//设置服务器跨域权限
app.use(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");
    next();
});

app.all('/test', function(req, res, next) {

  res.header("Access-Control-Allow-Origin", "*");

  res.header('Access-Control-Allow-Methods', 'PUT, GET, POST, DELETE, OPTIONS');

  res.header("Access-Control-Allow-Headers", "X-Requested-With");

  res.header('Access-Control-Allow-Headers', 'Content-Type');

  next();

});