Jakarta Struts Cookbook

3.16. Adding Request Parameters to a Link

Problem

You want to add an arbitrary set of request parameters to a hyperlink or URL created using the Struts html:link or html:rewrite tags.

Solution

Create a java.util.HashMap as a page-context bean using the jsp:useBean tag. Populate the map using the JSTL c:set tag. Then reference the created map using the name attribute of the html:link and html:rewrite tags:

<%@ taglib prefix="c"    uri="http://java.sun.com/jstl/core" %>
<%@ taglib prefix="html" uri="http://jakarta.apache.org/struts/tags-html" %>

<!-- header stuff here -->

<jsp:useBean id="params" class="java.util.HashMap"/>

<c:set target="${params}" property="user" value="${user.username}"/>
<c:set target="${params}" property="product" value="${product.productId}"/>
<html:link action="/BuyProduct" name="params">Buy Product Link</html:link>
<a href="javascript:window.open( 
        <html:rewrite action='/BuyProduct' name='params'/>)">
    Buy Product Popup
</a>

Discussion

The Struts html:link and html:rewrite tags allow you to add name/value parameters to the generated URL by referring to a Map property of a JavaBean. The map key is the parameter name and the map value is the parameter value.

While this approach is functional, it smells like a hack. You are forced to create Java code to represent something used only used to create an HTML link. Granted, the data comes from your business objects—which is the Model—but the parameter names are purely part of the View. A more practical problem with this approach ...