实现了客户端、前置端、服务器之间的三重消息传递功能，即由客户端发送消息给前置端，前置端处理后发给服务器，再依次将消息返回客户端-To achieve the client, the front-end server messaging capabilities between the triple, that is, from the client sends a message to the front-end, front-end processing to the server, then