wap2app出现 UniPlusBridge is not defined 错误

代码如下：

  <script type="text/javascript" src="https://js.cdn.aliyun.dcloud.net.cn/dev/uni-app/uni.webview.1.5.2.js"></script>  
  <script type="text/javascript">  
    document.addEventListener('UniAppJSBridgeReady', function () {  
      uni.webView.getEnv(function (res) {  
        console.log('当前环境：' + JSON.stringify(res));  
      });  
      uni.webView.navigateTo({  
        url: "https://baidu.com"  
      })  
    });  
  </script>

错误提示：
11:34:49.449 当前环境：{"plus":true} at http://192.168.1.114:8080/:49
11:34:49.469 Uncaught ReferenceError: UniPlusBridge is not defined at http://192.168.1.114:8080/:1