stomp.js直接连接RabbitMQ，连接成功后用subscribe订阅时报连接失败：precondition_failed

Question

var ws = new WebSocket('ws://192.168.11.91:15674/ws');
// 获得Stomp client对象
var client = Stomp.over(ws);
this.client = client;

this.client.heartbeat.outgoing = 0;
this.client.heartbeat.incoming = 0;
var self = this;

// 定义连接成功回调函数
var on_connect = function(x) {
    console.log('RabbitMQ 连接成功');
    self.client.subscribe("o.u."+this.currentUser.userId, this.handleMessage);
};

// 定义错误时回调函数
var on_error =  function(err) {
     console.log('RabbitMQ 连接失败：' + err);
};

// 连接RabbitMQ
 this.client.connect('admin', 'guoguo', on_connect, on_error, '/');

求教是哪里的问题？