Question

我正在尝试在node.js中实现websocket服务器而不使用任何框架。从客户端发送消息到服务器工作正常。但现在我尝试从客户端向服务器发送文本文件。我可以在终端中使用console.log查看服务器端的内容。但是：

如何获取文件信息？（姓名，创建/编辑日期等？）
如何保存文件？

客户代码：

(function () {
    'use strict';
    var output, ws;

    //Display logging information in the document
    function log(s) {
        var p = document.createElement("p");
        p.style.wordWrap = "break-word";
        p.textContent = s;
        output.appendChild(p);

        //Also log information on the javascript console
        window.console.log(s);
    }

    //Send a message on the Websocket
    function sendMessage(msg) {
        console.log(ws.binaryType);
        ws.send(msg);
        console.log("Message sent");
    }

    //Initialize WebSocket connection and event handlers
    function setup() {
        output = document.getElementById("output");
        ws = new window.WebSocket("ws://localhost:9999/");

        //Listen for the connection open event then call the sendMessage function
        ws.onopen = function () {
            console.log("Connected");
            document.getElementById('fl').onchange = function() {
                sendMessage(document.querySelector('input[type="file"]').files[0]);
            };
            sendMessage("Hello Galileo!");
        }

        //Listen for the close connection event
        ws.onclose = function (e) {
            if(this.readyState == 2){
                console.log('Connection is closing (Closing Handshake).')
            }
            else if(this.readyState == 3){
                console.log('Connection closed. Has been closed or could not be opened.')
            }
            else{
                console.log('Unhandled ReadyState: ',this.readyState);
            }
            console.log("Disconnected: " + 
                       ' reason:' + e.reason + 
                       ' was clean:' + e.wasClean + 
                       ' code:' + e.code);
        }

        //Listen for connection errors
        ws.onerror = function (e) {
            console.log("Error: " + e);
        }

        //Listen for new messages arriving at the client
        ws.onmessage = function (e) {
            console.log("Message received: " + e.data);
            //Close the socket once one message has arrived
            ws.close();
        }

    }
    //Start running the example
    setup();

})();

HTML代码

<!DOCTYPE html>
<html>
<head>
<title>Websocket Echo Client</title>
<meta charset="utf-8"/>
</head>

<body>
<h2>Websocket Echo Client</h2>
<div id="output"></div>
<input type="file" id="fl"/>
<script src="websocket.js"></script>

</body>

</html>

服务器代码

switch (opcode) {
        case opcodes.TEXT:
          this.payload = payload.toString("utf8");
          winston.log('info','Text:\r\n', this.payload);
          break;
        case opcodes.BINARY:
          console.log('info','File:\r\n', payload.toString("utf8"));

Answer 1

据我所知，您在服务器端接收的有效负载不包含有关该文件的元数据。我认为File对象被视为普通Blob，其中包含一些额外的元数据，而ws.send仅将其视为Blob（it has no special handling for File）。

可以使用

访问元数据

document.querySelector('input[type="file"]').files[0].name
document.querySelector('input[type="file"]').files[0].size
document.querySelector('input[type="file"]').files[0].type

然后单独发送。

如何从websocket连接保存来自客户端的传入文本文件

1 个答案: