关于localStorage的数据封装，以及快速使用.....

var _localStorage={
put:function(key,stringVal,time){
try{
if(!localStorage){return false;}
if(!time || isNaN(time)){time=60;}
var cacheExpireDate = (new Date()-1)+time*1000;
var cacheVal = {val:stringVal,exp:cacheExpireDate};
localStorage.setItem(key,JSON.stringify(cacheVal));//存入缓存值
}catch(e){}
},
get:function (key){
try{
if(!localStorage){return false;}
var cacheVal = localStorage.getItem(key);
var result = JSON.parse(cacheVal);
var now = new Date()-1;
if(!result){return null;}//缓存不存在
if(now>result.exp){//缓存过期
this.remove(key);
return "";
}
return result.val;
}catch(e){
this.remove(key);
return null;
}
},
remove : function(key){
if(!localStorage){return false;}
localStorage.removeItem(key);
},
clear : function(){
if(!localStorage){return false;}
localStorage.clear();
}
}