서버가 클라이언트에게 Ping/Pong 요청

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

@@ -16,20 +16,27 @@
 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;
 
+@Slf4j
 @Component
 @RequiredArgsConstructor
 public class ChatWebSocketHandleTextMessageProvider implements WebSocketHandleTextMessageProvider {
 
+    private static final String PING_STATUS_KEY = "pingStatus";
     private final WebSocketChatSessions sessions;
     private final ObjectMapper objectMapper;
     private final MessageService messageService;
@@ -136,6 +143,39 @@ 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 pingStatus = (boolean) attributes.get(PING_STATUS_KEY);
+        if (!pingStatus) {
+            sessions.remove(session);
+            return;
+        }
+
+        attributes.put(PING_STATUS_KEY, 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

@@ -29,6 +29,7 @@ public boolean beforeHandshake(
     ) throws Exception {
         attributes.put("userId", findUserId(request));
         attributes.put("baseUrl", ImageRelativeUrl.USER.calculateAbsoluteUrl());
+        attributes.put("pingStatus", true);
 
         return super.beforeHandshake(request, response, wsHandler, attributes);
     }

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

@@ -7,17 +7,20 @@
 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;
 
 @Component
 @RequiredArgsConstructor
 public class WebSocketHandler extends TextWebSocketHandler {
 
     private static final String TYPE_KEY = "type";
+    private static final String PING_STATUS_KEY = "pingStatus";
 
     private final WebSocketHandleTextMessageProviderComposite providerComposite;
     private final ObjectMapper objectMapper;
@@ -43,4 +46,10 @@ public void afterConnectionClosed(final WebSocketSession session, final CloseSta
         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(PING_STATUS_KEY, true);
+    }
 }

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;
@@ -46,6 +45,7 @@ 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 +86,21 @@ 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(
+                "userId", 발신자.getId(),
+                "baseUrl", "/images",
+                "pingStatus", true
+        ));
+        수신자_세션_attribute_정보 = new HashMap<>(Map.of(
+                "userId", 수신자.getId(),
+                "baseUrl", "/images",
+                "pingStatus", true
+        ));
+        연결이_끊긴_세션_attribute_정보 = new HashMap<>(Map.of(
+                "userId", 수신자.getId(),
+                "baseUrl", "/images",
+                "pingStatus", false
+        ));
         메시지_전송_데이터 = Map.of(
                 "chatRoomId", String.valueOf(채팅방.getId()),
                 "receiverId", String.valueOf(수신자.getId()),

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

@@ -12,11 +12,13 @@
 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 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 +71,16 @@ class WebSocketHandlerTest extends WebSocketHandlerTestFixture {
         // then
         verify(provider, times(1)).remove(any(WebSocketSession.class));
     }
+
+    @Test
+    void pong_메시지_수신시_ping_상태를_참으로_변환한다() {
+        // given
+        given(session.getAttributes()).willReturn(세션_attribute_정보);
+
+        // when
+        webSocketHandler.handlePongMessage(session, new PongMessage());
+
+        // then
+        assertThat((boolean) 세션_attribute_정보.get(ping_상태_키)).isTrue();
+    }
 }

backend/ddang/src/test/java/com/ddang/ddang/websocket/handler/fixture/WebSocketHandlerTestFixture.java

@@ -10,10 +10,11 @@
 public class WebSocketHandlerTestFixture {
 
     protected Long 사용자_아이디 = 1L;
+    protected String ping_상태_키 = "pingStatus";
     protected Map<String, Object> 세션_attribute_정보 = new HashMap<>(
             Map.of(
                     "type", TextMessageType.CHATTINGS.name(),
-                    "data", Map.of("userId", 사용자_아이디, "baseUrl", "/images")
+                    "data", Map.of("userId", 사용자_아이디, "baseUrl", "/images", ping_상태_키, false)
             )
     );
     protected TextMessage 전송할_메시지 = new TextMessage("메시지");