public class HumanAgentSocket extends TextWebSocketHandler {
      
        @Value("${human.agents.available}")
        private int availableHumanAgents;
        private List<WebSocketSession> sessions = new ArrayList<>();
        private List<String> sessionIds = new ArrayList<>();
        private HashMap<WebSocketSession,WebSocketSession> socketConnections = new          HashMap<WebSocketSession,WebSocketSession>();
        private int noOfHumanAgents = 1;
        private ObjectMapper objectMapper = new ObjectMapper();
        @Override
        public void afterConnectionEstablished(WebSocketSession session) throws IOException {
           if (noOfHumanAgents<=5){
               System.out.println("Agents "+availableHumanAgents);
               sessions.add(session);
            sessionIds.add(session.getId());
            System.out.println("List "+sessionIds);
            if(sessions.size() == 2){
                socketConnections.put(sessions.get(0),sessions.get(1));
                socketConnections.put(sessions.get(1),sessions.get(0));
                System.out.println("SocketConnections "+socketConnections);
                sessions.clear();
                noOfHumanAgents++;
                System.out.println("Sessios "+sessions.size());
            }
        }else {
            throw  new HumanAgentException("agents are busy");
        }

    }

    @Override
    public void handleTextMessage(WebSocketSession session, TextMessage message) throws Exception {
        WebSocketSession webSocketSession = socketConnections.get(session);
        String payload = message.getPayload();
        JsonNode jsonNode = objectMapper.readTree(payload);
        String content = jsonNode.get("message").asText();
        if (content.equalsIgnoreCase("CLOSE")){
            afterConnectionClosed(session,null);
        }
        if (webSocketSession.isOpen()){
            webSocketSession.sendMessage(message);
        }
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus status) throws Exception {
        WebSocketSession humanAgentSession = socketConnections.get(session);
        if(humanAgentSession!=null){
            sessions.add(humanAgentSession);
        }
        socketConnections.remove(session);
        socketConnections.remove(humanAgentSession);
    }

    public String getWebSocketSession(String sessionId){
        System.out.println("List "+sessionIds);
        String webSocketSession = sessionIds.get(Integer.parseInt(sessionId));
        return webSocketSession;
    }
}

Here I am trying to access the configurable value from application.properties and Even I tried from environment variables also but always it’s value coming as 0 for ‘availableHumanAgents’ variable but the excepted will be the value which I specified or configured in application.properties file.