handle multiple websocket sessions in backend

src/main/java/com/kaluwa/enterprises/babycarebackendservice/config/WebSocketClient.java

@@ -4,69 +4,65 @@ import com.fasterxml.jackson.databind.ObjectMapper;
 import com.kaluwa.enterprises.babycarebackendservice.dto.ActivityLogDto;
 import com.kaluwa.enterprises.babycarebackendservice.service.ActivityLogService;
 import com.kaluwa.enterprises.babycarebackendservice.socketHandlers.EmotionPrediction;
-import org.springframework.beans.factory.annotation.Autowired;
-import org.springframework.scheduling.annotation.Scheduled;
-import org.springframework.stereotype.Component;
-import org.springframework.web.socket.BinaryMessage;
+import lombok.Setter;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.web.socket.TextMessage;
 import org.springframework.web.socket.WebSocketSession;
 import org.springframework.web.socket.client.standard.StandardWebSocketClient;
 import org.springframework.web.socket.handler.TextWebSocketHandler;
 
-import java.util.concurrent.Executors;
-import java.util.concurrent.ScheduledExecutorService;
-import java.util.concurrent.TimeUnit;
+import java.io.IOException;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.atomic.AtomicReference;
 
-import static com.kaluwa.enterprises.babycarebackendservice.config.WebSocketConfig.VideoFrameHandler.sendTextMessageToClient;
 import static com.kaluwa.enterprises.babycarebackendservice.constants.Configs.WEBSOCKET_URL;
 import static com.kaluwa.enterprises.babycarebackendservice.constants.LogTypes.EMOTION;
 
+@Slf4j
 public class WebSocketClient {
 
-    private WebSocketSession session;
-    private static final ScheduledExecutorService scheduler = Executors.newSingleThreadScheduledExecutor();
+    private ConcurrentHashMap<String, WebSocketSession> activeSessions = new ConcurrentHashMap<>();
     private ActivityLogService activityLogService;
+    // Method to set the VideoFrameHandler reference
+    @Setter
+    private WebSocketConfig.VideoFrameHandler videoFrameHandler; // Reference to VideoFrameHandler
 
-     public WebSocketClient(ActivityLogService activityLogService) {
+    public WebSocketClient(ActivityLogService activityLogService) {
         this.activityLogService = activityLogService;
-        connectToWebSocket();
     }
 
-    private void connectToWebSocket() {
+    public void connectToWebSocket(String deviceId) {
         try {
-            this.session = new StandardWebSocketClient()
+            WEBSOCKET_URL = WEBSOCKET_URL.replace("{device_id}", deviceId);
+            WebSocketSession session = new StandardWebSocketClient()
                     .doHandshake(new MyWebSocketHandler(this), WEBSOCKET_URL)
                     .get();
-            System.out.println("Connected to WebSocket!");
+            activeSessions.put(deviceId, session); // Store the session
+            log.info("Connected to WebSocket for device: {}", deviceId);
         } catch (Exception e) {
-            System.out.println("Failed to connect to WebSocket, scheduling reconnection...");
-            scheduleReconnection();
+            log.error("Failed to connect to WebSocket for device: {}", deviceId);
+//            e.printStackTrace();
         }
     }
 
-    public void sendBytesToWebSocket(byte[] bytes) {
-        try {
-            session.sendMessage(new BinaryMessage(bytes));
-        } catch (Exception e) {
-            e.printStackTrace();
-        }
-    }
-
-    private void scheduleReconnection() {
-        scheduler.schedule(this::connectToWebSocket, 2, TimeUnit.MINUTES);
-    }
-
-    @Scheduled(fixedDelay = 60000) // Check every 1 minutes
-    private void checkConnection() {
-        if (session == null || !session.isOpen()) {
-            System.out.println("WebSocket connection is closed. Reconnecting...");
-            connectToWebSocket();
+    public void disconnectWebSocket(String deviceId) {
+        WebSocketSession session = activeSessions.remove(deviceId); // Remove session from the map
+        if (session != null && session.isOpen()) {
+            try {
+                session.close(); // Gracefully close the session
+                log.info("WebSocket connection closed successfully for device: {}", deviceId);
+            } catch (IOException e) {
+                log.error("Error while closing WebSocket session for device: {}, Error: {}", deviceId, e.getMessage());
+            }
+        } else {
+            log.error("No active WebSocket connection to close for device: {}", deviceId);
         }
     }
 
     static ObjectMapper objectMapper = new ObjectMapper();
     public static EmotionPrediction[] predictions;
 
+    @Slf4j
     static class MyWebSocketHandler extends TextWebSocketHandler {
 
         private final WebSocketClient webSocketClient;
@@ -77,6 +73,13 @@ public class WebSocketClient {
 
         @Override
         protected void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
+            String deviceId = null;
+            for (String key : webSocketClient.activeSessions.keySet()) {
+                if (webSocketClient.activeSessions.get(key).getId().equals(session.getId())) {
+                    deviceId = key;
+                    break;
+                }
+            }
             // This method will be called when the server sends a text message
             // Deserialize JSON array of objects into an array of Java objects
             predictions = objectMapper.readValue(message.getPayload(), EmotionPrediction[].class);
@@ -86,22 +89,28 @@ public class WebSocketClient {
                 System.out.println("Last emotion prediction: " + lastPrediction);
 
                 // Save the last prediction to the database
-                if (lastPrediction.getEmotion() != null && !lastPrediction.getEmotion().isEmpty()) {
+                if (lastPrediction.getEmotion() != null && !lastPrediction.getEmotion().isEmpty() && !lastPrediction.getError()) {
                     ActivityLogDto activityLogDto = new ActivityLogDto();
                     activityLogDto.setActivityLogType(EMOTION);
                     activityLogDto.setActivityLogDescription(lastPrediction.getEmotion());
                     webSocketClient.activityLogService.saveActivityLog(activityLogDto);
                 }
 
-                // Send the last prediction to the client
-                sendTextMessageToClient(lastPrediction);
+                // Send the last prediction to the client using VideoFrameHandler
+                if (webSocketClient.videoFrameHandler != null && deviceId != null) {
+                    webSocketClient.videoFrameHandler.sendTextMessageToClient(deviceId, lastPrediction);
+                }
             }
         }
 
-         @Override
+        private String getDeviceIdFromSession(WebSocketSession session) {
+            String uri = session.getUri().toString();
+            return uri.substring(uri.lastIndexOf('/') + 1); // Extract device_id from the URI path
+        }
+
+        @Override
         public void afterConnectionClosed(WebSocketSession session, org.springframework.web.socket.CloseStatus status) {
-            System.out.println("WebSocket connection closed. Status: " + status);
-            webSocketClient.scheduleReconnection();
+            log.info("WebSocket connection closed. Status: {}", status);
         }
     }
 }

src/main/java/com/kaluwa/enterprises/babycarebackendservice/config/WebSocketConfig.java

@@ -24,6 +24,9 @@ import org.springframework.web.socket.handler.BinaryWebSocketHandler;
 import springfox.documentation.spring.web.json.Json;
 
 import java.io.IOException;
+import java.util.concurrent.ConcurrentHashMap;
+
+import static com.kaluwa.enterprises.babycarebackendservice.constants.Configs.SERVER_WS_PATH_TO_ANDROID;
 
 @Configuration
 @Slf4j
@@ -37,7 +40,9 @@ public class WebSocketConfig implements WebSocketConfigurer {
 
     @Override
     public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
-        registry.addHandler(new VideoFrameHandler(), "/emotional/video-process").setAllowedOrigins("*");
+        VideoFrameHandler videoFrameHandler = new VideoFrameHandler(customWebSocketClient());
+        customWebSocketClient().setVideoFrameHandler(videoFrameHandler);
+        registry.addHandler(videoFrameHandler, SERVER_WS_PATH_TO_ANDROID);
     }
 
     @Bean
@@ -48,12 +53,20 @@ public class WebSocketConfig implements WebSocketConfigurer {
 
     @Component
     class VideoFrameHandler extends BinaryWebSocketHandler {
-        private static WebSocketSession currentSession;
+        private ConcurrentHashMap<String, WebSocketSession> activeSessions = new ConcurrentHashMap<>();
+        private final WebSocketClient webSocketClient;
+
+        @Autowired
+        public VideoFrameHandler(WebSocketClient webSocketClient) {
+            this.webSocketClient = webSocketClient;
+        }
 
         @Override
         public void afterConnectionEstablished(WebSocketSession session) throws Exception {
-            currentSession = session; // Store the current session
-            log.info("Connection established with client: {}", session);
+            String deviceId = getDeviceIdFromSession(session);
+            activeSessions.put(deviceId, session); // Store the session in the map
+            webSocketClient.connectToWebSocket(deviceId);
+            log.info("Connection established with client for device: {}", deviceId);
             super.afterConnectionEstablished(session);
         }
 
@@ -63,22 +76,29 @@ public class WebSocketConfig implements WebSocketConfigurer {
             // Process the binary data as needed
 
             // Send binary data back to the client
-            sendBinaryMessageToClient(binaryData);
+            sendBinaryMessageToClient(session, binaryData);
 
             // Optionally, send a text message
             EmotionPrediction emotionPrediction = new EmotionPrediction(); // Empty object
-            sendTextMessageToClient(emotionPrediction);
+
+            String deviceId = getDeviceIdFromSession(session);
+            sendTextMessageToClient(deviceId, emotionPrediction);
         }
 
         @Override
         public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
-            if (currentSession == session) {
-                currentSession = null; // Reset session variable
-            }
+            String deviceId = getDeviceIdFromSession(session);
+            activeSessions.remove(deviceId); // Remove session from the map
+            webSocketClient.disconnectWebSocket(deviceId);
             log.info("Connection closed with client: {}", session);
             super.afterConnectionClosed(session, status);
         }
 
+        private String getDeviceIdFromSession(WebSocketSession session) {
+            String uri = session.getUri().toString();
+            return uri.substring(uri.lastIndexOf('/') + 1); // Extract device_id from the URI path
+        }
+
         @Override
         protected void handleTextMessage(WebSocketSession session, TextMessage message) {
             super.handleTextMessage(session, message);
@@ -90,28 +110,29 @@ public class WebSocketConfig implements WebSocketConfigurer {
         }
 
         // Method to send a binary message back to the client
-        public void sendBinaryMessageToClient(byte[] bytes) {
+        public void sendBinaryMessageToClient(WebSocketSession session, byte[] bytes) {
             try {
-                if (currentSession != null && currentSession.isOpen()) {
-                    currentSession.sendMessage(new BinaryMessage(bytes));
-                    System.out.println("Sent binary message to client: " + bytes.length);
+                if (session.isOpen()) {
+                    session.sendMessage(new BinaryMessage(bytes));
+                    log.info("Sent binary message to client: {}", bytes.length);
                 }
             } catch (IOException e) {
-                e.printStackTrace();
+                log.error("Error sending binary message: {}", e.getMessage());
             }
         }
 
         // Method to send a text message back to the client
-        public static void sendTextMessageToClient(EmotionPrediction emotionPrediction) {
+        public void sendTextMessageToClient(String deviceId, EmotionPrediction emotionPrediction) {
             try {
-                if (currentSession != null && currentSession.isOpen()) {
+                WebSocketSession session = activeSessions.get(deviceId);
+                if (session.isOpen()) {
                     ObjectMapper objectMapper = new ObjectMapper();
                     String json = objectMapper.writeValueAsString(emotionPrediction);
-                    currentSession.sendMessage(new TextMessage(json));
-                    System.out.println("Sent text message to client: " + json);
+                    session.sendMessage(new TextMessage(json));
+                    log.info("Sent text message to client: {}", json);
                 }
             } catch (IOException e) {
-                e.printStackTrace();
+                log.error("Error sending text message: {}", e.getMessage());
             }
         }
     }

src/main/java/com/kaluwa/enterprises/babycarebackendservice/constants/Configs.java

 package com.kaluwa.enterprises.babycarebackendservice.constants;
 
 public class Configs {
-    public static final String WEBSOCKET_URL = "ws://localhost:8000/ws/emotion";
+    public static String WEBSOCKET_URL = "ws://localhost:8000/ws/emotion/{device_id}";
+    public static final String SERVER_WS_PATH_TO_ANDROID = "/emotional/video-process/{device_id}";
 }

src/main/java/com/kaluwa/enterprises/babycarebackendservice/constants/TableNames.java

@@ -7,5 +7,6 @@ public class TableNames {
     public final static String DOCUMENT_TABLE = "documents";
     public final static String ACTIVITY_LOG_TABLE = "activity_logs";
     public final static String CONTACT_INFO_TABLE = "contact_info";
+    public final static String DEVICES_TABLE = "devices";
 
 }

src/main/java/com/kaluwa/enterprises/babycarebackendservice/dao/BabyDao.java

@@ -6,4 +6,7 @@ import org.springframework.stereotype.Repository;
 
 @Repository
 public interface BabyDao extends JpaRepository<Baby, Long> {
+    boolean existsByDeviceUidAndBabyIdNot(String deviceUid, Long babyId);
+
+    boolean existsByDeviceUid(String deviceUid);
 }

src/main/java/com/kaluwa/enterprises/babycarebackendservice/dao/DevicesDao.java

+package com.kaluwa.enterprises.babycarebackendservice.dao;
+
+import com.kaluwa.enterprises.babycarebackendservice.model.Devices;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+public interface DevicesDao extends JpaRepository<Devices, Long> {
+  boolean existsByDeviceUid(String deviceUid);
+}
\ No newline at end of file

src/main/java/com/kaluwa/enterprises/babycarebackendservice/dto/BabyDto.java

@@ -26,6 +26,7 @@ public class BabyDto {
     @NotNull(message = "Baby's gender is required")
     @NotEmpty(message = "Baby's gender is required")
     private String sex;
+    private String deviceUid;
     private String status = STATUS_NEW;
     private Boolean isActive;
     private Float weight;

src/main/java/com/kaluwa/enterprises/babycarebackendservice/model/Baby.java

@@ -22,6 +22,7 @@ public class Baby {
     private String lastName;
     private LocalDate dob;
     private String sex;
+    private String deviceUid;
     private String status;
     private Boolean isActive;
     private Float weight;

src/main/java/com/kaluwa/enterprises/babycarebackendservice/model/Devices.java

+package com.kaluwa.enterprises.babycarebackendservice.model;
+
+import jakarta.persistence.*;
+import lombok.AllArgsConstructor;
+import lombok.Data;
+import lombok.NoArgsConstructor;
+
+import static com.kaluwa.enterprises.babycarebackendservice.constants.TableNames.DEVICES_TABLE;
+
+@Data
+@AllArgsConstructor
+@NoArgsConstructor
+@Entity
+@Table(name = DEVICES_TABLE)
+public class Devices {
+
+    @Id
+    @GeneratedValue(strategy= GenerationType.AUTO)
+    private Long deviceId;
+    private String deviceUid;
+
+}

src/main/java/com/kaluwa/enterprises/babycarebackendservice/service/impl/BabyServiceImpl.java

 package com.kaluwa.enterprises.babycarebackendservice.service.impl;
 
 import com.kaluwa.enterprises.babycarebackendservice.dao.BabyDao;
+import com.kaluwa.enterprises.babycarebackendservice.dao.DevicesDao;
 import com.kaluwa.enterprises.babycarebackendservice.dao.DocumentDao;
 import com.kaluwa.enterprises.babycarebackendservice.dto.BabyDto;
 import com.kaluwa.enterprises.babycarebackendservice.dto.ResponseDto;
@@ -32,12 +33,14 @@ public class BabyServiceImpl implements BabyService {
     private final BabyMapper babyMapper;
     private final DocumentDao documentDao;
     private final DocumentService documentService;
+    private final DevicesDao devicesDao;
 
-    public BabyServiceImpl(BabyDao babyDao, BabyMapper babyMapper, DocumentDao documentDao, DocumentService documentService) {
+    public BabyServiceImpl(BabyDao babyDao, BabyMapper babyMapper, DocumentDao documentDao, DocumentService documentService, DevicesDao devicesDao) {
         this.babyDao = babyDao;
         this.babyMapper = babyMapper;
         this.documentDao = documentDao;
         this.documentService = documentService;
+        this.devicesDao = devicesDao;
     }
 
     @Override
@@ -45,6 +48,26 @@ public class BabyServiceImpl implements BabyService {
         log.info("Inside baby service createBaby method");
         try {
             babyDto.setUniqKey(uniqKeyGenerator());
+            if (!babyDto.getDeviceUid().isEmpty() && !devicesDao.existsByDeviceUid(babyDto.getDeviceUid())) {
+                throw new BadRequestAlertException("Device is not registered in the system by uid " + babyDto.getDeviceUid(), "baby", "baby.error");
+            }
+            if (!babyDto.getDeviceUid().isEmpty() && devicesDao.existsByDeviceUid(babyDto.getDeviceUid())) {
+                if (babyDao.existsByDeviceUid(babyDto.getDeviceUid())) {
+                    throw new BadRequestAlertException("Device is already assigned to another baby", "baby", "baby.error");
+                }
+            }
+            if (babyDto.getFirstName().isEmpty()) {
+                throw new BadRequestAlertException("Baby's first name is required", "baby", "baby.error");
+            }
+            if (babyDto.getDob() == null) {
+                throw new BadRequestAlertException("Baby's date of birth is required", "baby", "baby.error");
+            }
+            if (babyDto.getSex().isEmpty()) {
+                throw new BadRequestAlertException("Baby's gender is required", "baby", "baby.error");
+            }
+            if (babyDto.getUserId() == null) {
+                throw new BadRequestAlertException("User id is required", "baby", "baby.error");
+            }
             return babyMapper.toDto(babyDao.save(babyMapper.toEntity(babyDto)));
         } catch (Exception e) {
             e.printStackTrace();
@@ -98,13 +121,34 @@ public class BabyServiceImpl implements BabyService {
             Optional<Baby> babyOp = babyDao.findById(babyId);
             if (babyDto.getBabyId() == null) {
                 throw new BadRequestAlertException("Baby id is required", "baby", "baby.error");
-            } else if (!babyId.equals(babyDto.getBabyId())) {
+            }
+            if (!babyId.equals(babyDto.getBabyId())) {
                 throw new BadRequestAlertException("Baby id mismatch", "baby", "baby.error");
-            } else if (babyOp.isEmpty()) {
+            }
+            if (babyOp.isEmpty()) {
                 throw new BadRequestAlertException("Baby not found", "baby", "baby.error");
-            } else {
-                return babyMapper.toDto(babyDao.save(babyMapper.toEntity(babyDto)));
             }
+            if (!babyDto.getDeviceUid().isEmpty() && !devicesDao.existsByDeviceUid(babyDto.getDeviceUid())) {
+                throw new BadRequestAlertException("Device is not registered in the system by uid " + babyDto.getDeviceUid(), "baby", "baby.error");
+            }
+            if (!babyDto.getDeviceUid().isEmpty() && devicesDao.existsByDeviceUid(babyDto.getDeviceUid())) {
+                if (babyDao.existsByDeviceUidAndBabyIdNot(babyDto.getDeviceUid(), babyId)) {
+                    throw new BadRequestAlertException("Device is already assigned to another baby", "baby", "baby.error");
+                }
+            }
+            if (babyDto.getFirstName().isEmpty()) {
+                throw new BadRequestAlertException("Baby's first name is required", "baby", "baby.error");
+            }
+            if (babyDto.getDob() == null) {
+                throw new BadRequestAlertException("Baby's date of birth is required", "baby", "baby.error");
+            }
+            if (babyDto.getSex().isEmpty()) {
+                throw new BadRequestAlertException("Baby's gender is required", "baby", "baby.error");
+            }
+            if (babyDto.getUserId() == null) {
+                throw new BadRequestAlertException("User id is required", "baby", "baby.error");
+            }
+            return babyMapper.toDto(babyDao.save(babyMapper.toEntity(babyDto)));
         } catch (Exception e) {
             e.printStackTrace();
             throw new BadRequestAlertException(e.getMessage(), "baby", "baby.error");

src/main/java/com/kaluwa/enterprises/babycarebackendservice/socketHandlers/EmotionPrediction.java

@@ -10,4 +10,5 @@ import lombok.NoArgsConstructor;
 public class EmotionPrediction {
     private String emotion;
     private BoundingBox bounding_box;
+    private Boolean error;
 }
\ No newline at end of file