解决NodeJS+Express模块的跨域访问控制问题：Access-Control-Allow-Origin

在一个项目上想用NodeJS，在前端的js（http://localhost/xxx）中ajax访问后端RestAPI(http://localhost:3000/….)时(Chrome)报错：

XMLHttpRequest cannot load http://localhost:3000/auth/xxx/xxx. Origin http://localhost is not allowed by Access-Control-Allow-Origin.

解决代码：

方案一：

1. var express = require('express');
2. var app = express();
3. //设置跨域访问
4. app.all('*', function(req, res, next) {
5. res.header("Access-Control-Allow-Origin", "*");
6. res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");
7. res.header("Access-Control-Allow-Methods","PUT,POST,GET,DELETE,OPTIONS");
8. res.header("X-Powered-By",' 3.2.1')
9. res.header("Content-Type", "application/json;charset=utf-8");
10. next();
11. });
12. app.get('/auth/:id/:password', function(req, res) {
13. res.send({id:req.params.id, name: req.params.password});
14. });
15. app.listen(3000);
16. console.log('Listening on port 3000...');

方案二：

1. var express = require('express');
2. var app = express();
3. app.get('/auth/:id/:password', function(req, res) {
4. res.header("Access-Control-Allow-Origin", "*");   //设置跨域访问
5. res.send({id:req.params.id, name: req.params.password});
6. });
7. app.listen(3000);
8. console.log('Listening on port 3000...');