嵌套调用，上一个结果是后一个函数的请求参数，或者所有的函数完成之后才能去做一件事 例子：

    var Q = require("q");
              var fun1 = function (data) {
              var deferred = Q.defer();
              deferred.resolve(data+" fun1");
              return deferred.promise;
              }
    
  var fun2 = function (data) {
          var deferred = Q.defer();
          deferred.resolve(data+" fun2");
          return deferred.promise;//返回的是promise对象 这里的resolve的结果将作为下一个promise的参数结果
  }

var fun3 = function (data) {
        var deferred = Q.defer();
        deferred.resolve(data+" fun3");
        return deferred.promise;
}

var fun4 = function (data) {
            var deferred = Q.defer();
            deferred.resolve(data+" fun4");
            return deferred.promise;
}

function main(data,cb){
          fun2("test")
          .then(fun3)
          .then(fun4)
          .done(function(data){//.done用来返回最终的结果
          console.log(data);//test fun2 fun3 fun4
          },function(err){
            //failed
          });
}
  function main2() {
        Q.all([
              fun1("test1"), fun2("test2"), fun3("test3")
             ]).spread(function () {
                             console.log(arguments);
                            //结果如下： { '0': 'test1 fun2', '1': 'test2 fun3', '2': 'test3 fun4' }
                        });
   }
 main();
 main2();
          **上述直接运行即可。**（ps:上面只是个例子，下面部分是初步调用的具体例子)

=====================================================================================

  下面是对微信请求接口的一个封装，用的就是Promise的思想。
var http=require("https");
var parse = require('url').parse;
var setting = require('../setting.js');
var iconv = require('iconv-lite');
var Q = require("q");
//任用promise 思想来处理回调函数
    function get(url){
      var info=parse(url);
      var deferred = Q.defer();
      var options = {
      hostname: info.hostname,
      port: info.port,
      path: info.path,
      method: 'GET'
      };
      var req = http.request(options, function (res) {
                    res.on('data', function (chunk) {
                    deferred.resolve(chunk);
                    });
                  });

        req.on('error', function (e) {
        deferred.register();
        });
       req.end();
       return deferred.promise;
 }
 
var getAcToUrl=function(){
        var acToUrl='https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid='+setting.appid+'&secret='+setting.secret;
        return get(acToUrl);
}

var getTicketUrl= function(data){
          var data=JSON.parse(iconv.decode(data,"UTF-8"));
          var ticketUrl="https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token="+data.access_token+"&type=jsapi";
          return get(ticketUrl);
  }
  
  var getMessage=function(callback){
    getAcToUrl().then(getTicketUrl).done(callback);
}

      exports.getMessage=getMessage;
  求批~~看各路大神有无其他方法。