Hide a HTML button based on a if-condition

问题

I have a JSP page which includes a button called "Download".I want to hide this button based on a if-condition.

The Download button is meant to generate and download PDF onclick of it.

I have a List that is being fetched from the Controller and if this list is empty, I want to hide the "Download" button on the JSP page.

This is my button,

<button type="button" class="btn bg-red waves-effect" onclick="ExportPdf()">Download</button>  

I want to hide the button if the List is empty.

回答1:

Display when list isn't empty:

<% if (!list.isEmpty()){ %>
<button type="button" class="btn bg-red waves-effect" onclick="ExportPdf()">Download</button>  
<% } %>

For example if you fetch list from attribute

ArrayList<String> list = (ArrayList<String>) request.getAttribute("listName");

来源：https://stackoverflow.com/questions/56236527/hide-a-html-button-based-on-a-if-condition