nodejs集成环信服务器怎么获取token

var http_request = function (json) {

	var json = json || {};

    json.data = json.data || {};

    json.method = json.method || 'GET';

	json.headers = json.headers || {};

	json.headers['Content-Type']='application/json';

	//json.headers['http']='multipart/form-data';

	json.headers['Authorization']='Bearer '+token;

	

    var postData = JSON.stringify(json.data);//从json对象中解析出字符串

    //请求参数

    var options = {

        host: 'a1.easemob.com',

        path: '/xxx/xxx' + json.path,

        method: json.method,

        headers:json.headers

    };

    //发送请求

    var req = https.request(options, function (res) {

        var chunks = '';

        var size = 0;

        res.setEncoding('utf8');//设置返回内容的编码

		//存储返回的响应数据

        res.on('data', function (chunk) {

            chunks+=chunk;

            size += chunk.length;

        });

        res.on('end', function () {

			//响应完成，获取完整响应数据

            //var data = JSON.parse(Buffer.concat(chunks, size).toString());

            if (typeof json.callback=='function')

                json.callback(chunks);

        });

    });

	//请求错误时执行的方法

    req.on('error', function (e) {

        console.log('problem with request: ' + e.message);

    });



    // write data to request body

    req.write(postData);//请求体

    req.end();//请求结束

};





//---------------------------------------------------用户体系集成





//获取token

function getToken(callback) {

    var data = {grant_type: 'client_credentials', client_id: client_id, client_secret: client_secret};

	http_request({

		data:data,

		path:'/token',

		method:'POST',

		callback:function (data) {

			var d=JSON.parse(data);

			var token = d.access_token;

			//console.log(data);

			//传进来的函数用来接数据

			if(typeof callback == 'function')

				callback(token);

			

		}	

	});

	

};