Question

大家好我正在使用jade生成html并在页面上显示此表单：

      p Upload New Schedule
      #uploadNew
        form(id = "form1", action="/upload", method="post", enctype="multipart/form-data")
          input(type="file", id="control")
          br
          input(type="submit" value="Upload" name="Submit")

当我选择文件并尝试上传时，连接超时。我究竟做错了什么？我正在使用multer中间件来帮助上传：

回到app.js：

var multer = require('multer');
var upload = multer({dest: './uploads'});

...

app.post('/upload', upload.single('Submit'), function(req, res) {
    if (done == true) {
        console.log(req.files);
        res.end("File uploaded");
    }
});

Answer 1

除了gaurav gupta的回答，当使用multer的upload.single()函数作为中间件时，您的文件将位于req.file，而不是req.files。 req.files用于upload.array()或upload.any()。

var multer = require('multer');
var upload = multer({dest: './uploads'});

app.post('/upload', upload.single('control'), function(req, res) {
  console.log(req.file);
  res.send("File uploaded");
});

Answer 2

使用multer上传和检索多个文件（一个二进制文件，一个JSON）的复制粘贴示例...

客户端：

<form action="" method="post" enctype="multipart/form-data"> 
    <input type="file" name="binaryFileToUpload" id="binaryFileToUpload" >
    <input type="file" name="jsonFileToUpload" id="jsonFileToUpload" >
    <input type="button" value="Upload" name="submit" onclick="upload()">
</form>
<script>
upload()
{
    let fileInput = document.getElementById("file");

    var one = fileInput.files[0]; //binary
    var two = new Blob([JSON.stringify(this.someRegularObj, null, 2)], 
    {type : 'application/json'}); //JSON

    var url = "http://localhost:4000/upload"; //your URL here
    var xhr = new XMLHttpRequest();

    xhr.onload = function() {
        alert('File(s) uploaded!');
    };
    xhr.open("POST", url, true);

    if (window.FormData) // Chrome
    {
        var formData = new FormData();
        //must match server's router.post('/receiveFiles', upload.array("upload", ...), ...
        formData.append("upload", one);
        formData.append("upload", two);

        xhr.send(formData);
    }
}
</script>

服务器端（ES6模块/类）：

defineRoutes()
{
    let upload = multer({storage: multer.memoryStorage()});

    let selector = "upload"; //must match client's formData.append() key!
    let numFiles = 2;

    router.post('/receiveFiles', upload.array(selector, numFiles),
        this.tryExtractFilesFromRequest.bind(this)
        );
}

tryExtractFilesFromRequest(req,res,next)
{
    if (req.files)
    {
        let one      = req.files[0];
        console.log(one); //instance of File, has .buffer, a binary representation

        let twoAsJsonString = Buffer.from(req.files[1].buffer, 'binary').toString('utf8');
        let two = JSON.parse(twoAsJsonString);

        res.end();
    }
}

无法上传文件（Express / Node，Multer）

2 个答案: