Question

On a JSTL/JSP page, I have a java.util.Date object from my application. I need to find the day after the day specified by that object. I can use <jsp:scriptlet> to drop into Java and use java.util.Calendar to do the necessary calculations, but this feels clumsy and inelegant to me.

Is there some way to use JSP or JSTL tags to achieve this end without having to switch into full-on Java, or is the latter the only way to accomplish this?

Answer 1

I’m not a fan of putting java code in your jsp.

I’d use a static method and a taglib to accomplish this.

Just my idea though. There are many ways to solve this problem.

public static Date addDay(Date date){    //TODO you may want to check for a null date and handle it.    Calendar cal = Calendar.getInstance();    cal.setTime (date);    cal.add (Calendar.DATE, 1);    return cal.getTime(); } 

functions.tld

<?xml version='1.0' encoding='UTF-8' ?> <taglib xmlns='http://java.sun.com/xml/ns/j2ee'   xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance'   xsi:schemaLocation='http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/web-jsptaglibrary_2_0.xsd'   version='2.0'>   <description>functions library</description>   <display-name>functions</display-name>   <tlib-version>1.1</tlib-version>   <short-name>xfn</short-name>   <uri>http://yourdomain/functions.tld</uri>   <function>     <description>       Adds 1 day to a date.     </description>     <name>addDay</name>     <function-class>Functions</function-class>     <function-signature>java.util.Date addDay(java.util.Date)</function-signature>     <example>       ${xfn:addDay(date)}     </example>   </function> </taglib>