.sendMessage(new PingMessage());
+        } catch (IOException e) {
+            log.error("ping 보내기 실패 : {} ", session);
+        }
+    }
 }

backend/ddang/src/main/java/com/ddang/ddang/websocket/configuration/WebSocketInterceptor.java

@@ -14,6 +14,10 @@
 
 import java.util.Map;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.BASE_URL;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.USER_ID;
+
 @Component
 @RequiredArgsConstructor
 public class WebSocketInterceptor extends HttpSessionHandshakeInterceptor {
@@ -27,8 +31,9 @@ public boolean beforeHandshake(
             final WebSocketHandler wsHandler,
             final Map<String, Object> attributes
     ) throws Exception {
-        attributes.put("userId", findUserId(request));
-        attributes.put("baseUrl", ImageRelativeUrl.USER.calculateAbsoluteUrl());
+        attributes.put(USER_ID.getName(), findUserId(request));
+        attributes.put(BASE_URL.getName(), ImageRelativeUrl.USER.calculateAbsoluteUrl());
+        attributes.put(CONNECTED.getName(), true);
 
         return super.beforeHandshake(request, response, wsHandler, attributes);
     }

backend/ddang/src/main/java/com/ddang/ddang/websocket/handler/WebSocketHandler.java

@@ -7,26 +7,29 @@
 import lombok.RequiredArgsConstructor;
 import org.springframework.stereotype.Component;
 import org.springframework.web.socket.CloseStatus;
+import org.springframework.web.socket.PongMessage;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 import org.springframework.web.socket.handler.TextWebSocketHandler;
 
 import java.util.List;
+import java.util.Map;
+
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.TYPE;
 
 @Component
 @RequiredArgsConstructor
 public class WebSocketHandler extends TextWebSocketHandler {
 
-    private static final String TYPE_KEY = "type";
-
     private final WebSocketHandleTextMessageProviderComposite providerComposite;
     private final ObjectMapper objectMapper;
 
     @Override
     protected void handleTextMessage(final WebSocketSession session, final TextMessage message) throws Exception {
         final String payload = message.getPayload();
         final TextMessageDto textMessageDto = objectMapper.readValue(payload, TextMessageDto.class);
-        session.getAttributes().put(TYPE_KEY, textMessageDto.type());
+        session.getAttributes().put(TYPE.getName(), textMessageDto.type());
 
         final WebSocketHandleTextMessageProvider provider = providerComposite.findProvider(textMessageDto.type());
         final List<SendMessageDto> sendMessageDtos = provider.handleCreateSendMessage(session, textMessageDto.data());
@@ -38,9 +41,15 @@ protected void handleTextMessage(final WebSocketSession session, final TextMessa
 
     @Override
     public void afterConnectionClosed(final WebSocketSession session, final CloseStatus status) {
-        final String type = String.valueOf(session.getAttributes().get(TYPE_KEY));
+        final String type = String.valueOf(session.getAttributes().get(TYPE.getName()));
         final TextMessageType textMessageType = TextMessageType.valueOf(type);
         final WebSocketHandleTextMessageProvider provider = providerComposite.findProvider(textMessageType);
         provider.remove(session);
     }
+
+    @Override
+    public void handlePongMessage(WebSocketSession session, PongMessage message) {
+        final Map<String, Object> attributes = session.getAttributes();
+        attributes.put(CONNECTED.getName(), true);
+    }
 }

backend/ddang/src/main/java/com/ddang/ddang/websocket/handler/dto/WebSocketAttributeKey.java

@@ -0,0 +1,18 @@
+package com.ddang.ddang.websocket.handler.dto;
+
+import lombok.Getter;
+
+@Getter
+public enum WebSocketAttributeKey {
+
+    USER_ID("userId"),
+    BASE_URL("baseUrl"),
+    CONNECTED("connected"),
+    TYPE("type");
+
+    private final String name;
+
+    WebSocketAttributeKey(final String name) {
+        this.name = name;
+    }
+}

backend/ddang/src/test/java/com/ddang/ddang/chat/domain/fixture/WebSocketSessionsTestFixture.java

@@ -3,10 +3,16 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.BASE_URL;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.USER_ID;
+
 @SuppressWarnings("NonAsciiCharacters")
 public class WebSocketSessionsTestFixture {
 
     protected Long 사용자_아이디 = 1L;
-    protected Map<String, Object> 세션_attribute_정보 = new HashMap<>(Map.of("userId", 사용자_아이디, "baseUrl", "/images"));
+    protected Map<String, Object> 세션_attribute_정보 = new HashMap<>(
+            Map.of(USER_ID.getName(), 사용자_아이디, BASE_URL.getName(), "/images", CONNECTED.getName(), true)
+    );
     protected Long 채팅방_아이디 = 1L;
 }

backend/ddang/src/test/java/com/ddang/ddang/chat/handler/ChatWebSocketHandleTextMessageProviderTest.java

@@ -3,6 +3,7 @@
 import com.ddang.ddang.chat.application.event.MessageNotificationEvent;
 import com.ddang.ddang.chat.application.event.UpdateReadMessageLogEvent;
 import com.ddang.ddang.chat.domain.WebSocketChatSessions;
+import com.ddang.ddang.chat.domain.WebSocketSessions;
 import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
 import com.ddang.ddang.chat.handler.fixture.ChatWebSocketHandleTextMessageProviderTestFixture;
 import com.ddang.ddang.configuration.IsolateDatabase;
@@ -22,16 +23,22 @@
 import org.springframework.boot.test.mock.mockito.SpyBean;
 import org.springframework.test.context.event.ApplicationEvents;
 import org.springframework.test.context.event.RecordApplicationEvents;
+import org.springframework.web.socket.PingMessage;
 import org.springframework.web.socket.WebSocketSession;
 
+import java.io.IOException;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.BDDMockito.given;
 import static org.mockito.BDDMockito.willDoNothing;
 import static org.mockito.BDDMockito.willReturn;
+import static org.mockito.Mockito.never;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
 
 @IsolateDatabase
 @RecordApplicationEvents
@@ -48,6 +55,9 @@ class ChatWebSocketHandleTextMessageProviderTest extends ChatWebSocketHandleText
     @SpyBean
     WebSocketChatSessions sessions;
 
+    @SpyBean
+    WebSocketSessions webSocketSessions;
+
     @Mock
     WebSocketSession writerSession;
 
@@ -186,4 +196,35 @@ class ChatWebSocketHandleTextMessageProviderTest extends ChatWebSocketHandleText
         final boolean actual = sessions.containsByUserId(채팅방.getId(), 발신자.getId());
         assertThat(actual).isFalse();
     }
+
+    @Test
+    void 저장되어_있는_세션에_ping_메시지를_보낸다() throws IOException {
+        // given
+        given(writerSession.getAttributes()).willReturn(발신자_세션_attribute_정보);
+        given(webSocketSessions.getSessions()).willReturn(Set.of(writerSession));
+        given(sessions.getChatRoomSessions()).willReturn(Map.of(채팅방.getId(), webSocketSessions));
+
+        // when
+        provider.sendPingSessions();
+
+        // then
+        verify(sessions, never()).remove(writerSession);
+        verify(writerSession, times(1)).sendMessage(new PingMessage());
+    }
+
+    @Test
+    void 연결이_끊긴_세션은_삭제한다() throws IOException {
+        // given
+        given(writerSession.getAttributes()).willReturn(연결이_끊긴_세션_attribute_정보);
+        given(webSocketSessions.getSessions()).willReturn(Set.of(writerSession));
+        given(sessions.getChatRoomSessions()).willReturn(Map.of(채팅방.getId(), webSocketSessions));
+        willDoNothing().given(sessions).remove(writerSession);
+
+        // when
+        provider.sendPingSessions();
+
+        // then
+        verify(sessions, times(1)).remove(writerSession);
+        verify(writerSession, never()).sendMessage(new PingMessage());
+    }
 }

backend/ddang/src/test/java/com/ddang/ddang/chat/handler/fixture/ChatWebSocketHandleTextMessageProviderTestFixture.java

@@ -10,7 +10,6 @@
 import com.ddang.ddang.chat.application.event.CreateReadMessageLogEvent;
 import com.ddang.ddang.chat.domain.ChatRoom;
 import com.ddang.ddang.chat.domain.repository.ChatRoomRepository;
-import com.ddang.ddang.chat.domain.repository.ReadMessageLogRepository;
 import com.ddang.ddang.image.domain.ProfileImage;
 import com.ddang.ddang.user.domain.Reliability;
 import com.ddang.ddang.user.domain.User;
@@ -22,6 +21,10 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.BASE_URL;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.USER_ID;
+
 @SuppressWarnings("NonAsciiCharacters")
 public class ChatWebSocketHandleTextMessageProviderTestFixture {
 
@@ -46,6 +49,7 @@ public class ChatWebSocketHandleTextMessageProviderTestFixture {
 
     protected Map<String, Object> 발신자_세션_attribute_정보;
     protected Map<String, Object> 수신자_세션_attribute_정보;
+    protected Map<String, Object> 연결이_끊긴_세션_attribute_정보;
     protected Map<String, String> 메시지_전송_데이터;
 
     protected CreateReadMessageLogEvent 메시지_로그_생성_이벤트;
@@ -86,8 +90,21 @@ void setUpFixture() {
 
         chatRoomRepository.save(채팅방);
 
-        발신자_세션_attribute_정보 = new HashMap<>(Map.of("userId", 발신자.getId(), "baseUrl", "/images"));
-        수신자_세션_attribute_정보 = new HashMap<>(Map.of("userId", 수신자.getId(), "baseUrl", "/images"));
+        발신자_세션_attribute_정보 = new HashMap<>(Map.of(
+                USER_ID.getName(), 발신자.getId(),
+                BASE_URL.getName(), "/images",
+                CONNECTED.getName(), true
+        ));
+        수신자_세션_attribute_정보 = new HashMap<>(Map.of(
+                USER_ID.getName(), 수신자.getId(),
+                BASE_URL.getName(), "/images",
+                CONNECTED.getName(), true
+        ));
+        연결이_끊긴_세션_attribute_정보 = new HashMap<>(Map.of(
+                USER_ID.getName(), 수신자.getId(),
+                BASE_URL.getName(), "/images",
+                CONNECTED.getName(), false
+        ));
         메시지_전송_데이터 = Map.of(
                 "chatRoomId", String.valueOf(채팅방.getId()),
                 "receiverId", String.valueOf(수신자.getId()),

backend/ddang/src/test/java/com/ddang/ddang/notification/application/fixture/NotificationEventListenerFixture.java

@@ -34,6 +34,10 @@
 import java.util.List;
 import java.util.Map;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.BASE_URL;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.USER_ID;
+
 @SuppressWarnings("NonAsciiCharacters")
 public class NotificationEventListenerFixture {
 
@@ -117,8 +121,9 @@ void setUpFixture() {
         bidRepository.save(bid);
 
         세션_attribute_정보 = new HashMap<>(Map.of(
-                "userId", 발신자_겸_판매자.getId(),
-                "baseUrl", 이미지_절대_경로
+                USER_ID.getName(), 발신자_겸_판매자.getId(),
+                BASE_URL.getName(), 이미지_절대_경로,
+                CONNECTED.getName(), true
         ));
         메시지_전송_데이터 = Map.of(
                 "chatRoomId", String.valueOf(채팅방.getId()),

backend/ddang/src/test/java/com/ddang/ddang/websocket/handler/WebSocketHandlerTest.java

@@ -12,11 +12,14 @@
 import org.mockito.Mock;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.web.socket.PongMessage;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 
 import java.util.List;
 
+import static com.ddang.ddang.websocket.handler.dto.WebSocketAttributeKey.CONNECTED;
+import static org.assertj.core.api.Assertions.*;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyMap;
 import static org.mockito.BDDMockito.given;
@@ -69,4 +72,16 @@ class WebSocketHandlerTest extends WebSocketHandlerTestFixture {
         // then
         verify(provider, times(1)).remove(any(WebSocketSession.class));
     }
+
+    @Test
+    void pong_메시지_수신시_연결_상태를_참으로_변환한다() {
+        // given
+        given(session.getAttributes()).willReturn(세션_attribute_정보);
+
+        // when
+        webSocketHandler.handlePongMessage(session, new PongMessage());
+
+        // then
+        assertThat((boolean) 세션_attribute_정보.get(CONNECTED.getName())).isTrue();
+    }
 }