asynchronous widget JSP foreach (Java EE applicati

Question

I have the following code in a JSP page:

<c:forEach var="widget" items="${widgets}">
        <p><h2>Widget</h2></p>
        <p>IDType: ${widget.id}</p>
        <p>Name: ${widget.name}</p>  
</c:forEach>

At the moment it is only text that will be displayed, but in the future there will be charts and images as well. I would like to use asynchronous loading, so the page doesn't have to wait on the largest images/charts. On the internet I found tutorials for Java code, but not for JSP pages. What is the best way to implement asynchronous loading in JSP pages?

Thanks!

Answer 1

Simply generate these images and charts separately using different servlet:

<c:forEach var="widget" items="${widgets}">
    <p><h2>Widget</h2></p>
    <p>IDType: ${widget.id}</p>
    <p>Name: ${widget.name}</p>  
    <img src="chart-servlet.png?id=${widget.id}"/>
    <img src="image-servlet.png?id=${widget.id}"/>
</c:forEach>

On the server side map some servlets to chart-servlet.png and image-servlet.png. You can then use id parameter to generate appropriate chart or image. From the browser perspective it first renders DOM without images to then ask server for external resources (images).