[node]启动一个简单的node接口

// 复制这个文件到目录，再输入一下命令：
// npm i express
// node nodeServer.js
// 启动之后可以通过浏览器尝试访问：    localhost:3000/123


var express = require('express');
var app = express();

//----------------------------------------------------------
// 设置跨域访问

app.all('*', function (req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "X-Requested-With");
    res.header("Access-Control-Allow-Methods", "PUT,POST,GET,DELETE,OPTIONS");
    res.header("X-Powered-By", ' 3.2.1');
    res.header("Content-Type", "application/json;charset=utf-8");
    next();

});
//-----------------------------------------------------------
// 测试新建一个接口
var questions = [
    {
        data: 213,
        num: 444,
        age: 12
    },
    {
        data: 456,
        num: 678,
        age: 13
    }
];

// 写个接口123
app.get('/123', function (req, res) {
    res.status(200), res.json(questions)

});

// 配置服务端口3000
var server = app.listen(3000, function () {
    var host = server.address().address;
    var port = server.address().port;
    console.log('Example app listening at http://%s:%s', host, port);

})