我发现用npm request包(https://www.npmjs.com/package/request)非常容易做到这一点。

然后我根据这个帖子http://blog.javascripting.com/2015/01/17/dont-hassle-with-cors/给出了我的解决方案

'use strict'

const express = require('express');
const request = require('request');

let proxyConfig = {
    url : {
        base: 'http://servertoreach.com?id=',
    }
}

/* setting up and configuring node express server for the application */
let server = express();
server.set('port', 3000);


/* methods forwarded to the servertoreach proxy  */
server.use('/somethingElse', function(req, res)
{
    let url = proxyConfig.url.base + req.query.id;
    req.pipe(request(url)).pipe(res);
});


/* start the server */
server.listen(server.get('port'), function() {
    console.log('express server with a proxy listening on port ' + server.get('port'));
});

我在我的server.js文件中使用了下面的方法。这里的关键部分是从请求头中获取起源，然后在服务器响应中允许它，此时我们可以设置将返回的头，包括如果找到匹配则允许的起源。

    **const origin = req.headers.origin;**

      let decoder = new StringDecoder('utf-8');
      let buffer = '';
      req.on('data', function (data) {
        buffer += decoder.write(data);
      });
      req.on('end', function () {
        buffer += decoder.end();

        let chosenHandler = typeof (server.router[trimmedPath]) !== 'undefined' ? server.router[trimmedPath] : handlers.notFound;

const data = { ....data object vars}

// should be wrapped in try catch block
      chosenHandler(data, function (statusCode, payload, contentType) {
        server.processHandlerResponse(res, method, trimmedPath, statusCode, payload, contentType, **origin**);


server.processHandlerResponse = function (res, method, trimmedPath, statusCode, payload, contentType, origin) {
  contentType = typeof (contentType) == 'string' ? contentType : 'json';

  statusCode = typeof (statusCode) == 'number' ? statusCode : 200;

  let payloadString = '';
  if (contentType == 'json') {
    res.setHeader('Content-Type', 'application/json');

    const allowedOrigins = ['https://www.domain1.com', 'https://someotherdomain','https://yetanotherdomain',
    ...// as many as you need
  ];
    **if (allowedOrigins.indexOf(origin) > -1) {
        res.setHeader('Access-Control-Allow-Origin', origin);
    }**
    payload = typeof (payload) == 'object' ? payload : {};
    payloadString = JSON.stringify(payload);
  }

... //  if (other content type) ...rinse and repeat..

尝试将控制权传递给下一个匹配的路由。如果Express首先匹配app.get路由，那么它不会继续到options路由，除非你这样做(注意使用next):

app.get('somethingelse', function(req, res, next) {
    //..set headers etc.

    next();
});

在组织CORS的东西方面，我把它放在一个对我来说很有效的中间件中:

//CORS middleware
var allowCrossDomain = function(req, res, next) {
    res.header('Access-Control-Allow-Origin', 'example.com');
    res.header('Access-Control-Allow-Methods', 'GET,PUT,POST,DELETE');
    res.header('Access-Control-Allow-Headers', 'Content-Type');

    next();
}

//...
app.configure(function() {
    app.use(express.bodyParser());
    app.use(express.cookieParser());
    app.use(express.session({ secret: 'cool beans' }));
    app.use(express.methodOverride());
    app.use(allowCrossDomain);
    app.use(app.router);
    app.use(express.static(__dirname + '/public'));
});

如果你想让它特定于控制器，你可以使用:

res.setHeader("X-Frame-Options", "ALLOWALL");
res.setHeader("Access-Control-Allow-Origin", "*");
res.setHeader("Access-Control-Allow-Methods", "POST, GET");
res.setHeader("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

请注意，这也将允许iframes。

下面的代码将工作，但首先安装cors通过:

NPM安装——保存cors

然后:

module.exports = function(app) { 
var express = require("express");
var cors = require('cors');
var router = express.Router();
app.use(cors());

app.post("/movies",cors(), function(req, res) { 
res.send("test");
});

最简单的答案是使用cors包。

const cors = require('cors');

const app = require('express')();
app.use(cors());

这将使CORS全面启用。如果你想学习如何在没有外部模块的情况下启用CORS，你真正需要的只是一些Express中间件，它可以设置“Access-Control-Allow-Origin”标头。这是允许从浏览器到服务器的交叉请求域所需的最小值。

app.options('*', (req, res) => {
  res.set('Access-Control-Allow-Origin', '*');
  res.send('ok');
});

app.use((req, res) => {
  res.set('Access-Control-Allow-Origin', '*');
});