客户端发送心跳（可以是一个字符串），如果一段时间没有收到心跳报文，服务端就断开连接

关闭是会抛出异常的，捕捉之后进行处理，退出循环

@Override

public void run() {
    Boolean isExit = false;
    while (!isExit) {
        try {
            InputStream is = socket.getInputStream();
            InputStreamReader isr = new InputStreamReader(is);
            BufferedReader br = new BufferedReader(isr);
            String info = null;
            while ((info = br.readLine()) != null) {
                receiveMsg(info);
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            HandleException.addEx(e);
            isExit = true;
        }
    }
    if (isExit)
        SocketManager.connSockets.remove(clientName);
}