private WVJBMessage JSONObject2WVJBMessage(JSONObject jo) {
        WVJBMessage message = new WVJBMessage();
        try {
            if (jo.has("callbackId")) {
                message.callbackId = jo.getString("callbackId");
            }
            if (jo.has("data")) {
                message.data = jo.get("data");
            }
            if (jo.has("handlerName")) {
                message.handlerName = jo.getString("handlerName");
            }
            if (jo.has("responseId")) {
                message.responseId = jo.getString("responseId");
            }
            if (jo.has("responseData")) {
                message.responseData = jo.get("responseData");
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }
        return message;
    }
set a listener for javascript closing the current activity.
app/src/main/java/com/example/jingbin/webviewstudy/view/WVJBWebView.java