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결론 전달되지 않습니다일부 서버 생성 된 이벤트는 WebSocket을 통해 생산 클라이언트에
일부 서버 생성 된 이벤트가 WebSocket을 통해 생산 클라이언트에 전달되지 않습니다를. 그러나 websocket 연결은 정상적으로 작동합니다.
사례 연구 :
내가 구글 크롬을 열고 우리의 서버에 연결합니다. devtools를 엽니 다. WS 탭에서 연결이 잘된 것을 볼 수 있지만, 서버에서 페이지의 내용을 업데이트해야 할 때 프레임이 수신되지 않습니다. 나는 잠시 동안, 때로는 (때로는) 나는 막대한 양의 지연과 함께 어떤 사건들을 기다린다. 그러나 예상대로 로컬로 작동합니다.
질문 :
누구나 볼 유사한 웹 소켓 동작을 가지고 있으며,이 조사를 위해 변수를 제거하는 방법에 대한 제안이있다.
인프라 :
서버 : 리눅스 톰캣
두 처리 서버 : 사용자로부터 2. 트래픽 (서버에 TCP/IP를 통해 통신) 1. 교통을 장치에서
사용자와 장치는 다 대다 관계입니다. 사용자가 연결된 장치가없는 서버에 연결되면 이 서버는 다른 서버를보고 정보 교환을 처리합니다.
서버 앞에 방화벽이 있습니다.
코드 :
https://github.com/kino6052/websockets-issue
WebSocketServerEndpoint.java
@ServerEndpoint("/actions")
public class WebSocketServerEndpoint {
static private final org.slf4j.Logger logger = LoggerFactory.getLogger(WebSocketServerEndpoint.class);
@OnOpen
public void open(Session session) {
WebSocketSessionHandler.addSession(session);
}
@OnClose
public void close(Session session) {
WebSocketSessionHandler.removeSession(session);
}
@OnError
public void onError(Throwable error) {
//Logger.getLogger(WebSocketServerEndpoint.class.getName()).log(Level.SEVERE, null, error);
}
@OnMessage
public void handleMessage(String message, Session session) {
try (JsonReader reader = Json.createReader(new StringReader(message))) {
JsonObject jsonMessage = reader.readObject();
Long userId = null;
Long tenantId = null;
switch (WebSocketActions.valueOf(jsonMessage.getString("action"))){
case SaveUserId:
userId = getUserId(jsonMessage);
tenantId = getTenantId(jsonMessage);
Long userIdKey = WebSocketSessionHandler.saveUserId(userId, session);
Long tenantUserKey = WebSocketSessionHandler.saveTenantUser(tenantId, userId);
WebSocketSessionHandler.updateUserSessionKeys(session, tenantUserKey, userIdKey); // Needed for Making Weak Maps Keep Their Keys if Session is Currently Active
}
} catch (Exception e) {
logger.error(e.toString());
}
}
private Long getUserId(JsonObject jsonMessage) {
Long userId = null;
try {
userId = Long.parseLong(((Integer) jsonMessage.getInt("userId")).toString());
return userId;
} catch (Exception e) {
logger.error(e.getMessage());
return userId;
}
}
private Long getTenantId(JsonObject jsonMessage) {
Long tenantId = null;
try {
tenantId = Long.parseLong(((Integer) jsonMessage.getInt("tenantId")).toString());
return tenantId;
} catch (Exception e) {
logger.error(e.getMessage());
return tenantId;
}
}
}
WebSocketService.java
@Singleton
public class WebSocketService {
private static final Logger logger = LoggerFactory.getLogger(WebSocketService.class);
public enum WebSocketEvents{
OnConnection,
OnActivity,
OnAccesspointStatus,
OnClosedStatus,
OnConnectedStatus,
OnAlert,
OnSessionExpired
}
public enum WebSocketActions{
SaveUserId
}
@WebPost("/lookupWebSocketSessions")
public WebResponse lookupWebSocketSessions(@JsonArrayParam("userIds") List<Integer> userIds, @WebParam("message") String message){
try {
for (Integer userIdInt : userIds) {
Long userId = Long.parseLong(userIdInt.toString());
if (WebSocketSessionHandler.sendToUser(userId, message) == 0) {
} else {
//logger.debug("Couldn't Send to User");
}
}
} catch (ClassCastException e) {
//logger.error(e.getMessage());
return webResponseBuilder.fail(e);
} catch (Exception e) {
//logger.error(e.getMessage());
return webResponseBuilder.fail(e);
}
return webResponseBuilder.success(message);
}
@WebPost("/lookupWebSocketHistorySessions")
public WebResponse lookupWebSocketHistorySessions(@JsonArrayParam("userIds") List<Integer> userIds, @WebParam("message") String message){
try {
for (Integer userIdInt : userIds) {
Long userId = Long.parseLong(userIdInt.toString());
if (WebSocketHistorySessionHandler.sendToUser(userId, message) == 0) {
} else {
//logger.debug("Couldn't Send to User");
}
}
} catch (ClassCastException e) {
//logger.error(e.getMessage());
return webResponseBuilder.fail(e);
} catch (Exception e) {
//logger.error(e.getMessage());
return webResponseBuilder.fail(e);
}
return webResponseBuilder.success(message);
}
// Kick Out a User if Their Session is no Longer Valid
public void sendLogout(User user) {
try {
Long userId = user.getId();
List<Long> userIds = new ArrayList<>();
userIds.add(userId);
JSONObject result = new JSONObject();
result.put("userId", userId);
JSON message = WebSocketSessionHandler.createMessage(WebSocketEvents.OnSessionExpired, result);
lookOnOtherServers(userIds, message);
} catch (Exception e) {
logger.error("Couldn't Logout User");
}
}
// Send History after Processing Data
// Returns "0" if success, "-1" otherwise
public int sendHistory(Activity activity) {
try {
TimezoneService.TimeZoneConfig timeZoneConfig = timezoneService.getTimezoneConfigsByAp(null, activity.getAccesspointId());
JSONObject result = (JSONObject) JSONSerializer.toJSON(activity);
String timezoneId = timezoneService.convertTimezoneConfigToTimezoneId(timeZoneConfig);
result.put("timezoneString", timezoneId);
result.put(
"profileId",
userDao.getUserProfileId(activity.getUserId())
);
JSON message = WebSocketHistorySessionHandler.createMessage(WebSocketEvents.OnActivity, result);
List<Long> userIds = getUsersSubscribedToActivity(activity.getTenantId());
lookOnOtherServersHistory(userIds, message);
return 0;
} catch (Exception e) {
//logger.error("Couldn't Send History");
return -1;
}
}
// SendAlertUpdate after Processing Data
public void sendAlertUpdate(Alert alert) {
try {
List<Long> userIds = getUsersUnderTenantByAccesspointId(alert.getAccesspointId());
JSONObject result = JSONObject.fromObject(alert);
JSON message = WebSocketSessionHandler.createMessage(WebSocketEvents.OnAlert, result);
lookOnOtherServers(userIds, message);
} catch (Exception e) {
//logger.error("Couldn't Send Aleart");
}
}
// Send Connected Status after Processing Data
public void sendConnectedStatus(Long accesspointId, Boolean isConnected) {
try {
List<Long> userIds = getUsersUnderTenantByAccesspointId(accesspointId);
JSONObject result = new JSONObject();
result.put("accesspointId", accesspointId);
result.put("isConnected", isConnected);
JSON message = WebSocketSessionHandler.createMessage(WebSocketEvents.OnConnectedStatus, result);
lookOnOtherServers(userIds, message);
} catch (Exception e) {
//logger.error("Couldn't Send Connected Status");
}
}
public int sendHistory(CredentialActivity activity) {
try {
TimezoneService.TimeZoneConfig timeZoneConfig = timezoneService.getTimezoneConfigsByAp(null, activity.getAccesspointId());
JSONObject result = (JSONObject) JSONSerializer.toJSON(activity);
String timezoneId = timezoneService.convertTimezoneConfigToTimezoneId(timeZoneConfig);
result.put("timezoneString", timezoneId);
result.put(
"profileId",
userDao.getUserProfileId(activity.getUserId())
);
JSON message = WebSocketHistorySessionHandler.createMessage(WebSocketEvents.OnActivity, result);
List<Long> userIds = getUsersUnderTenantByAccesspointId(activity.getAccesspointId());
lookOnOtherServersHistory(userIds, message);
return 0;
} catch (Exception e) {
return -1;
}
}
public Boolean isUserSessionAvailable(Long id) {
return WebSocketSessionHandler.isUserSessionAvailable(id);
}
public void lookOnOtherServers(List<Long> userId, JSON data){
List<String> urls = awsService.getServerURLs();
for (String url : urls) {
postJSONDataToUrl(url, userId, data);
}
}
public void lookOnOtherServersHistory(List<Long> userId, JSON data){
List<String> urls = awsService.getServerURLsHistory();
for (String url : urls) {
postJSONDataToUrl(url, userId, data);
}
}
public int sendClosedStatus(AccesspointStatus accesspointStatus){
try {
JSONObject accesspointStatusJSON = new JSONObject();
accesspointStatusJSON.put("accesspointId", accesspointStatus.getAccesspointId());
accesspointStatusJSON.put("openStatus", accesspointStatus.getOpenStatus());
List<Long> userIds = getUsersUnderTenantByAccesspointId(accesspointStatus.getAccesspointId());
lookOnOtherServers(userIds, accesspointStatusJSON);
return 0;
} catch (Exception e) {
return -1;
}
}
public List<Long> getUsersSubscribedToActivity(Long tenantId) {
List<Long> userList = WebSocketSessionHandler.getUsersForTenant(tenantId);
return userList;
}
private List<Long> getUsersUnderTenantByAccesspointId(Long accesspointId) {
List<Long> userList = new ArrayList<>();
User user = userDao.getBackgroundUserByAccesspoint(accesspointId);
List<Record> recordList = tenantDao.getTenantsByUser(user, user.getId());
for (Record record : recordList) {
Long tenantId = (Long) record.get("id");
userList.addAll(getUsersSubscribedToActivity(tenantId));
}
return userList;
}
public void postJSONDataToUrl(String url, List<Long> userId, JSON data) throws AppException {
List<NameValuePair> parameters;
HttpResponse httpResponse;
HttpClientService.SimpleHttpClient simpleHttpClient = httpClientService.createHttpClient(url);
try {
parameters = httpClientService.convertJSONObjectToNameValuePair(userId, data);
} catch (Exception e) {
throw new AppException("Couldn't Convert Input Parameters");
}
try {
httpResponse = simpleHttpClient.sendHTTPPost(parameters);
} catch (Exception e) {
throw new AppException("Couldn't Get Data from the Server");
}
if (httpResponse == null) {
throw new AppException("Couldn't Send to Another Server");
} else {
//logger.error(httpResponse.getStatusLine().toString());
}
}
}
WebSocketSessionHandler.java
public class WebSocketSessionHandler {
// Apparently required to instantiate the dialogue,
// ideally it would be better to just create session map where sessions are mapped to userId,
// however, userId will be send only after the session is created.
// TODO: Investigate Instantiation of WebSocket Session Further
// WeakHashMap is Used for Automatic Memory Management (So That Removal of Keys That are no Longer Used Can be Automatically Performed)
// NOTE: However, it Requires Certain Precautions to Make Sure Their Keys Don't Expire Unexpectedly, Look for the Commented Code Below
private static final Map<Long, Set<Session>> sessionMap = new WeakHashMap<>();
private static final Map<Long, Set<Long>> tenantUserMap = new WeakHashMap<>();
public WebSocketSessionHandler() {}
public static List<Long> getUsersForTenant(Long tenantId) {
List<Long> userIds = new ArrayList<>();
Set<Long> userIdsSet = tenantUserMap.get(tenantId);
if (userIdsSet != null) {
for (Long userId : userIdsSet){
userIds.add(userId);
}
}
return userIds;
}
public static Boolean isUserSessionAvailable(Long id){
Set<Session> userSessions = sessionMap.get(id);
if (userSessions == null || userSessions.size() == 0) {
return false;
} else {
return true;
}
}
// addSession() should add "session" to "sessions" set
// returns: "0" if success and "-1" otherwise
public static int addSession(Session session) {
int output;
try {
final long ONE_DAY = 86400000;
session.setMaxIdleTimeout(ONE_DAY);
sessions.put(session, new ArrayList<>());
return sendToSession(session, createMessage(WebSocketEvents.OnConnection, "Successfully Connected"));
} catch (Exception e) {
logger.error("Couldn't Add Session");
return -1;
}
}
// removeSession() should remove "session" from "sessions" set
// Scenarios:
// sessions is null?
// returns: "0" if success and "-1" otherwise
public static int removeSession(Session session) {
try {
closeSessionProperly(session);
if (sessions.remove(session) != null) {
return 0;
} else {
return -1;
}
} catch (Exception e) {
logger.error("Couldn't Remove Session");
return -1;
}
}
private static void closeSessionProperly(Session session) {
try {
session.close();
} catch (IOException ex) {
}
}
public static Long getKeyFromMap(Map map, Long key){ // Needed for Weak Maps
Set<Long> keySet = map.keySet();
for (Long keyReference : keySet) {
if (keyReference == key) {
return keyReference;
}
}
return key; // If Not Found Return the Value Passed in
}
// saveUserId() should create an { userId -> session } entry in sessionMap
public static Long saveUserId(Long userId, Session session){
// Test Scenarios:
// Can userId be null or wrong?
// Can session be null or wrong?
try {
userId = getKeyFromMap(sessionMap, userId); // Required for Weak Maps to Work Correctly
Set<Session> sessionsForUser = sessionMap.get(userId);
if (sessionsForUser == null) {
sessionsForUser = new HashSet<>();
}
sessionsForUser.add(session);
sessionMap.put(userId, sessionsForUser);
return userId;
} catch (Exception e) {
logger.error("Couldn't Save User Id");
return null;
}
}
// saveUserId() should create an { userId -> session } entry in sessionMap
public static Long saveTenantUser(Long tenantId, Long userId){
// Test Scenarios:
// Can userId be null or wrong?
// Can session be null or wrong?
try {
tenantId = getKeyFromMap(tenantUserMap, tenantId); // Required for Weak Maps to Work Correctly
Set<Long> users = tenantUserMap.get(tenantId);
if (users == null) {
users = new HashSet<>();
}
users.add(userId);
tenantUserMap.put(tenantId, users);
return tenantId;
} catch (Exception e) {
logger.error("Couldn't Save Tenant User");
return null;
}
}
public static void updateUserSessionKeys(Session session, Long tenantId, Long userId) {
try {
List<Long> userSessionKeys = sessions.get(session);
userSessionKeys.add(0, tenantId);
userSessionKeys.add(1, userId);
} catch (Exception e) {
logger.error("Couldn't Update User Session Keys");
}
}
// removeUserId() should remove an { userId -> session } entry in sessionMap
// returns: "0" if success and "-1" otherwise
public static int removeUserId(Long userId) {
try {
sessionMap.remove(userId);
return 0;
} catch (Exception e) {
return -1;
}
}
// sendAccesspointStatus() should compose JSON message and pass it to sendToUser()
// returns: "0" if success and "-1" otherwise
public static int sendClosedStatus(Long userId, JSONObject accesspointStatus) {
try {
JSONObject accesspointStatusEventMessage = (JSONObject) createMessage(WebSocketEvents.OnClosedStatus, accesspointStatus);
sendToUser(userId, accesspointStatusEventMessage);
return 0;
} catch (Exception e) {
return -1;
}
}
// sendToUser() sends message to session that is mapped to userId
// returns: "0" if success and "-1" otherwise
public static int sendToUser(Long userId, JSON message) {
if (sessionMap.containsKey(userId)) {
Set<Session> sessionsForUser = sessionMap.get(userId);
for (Session session : sessionsForUser) {
if (!session.isOpen()) {
sessions.remove(session);
continue;
}
sendToSession(session, message);
}
return 0;
} else {
return -1;
}
}
// sendToSession() sends string message to session
// returns: "0" if success and "-1" otherwise
private static int sendToSession(Session session, JSON message){
try {
try {
Long tenantId = sessions.get(session).get(0);
((JSONObject) message).put("tenantId", tenantId);
} catch (Exception e) {
logger.error("No tenantId Found");
}
session.getBasicRemote().sendText(message.toString());
return 0;
} catch (IOException e) {
try {
session.close();
} catch (IOException ex) {
}
closeSessionProperly(session);
sessions.remove(session);
return -1;
}
}
// sendToSession() sends string message to session
// returns: "0" if success and "-1" otherwise
private static int sendToSession(Session session, String message){
try {
JSONObject newMessage = JSONObject.fromObject(message);
try {
Long tenantId = sessions.get(session).get(0);
newMessage.put("tenantId", tenantId);
} catch (Exception e) {
logger.error("No tenantId Found");
}
session.getBasicRemote().sendText(newMessage.toString());
return 0;
} catch (IOException e) {
closeSessionProperly(session);
sessions.remove(session);
return -1;
}
}
}
하지 (내 의견에서 복사가.이 솔루션을했다 밝혀졌습니다)하지만'WebSocketSessionHandler' 클래스는 스레드로부터 안전하지 않습니다. 그것은 동기화되지 않은 내부적으로'WeakHashMap'을 사용합니다. 이러한지도에 동시에 액세스하면 예기치 않은 동작이 발생할 수 있으며 이는 사용자가보고있는 효과를 유발할 수도 있고 그렇지 않을 수도 있습니다. – defnull
@defnull 답장을 보내 주셔서 감사합니다. 이 방법으로 문제가 해결되고 업데이트가 제공되는지 확인하겠습니다. –
@defnull, weakhashmap을 잠재적 인 버그로 지적했습니다. 내가 upvote 수 있도록 귀하의 답변을 게시하십시오. –