index.html

<!DOCTYPE HTML>
<html>
   <head>
   <meta charset="utf-8">
   <script src="https://cdn.bootcss.com/jquery/3.4.1/jquery.min.js"></script>
      <script type="text/javascript">
      var reader = { 
  readAs: function(type,blob,cb){
	var r = new FileReader();
	r.onloadend = function(){
      if(typeof(cb) === 'function') {
        cb.call(r,r.result);
      }
    }
    try{
      r['readAs'+type](blob);
    }catch(e){}
  }
}

function parseBlob(blob){
  var stringVar;
  reader.readAs('Text',blob.slice(16,blob.size,'text/plain;charset=UTF-8'),function(result){
    stringVar = result;
    console.log(stringVar);
    $(document).ready(function(){
    $("ol").append( "<li>" + stringVar + "</li>");
    });
  });
}
               // 打开一个 web socket
               var ws = new WebSocket("ws://127.0.0.1:8999");                
               ws.onopen = function()
               {
                  // Web Socket 已连接上，使用 send() 方法发送数据
                  console.log('ok');
               };
                
               ws.onmessage = function (evt) 
               { 
                  var received_msg = evt.data;
                  parseBlob(received_msg);
                  
               };
                
               ws.onclose = function()
               { 
                  // 关闭 websocket
                  alert("连接已关闭..."); 
               }; 

      </script>
        
   </head>
   <body>
   
      <div id="sse">
        test
      </div>
      <ol><li>list<li</ol>
   </body>
</html>