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nodejs请求跨域解决

前端提示请求跨域的问题

1.安装cors

npm install cors

2.允许所有网站访问

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

3.指定网站访问

const cors = require('cors');
app.use(cors({
    origin: 'http://127.0.0.1:8080'
    credentials: true
    methods: 'GET,POST,PUT,DELETE'
    allowedHeaders: 'Content-Type,Authorization'
    exposeHeaders: 'Content-Type,Authorization' 
}))

4.指定网站访问多个

const cors = require('cors');
const whitelist = ['域名1','域名2','域名3'];
const corsOptions = {
  origin: (origin, callback) => {
    // 允许没有 origin 的请求(如 Postman)
    if (!origin) return callback(null, true);
    
    if (whitelist.includes(origin)) {
      callback(null, true);
    } else {
      callback(new Error('Not allowed by CORS'));
    }
  },
  credentials: true
};
app.use(cors(corsOptions))