Javascript实现网络监测的方法

本文实例讲述了Javascript实现网络监测的方法。分享给大家供大家参考。具体实现方法如下：

该代码可监测网络是否连接及网速的快慢状态。

(function(){
var network = function(){
 var monitor = this;
 
 var speedInterval = null;
 
 var networkInterval = null;
 
 var reNetworkInterval = null;
 var time = 5000;
 
 var getConnectState = function(){
  return navigator.onLine ? 1 : 0;
 }; 
 
 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);
 };
 
 var speed = {
   
   bad : function(){
    // TODO ... 
    console.log("网速过慢");
    window.setTimeout(function(){
     if(getConnectState() == 1) {
      window.clearInterval(networkInterval);
      networkInterval = null;
      startSpeed();
     } else {
      disconnect();
     }
    }, 2 * time);
   },
   
   medium : function(){
    // TODO ... 
    console.log("网速中等");
   },
   
   great : function(){
    // TODO ... 
    console.log("网速极佳");
   }
 };
 
 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("networkSpeedImage");
     if (!!!img) {
      img = document.createElement("IMG");
      img.id = "networkSpeedImage";
      img.style.display = "none";
      document.body.appendChild(img);
     }
     try {
      img.src = "http://www.baidu.com/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();
  }
 };
 
 var endSpeed = function(){
  window.clearInterval(speedInterval);
  speedInterval = null;
 };
 
 var startNetwork = function(){
  if (getConnectState() == 1) {
   networkInterval = window.setInterval(function(){
    if (getConnectState() == 0) {
     disconnect();
    }
   }, time);
  } else{
   disconnect();
  }
 };
 
 var endNetwork = function(){
  window.clearInterval(networkInterval);
  networkInterval = null;
 };
 
 this.start = function(){
  startNetwork();
  startSpeed();
 };
 
 this.stop = function(){
  endSpeed();
  endNetwork();
 };
};
  window.network = new network();
}).call(this);
// 调用的时候,直接调用network.start();

希望本文所述对大家的javascript程序设计有所帮助。