/*用export把方法暴露出来*/
/*设置cookie*/
export function setCookie(c_name,value,expire) {
  var date=new Date()
  date.setSeconds(date.getSeconds()+expire)
  document.cookie=c_name+ "="+escape(value)+"; expires="+date.toGMTString()
  //console.log(document.cookie)
}
/*获取cookie*/
export function getCookie(c_name){
  if (document.cookie.length>0){
    let c_start=document.cookie.indexOf(c_name + "=")
    if (c_start!=-1){ 
      c_start=c_start + c_name.length+1 
      let c_end=document.cookie.indexOf(";",c_start)
      if (c_end==-1) c_end=document.cookie.length
        return unescape(document.cookie.substring(c_start,c_end))
      } 
    }
  return ""
}
/*删除cookie*/
export function delCookie(c_name){
  setCookie(c_name, "", -1)
}

methods:{
 submit(){
       setCookie('username',username,1000*60)
    axios.get('http://172.16.2.43:8080/static/data/mt_index.json').then((res)=>{ 
   this.$router.push({
          path: '/user', query:{userid: $("input[name='username']").val()}
         }); 
         //this.setuserid($("input[name='username']").val());        
  }) 
 }
}

<div class="topheader">
  <span class="location fl">北京</span>
  <div class="search-box">
     <a href=""><input type="text"></a>      
  </div>
  <span class="mine" @click="jampmin">我的</span>
</div>
jampmin(){
  //获取cookie值
  var username=getCookie('username');
  if(username==''||username=='undefind'){
   this.$router.push({
        path: '/login'
      });
  }else{
   this.$router.push({
        path: '/user'
      });
  }     
} 

 <p @click="signout()" class="signout">退出</p>
signout(){
  /*删除cookie*/
  delCookie('username');
  this.$router.push({
    path: '/index'
  });
}