node实现跨域get,post

// Access-Control-Allow-Origin
app.all('*', function(req, res, next) {
    res.header("Access-Control-Allow-Origin", "*");
    res.header("Access-Control-Allow-Headers", "X-Requested-With,Content-Type");
    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();
});