nodejs初学示例

解决Node.js上传文件权限问题

最新推荐文章于 2025-09-12 15:58:40 发布

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最新推荐文章于 2025-09-12 15:58:40 发布

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文章标签： python

原文链接：https://my.oschina.net/robinjiang/blog/168737

2019独角兽企业重金招聘Python工程师标准>>>

最近学习nodejs，参考文章：http://www.nodebeginner.org/index-zh-cn.html。

其中在最后一个实例中，按照教程编写代码会出现以下错误：

Error: EXDEV, cross-device link not permitted 'C:\Users\DONGQI~1\AppData\Local\T
emp\726b6c28afd4cc33c2644e203756d4cd'
    at Object.fs.renameSync (fs.js:543:18)
    at F:\nodejsSpace\requestHandlers.js:34:8
    at IncomingForm.<anonymous> (F:\nodejsSpace\node_modules\formidable\lib\inco
ming_form.js:92:9)
    at IncomingForm.EventEmitter.emit (events.js:92:17)
    at IncomingForm._maybeEnd (F:\nodejsSpace\node_modules\formidable\lib\incomi
ng_form.js:533:8)
    at F:\nodejsSpace\node_modules\formidable\lib\incoming_form.js:211:12
    at WriteStream.<anonymous> (F:\nodejsSpace\node_modules\formidable\lib\file.
js:70:5)
    at WriteStream.g (events.js:175:14)
    at WriteStream.EventEmitter.emit (events.js:117:20)
    at finishMaybe (_stream_writable.js:354:12)

查找资料说是windows下没有相关权限导致，只需要在var form = new formidable.IncomingForm();后加一句：form.uploadDir = 'tmp' 改变上传目录的地址就可以了。

以下为示例代码：

1、server.js

var http = require("http");
var url = require("url");

function start(route, handle) {
  function onRequest(request, response) {
    var pathname = url.parse(request.url).pathname;
    console.log("Request for " + pathname + " received.");
    route(handle, pathname, response, request);
  }

  http.createServer(onRequest).listen(8888);
  console.log("Server has started.");
}

exports.start = start;

2、index.js

var server = require("./server");
var router = require("./router");
var requestHandlers = require("./requestHandlers");

var handle = {}
handle["/"] = requestHandlers.start;
handle["/start"] = requestHandlers.start;
handle["/upload"] = requestHandlers.upload;
handle["/show"] = requestHandlers.show;

server.start(router.route, handle);

3、router.js

function route(handle, pathname, response, request) {
  console.log("About to route a request for " + pathname);
  if (typeof handle[pathname] === 'function') {
    handle[pathname](response, request);
  } else {
    console.log("No request handler found for " + pathname);
    response.writeHead(404, {"Content-Type": "text/html"});
    response.write("404 Not found");
    response.end();
  }
}

exports.route = route;

4、requestHandlers.js

var querystring = require("querystring"), fs = require("fs"),
    formidable = require("formidable");

function start(response, postData) {
  console.log("Request handler 'start' was called.");

  var body = '<html>'+
    '<head>'+
    '<meta http-equiv="Content-Type" '+
    'content="text/html; charset=UTF-8" />'+
    '</head>'+
    '<body>'+
    '<form action="/upload" enctype="multipart/form-data" '+
    'method="post">'+
    '<input type="file" name="upload">'+
    '<input type="submit" value="Upload file" />'+
    '</form>'+
    '</body>'+
    '</html>';

    response.writeHead(200, {"Content-Type": "text/html"});
    response.write(body);
    response.end();
}

function upload(response, request) {
  console.log("Request handler 'upload' was called.");

  var form = new formidable.IncomingForm();
  form.uploadDir = 'tmp';
  console.log("about to parse");
  form.parse(request, function(error, fields, files) {
    console.log("parsing done");
    fs.renameSync(files.upload.path, "./tmp/test.png");
    response.writeHead(200, {"Content-Type": "text/html"});
    response.write("received image:<br/>");
    response.write("<img src='/show' />");
    response.end();
  });
}

function show(response, postData) {
  console.log("Request handler 'show' was called.");
  fs.readFile("./tmp/test.png", "binary", function(error, file) {
    if(error) {
      response.writeHead(500, {"Content-Type": "text/plain"});
      response.write(error + "\n");
      response.end();
    } else {
      response.writeHead(200, {"Content-Type": "image/png"});
      response.write(file, "binary");
      response.end();
    }
  });
}

exports.start = start;
exports.upload = upload;
exports.show = show;