netty soket 通訊中發消息給特定client id

可以在handler處理函數中，客戶端主動註冊一個id（例如設備imei號），通過下面的類似實現，放入一個HashMap中。

然後就可以實現發消息給特定client id了。

 

    public static synchronized int getClientId(int clientId) {
        Channel channel = mChannels.get("" + clientId);
        if (channel != null) {
            logger.info("getClientId: alreay exist, clientId=" + clientId);
            return clientId;
        } else {
            mClientIdCounter++;
            logger.info("getClientId: getClientId=" + mClientIdCounter);
            return mClientIdCounter;
        }
    }

    public static synchronized void addClient(String clientId, Channel sc) {
        Channel channel = mChannels.get(clientId);
        if (channel != null) {
            logger.info("addClient: alreay in, clientId=" + clientId);
        } else {
            logger.info("addClient: add new, clientId=" + clientId);
            mChannels.put(clientId, sc);
        }
    }

    public static synchronized void removeClient(String clientId) {
        Channel channel = mChannels.get(clientId);
        if (channel != null) {
            mChannels.remove(clientId);
            logger.info("removeClient: removed, clientId=" + clientId);
        } else {
            logger.info("removeClient: not found, clientId=" + clientId);
        }
    }

    private static class LoggingListener implements ChannelFutureListener {
        @Override
        public void operationComplete(ChannelFuture future) {
            logger.info("LoggingListener: sendMsgToClient done");
        }
    }

    public static void sendMsgToClient(String clientId, Object object) {
        Channel channel = mChannels.get(clientId);
        if (channel != null && channel.isActive()) {
            ChannelPromise promise = channel.newPromise();
            promise.addListener(new LoggingListener());
            channel.writeAndFlush(object, promise);
            logger.info("sendMsgToClient: run done");
        }
    }