Javascript实现网络监测的方法

(function(){
var work = function(){
 var monitor = this;
 /
   @param {Funcation} speedInterval
  /
 var speedInterval = null;
 /
   @param {Function} workInterval
  /
 var workInterval = null;
 /
   @param {Function} reNetworkInterval
  /
 var reNetworkInterval = null;
 var time = 5000;
 /
   获取网络连接状态
  /
 var getConnectState = function(){
  return navigator.onLine ? 1 : 0;
 }; 
 /
   网络中断
  /
 var disconnect = function(){
  // TODO ... 
  console.log("网速中断");
  window.clearInterval(reNetworkInterval);
  reNetworkInterval = null;
  endSpeed();
  endNetwork();
  window.setTimeout(function(){
   reNetworkInterval = window.setInterval(function(){
    if (getConnectState() == 1) {
     window.clearInterval(reNetworkInterval);
     reNetworkInterval = null;
     startSpeed();
     startNetwork();
    } else {
     window.clearInterval(reNetworkInterval);
     reNetworkInterval = null;
     disconnect();
    }
   }, time);
  }, 2  time);
 };
 /
   网络速度
  /
 var speed = {
   /
     网速过慢
    /
   bad : function(){
    // TODO ... 
    console.log("网速过慢");
    window.setTimeout(function(){
     if(getConnectState() == 1) {
      window.clearInterval(workInterval);
      workInterval = null;
      startSpeed();
     } else {
      disconnect();
     }
    }, 2  time);
   },
   /
     网速中等
    /
   medium : function(){
    // TODO ... 
    console.log("网速中等");
   },
   /
     网速极佳
    /
   great : function(){
    // TODO ... 
    console.log("网速极佳");
   }
 };
 /
   开启速度监测
   @private
  /
 var startSpeed = function(){
  window.clearInterval(speedInterval);
  speedInterval = null;
  if(getConnectState() == 1) {
   speedInterval = window.setInterval(function(){
    var start = new Date().getTime();
    if (getConnectState() == 1) {
     var img = document.getElementById("workSpeedImage");
     if (!!!img) {
      img = document.createElement("IMG");
      img.id = "workSpeedImage";
      img.style.display = "none";
      document.body.appendChild(img);
     }
     try {
      img.src = "http://.baidu./img/baidu_jgylogo3.gif?_t=" + new Date().getTime();
      img.onload = function(){
       var end = new Date().getTime();
       var delta = end - start;
       if (delta > 200) {
        speed.bad();
       } else if (delta > 100) {
        speed.medium();
       } else {
        speed.great();
       }
      };
     } catch(e){
      speed.bad();
     }
    } else {
     // TODO 网络断开
     disconnect();
    }
   }, time);
  }else {
   // TODO 网络断开
   disconnect();
  }
 };
 /
   停止速度监测
   @private
  /
 var endSpeed = function(){
  window.clearInterval(speedInterval);
  speedInterval = null;
 };
 /
   开启网络连接监测
   @private
  /
 var startNetwork = function(){
  if (getConnectState() == 1) {
   workInterval = window.setInterval(function(){
    if (getConnectState() == 0) {
     disconnect();
    }
   }, time);
  } else{
   disconnect();
  }
 };
 /
   结束网络连接监测
   @private 
  /
 var endNetwork = function(){
  window.clearInterval(workInterval);
  workInterval = null;
 };
 /
   网络监控开始
  /
 this.start = function(){
  startNetwork();
  startSpeed();
 };
 /
   停止网络监控
  /
 this.s = function(){
  endSpeed();
  endNetwork();
 };
};
  window.work = new work();
}).call(this);
// 调用的时候,直接调用work.start();