如何用Express启用cors节点？

Question

总之，我使用了一个类似dicom文件api的查看器，称为基石，为此我连接到dc4chee的WADO服务来获取dicom，dcm4chee运行端口8080，而我在node上的应用程序使用端口3000，所以我试图显示浏览器的dicom。

XMLHttpRequest can not load http: // localhost: 8080 / wado? RequestType = WADO & studyUID = 1.2.840.113704.1.111.5 ... 26513.429 & contentType = application% 2Fdicom & transferSyntax = 1.2.840.10008.1.2. In 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http: // localhost: 3000' is therefore not allowed access.

Var http = require ('http'),
    HttpProxy = require ('http-proxy');

Var proxy = httpProxy.createProxyServer ({target: 'http: // localhost: 8042'}) .listen (8000);

Proxy.on ('proxyRes', function (proxyReq, req, res, options) {
  // add the CORS header to the response
  Res.setHeader ('Access-Control-Allow-Origin', '*');
});

Proxy.on ('error', function (e) {
  // suppress errors
});

在这里也使用npm cors代码

Var express = require ('express')
Var cors = require ('cors')
Var app = express ()
 
App.get ('/ products /: id', cors (), function (req, res, next) {
  Res.json ({msg: 'This is CORS-enabled for a Single Route'))
})
 
App.listen (80, function () {
  Console.log ('CORS-enabled web server listening on port 80')
})

但是我启用了端口3000而不是8080上的cors，我需要在头响应中激活或添加“Access-Control-Allow-Origin”而不是在头请求中激活或添加“Access-Controll-Origin”的模式，

如何在dcm4chee从NodeJS运行的端口8080上添加CORS？

Content-Type:application/dicom
Date:Sat, 01 Apr 2017 01:15:38 GMT
Expires:0
Server:Apache-Coyote/1.1
Transfer-Encoding:chunked
X-Powered-By:Servlet 2.4; JBoss-4.2.3.GA (build: SVNTag=JBoss_4_2_3_GA 
date=200807181439)/JBossWeb-2.0

请求报头

Accept:*/*
Accept-Encoding:gzip, deflate, sdch, br
Accept-Language:es-ES,es;q=0.8,en-US;q=0.6,en;q=0.4
Connection:keep-alive
Host:localhost:8080
Origin:http: //localhost:3000
Referer:http: //localhost:3000/
User-Agent:Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like 
Gecko) Chrome/55.0.2883.87 Safari/537.36

如何在响应头中启用CORS？？

Answer 1

做

npm install cors --save

只需将这些行添加到主文件中请求所在的位置。

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