Prev Next

API / Apache Velocity Interview questions

What is a Velocimacro (#macro directive)?

A Velocimacro is a reusable block of VTL defined once with #macro and then invoked like a function elsewhere in templates. It's Velocity's main mechanism for avoiding copy-pasted markup.

#macro(greet $name $formal)
  #if($formal)
    Dear $name,
  #else
    Hi $name!
  #end
#end

#greet("Alex" true)
#greet("Sam" false)

Macros can be defined locally at the top of a single template (visible only within that template by default) or placed in a shared library file registered through the velocimacro.library property, which makes them available across every template the engine renders.

What is a Velocimacro used for?
How can a Velocimacro be made available across every template the engine renders?

More Related questions...

What is Apache Velocity? What are the main features of Apache Velocity? What is Velocity Template Language (VTL)? What file extension do Velocity templates typically use? What is the purpose of the VelocityContext? What are Velocity directives? What are the types of loops available in Velocity? How do you use variable references in Velocity templates? How do you apply conditional logic in a Velocity template? Define the #set directive in Velocity? Describe the role of the VelocityEngine class? List the comment syntax options available in VTL? Explain the purpose of the #include directive? What is the purpose of the #parse directive? What is a Velocimacro (#macro directive)? What is the purpose of the #stop directive? What is silent/quiet reference notation ($!) used for? How do you use the #break directive? What are formal vs shorthand references in VTL? How do you render array or list elements with #foreach? Why is Velocity described as a "template engine" rather than a full programming language? Why do we use Velocity instead of embedding logic in JSP? Why should you avoid putting business logic inside Velocity templates? Why doesn't Velocity throw an exception by default for an undefined reference? How does Velocity resolve a variable reference at render time? How is Apache Velocity different from Apache FreeMarker? When should you use #parse over #include? When would you choose a Velocimacro over a Java-side helper method? What happens when a referenced property or method doesn't exist on an object in a template? What is the difference between #set($x = $y) and context.put("x", y) in Java code? Which is better for reusable rendering logic: a Velocimacro or a custom Directive class, and why? How can you optimize Velocity template rendering performance? How do you troubleshoot a "parse error" in a VTL template? Explain the lifecycle of a Velocity template from load to render? What is the difference between local and global (library) Velocimacros? What is strict reference mode in Velocity, and how does it differ from the default lenient mode? How does Velocity integrate with the Apache Struts framework? How does Velocity handle null values inside #if conditions and references? What is the RuntimeInstance in Velocity's architecture? What is the role of the ResourceManager and ResourceLoader in Velocity? How do you configure a custom template ResourceLoader in Velocity? What is the difference in templating philosophy between Apache Velocity and Thymeleaf? How do you escape special characters like $ and # in a Velocity template? What are Velocity Tools (VelocityTools) and why would you use them? How do you handle internationalization (i18n) in Velocity templates? Explain the internal working of Velocimacro resolution and invocation? Explain the internal working of the Velocity template parsing process? What security risks are associated with allowing untrusted users to submit Velocity templates? What is the Uberspector in Velocity and what problem does it solve? Why is Apache Velocity often considered a legacy choice for new Java projects today?
Show more question and Answers...

BigData

Comments & Discussions

Interviews Questions

About Javapedia.net

Javapedia.net is for Java and J2EE developers, technologist and college students who prepare of interview. Also this site includes many practical examples.

This site is developed using J2EE technologies by Steve Antony, a senior Developer/lead at one of the logistics based company.

Follow Javapedia updates

contact: javatutorials2016[at]gmail[dot]com

Kindly consider donating for maintaining this website. Thanks.

Copyright © 2026, javapedia.net, all rights reserved. · .

DMCA.com Protection Status