WebSocket 连接问题：多个账户订阅余额和持仓频道，为何只有最后一个账户建立连接？

The reason only the last account establishes a connection is because the 'WebSocketClient' instance is a static variable. When you call 'WebSocketConfig.loginConnect(webSocketClient, apikey, passphrase, secretkey);' for each account, you are overwriting the previous connection with a new one.

To fix this issue, you can create a new 'WebSocketClient' instance for each account. Here's an updated version of the code:

@Override
public void subscribe(String apikey, String secretkey, String passphrase) {
    log.info('账户余额和持仓频道');
    WebSocketClient webSocketClient = new WebSocketClient(); // Create a new WebSocketClient instance
    WebSocketConfig.loginConnect(webSocketClient, apikey, passphrase, secretkey);
    ArrayList<Map> channelLists = new ArrayList<>();
    Map spotTickerMap = new HashMap();
    spotTickerMap.put('channel', 'balance_and_position');
    channelLists.add(spotTickerMap);
    //调用订阅方法
    WebSocketClient.subscribe(channelLists);
}

By creating a new 'WebSocketClient' instance for each account, you can establish a separate connection for each account.