Javascript监测网络状况详解编程语言

  
(function(){ 
var network = function(){ 
    var monitor = this; 
       
    /** 
     * @param {Funcation} speedInterval 
     */ 
    var speedInterval = null; 
    /** 
     * @param {Function} networkInterval 
     */ 
    var networkInterval = 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(networkInterval); 
                        networkInterval = 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("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(); 
        } 
    }; 
       
    /** 
     * 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) { 
            networkInterval = window.setInterval(function(){ 
                if (getConnectState() == 0) { 
                    disconnect(); 
                } 
            }, time); 
        } else{ 
            disconnect(); 
        } 
    }; 
       
    /** 
     * 结束网络连接监测 
     * @private  
     */ 
    var endNetwork = function(){ 
        window.clearInterval(networkInterval); 
        networkInterval = null; 
    }; 
    /** 
     * 网络监控开始 
     */ 
    this.start = function(){ 
        startNetwork(); 
        startSpeed(); 
    }; 
    /** 
     * 停止网络监控 
     */ 
    this.stop = function(){ 
        endSpeed(); 
        endNetwork(); 
    }; 
}; 
     window.network = new network(); 
}).call(this); 
   
   
// 调用的时候,直接调用network.start();