1. Shootout! Template
engines for the JVM
Jeroen Reijn | @jreijn | #jfall13

2. About me
• Engineer @ Hippo (CMS)
• Worked on web based platforms since
2001 with PHP, XSLT, JSP,Velocity and
Freemarker
• Blogger at http://blog.jeroenreijn.com

3. Session agenda
• General overview
• Interesting template engines
• Benchmark project
• Performance results

4. Template engine?
• What is a Template ?
• What is a Template Engine ?
• How many Java Template Engines ?
• Java-Source.net : 21
• Wikipedia: 17

5. Most commonly used
• JSP
• Freemarker
• Velocity

6. Overview

7. Selection criteria
• Project activity
• Framework support
• Active Community
• Brings added value
• IDE support

8. Most interesting
• Thymeleaf
• Mustache
• Jade
• Scalate

9. Thymeleaf

10. Overview
• Available at http://www.thymeleaf.org/
• Java, DOM based template engine
• XML / XHTML / HTML5
• Full Spring MVC integration
• ‘Natural templating’

11. Natural templating
• From Wikipedia:
“The template can be a document as valid as
the final result, the engine syntax doesn't
break the document's structure”

12. JSP in browser

13. Thymeleaf in browser

15. Variables & Loops
• Variables
• Loops

16. Fragments
• Include fragment
• Define fragment based on th:fragment

17. {{ Mustache }}

18. Overview
• Available at https://mustache.github.com
• “logic-less” because there are no control
statements (i.e. if, else, loops, etc)
• Tags are specified using {{ }} (looks like a
mustache)
• Implemented by many languages: Java, Ruby,
JavaScript, Python, Erlang, PHP, Objective-
C, .NET, C++, Go, ColdFusion, Scala, etc.

19. Overview
• Java implementations:
• JMustache
• Mustache.java
• Not web specific
• Spring MVC integration as an 3th party
add-on

20. Variables
{
“greeting” : “Hello”,
“message” : “World”
}
{{greeting}} {{message}}
Data Template
Hello World
Output

21. Sections
{
"repo": [
{ "name": "resque" },
{ "name": "hub" },
{ "name": "rip" },
]
}
{{#repo}}
<li>{{name}}</li>
{{/repo}}
Data Template
<li>resque</li>
<li>hub</li>
<li>rip</li>
Output

22. Fragments
base.mustache:
<h2>Presentations</h2>
{{#presentations}}
{{> presentation}}
{{/presentations}}
presentation.mustache:
<h3>{{title}}</h3>
<p>{{startTime}}</p>
Template

23. Jade

24. Jade
• Available at http://jade-lang.com
• Node.js Template engine
• Java Implementation: Jade4j
• Compact notation

25. Syntax

26. Result

27. Variables & Iterations
• Variables
• Iterations

28. Fragments

30. Overview
• Available at http://scalate.fusesource.org/
• Scala based Template Engine (ScalaTE)
• Templates are compiled as Scala objects
• Equivalent to using JSP, JSTL, JSP EL & Tiles /
Sitemesh
• Integration available for Spring, Play, Lift, ...

31. Template languages
• SSP (Scala Server Pages)
• SCAML (based on Ruby’s HAML)
• Mustache
• Jade

32. Scaml
• Based on HAML (HTML abstraction
markup language)
• Integrates Scala code
• Well formatted markup
• Similar to Jade

33. Variables & Loops
• Fragment support is possible
• Inline Scala code

34. Benchmark project

35. Benchmark project
• Simple Spring MVC application
• Multiple view resolvers
• Page that show a list of presentations
• Uses page layouts / fragments
• Uses i18n where possible

36. Spring MVC

37. public class Presentation {
private Long id;
private String title;
private String speakerName;
private String summary;
private String room;
private Date startTime;
private Date endTime;
}

39. Project available
• Project will be available as open source on
github.
• https://github.com/jreijn/spring-comparing-
template-engines

40. Results!

41. Performance
0,00s
3,57s
7,14s
10,71s
14,29s
17,86s
21,43s
25,00s
Total time taken for 25.000 requests (less is better)
Thymeleaf - v2.1.0
Jade4j - v0.3.17
Scalate - v1.6.1
Mustache - v1.8
Freemarker - v2.3.19
Velocity - v1.7
JSP - 2.1
* All tests were local, on hardware from 2010. Results might differ based on the actual implementation.
For the latest results check the GitHub project from slide 39.

42. Findings
• Thymeleaf used more memory and was
slower then the commonly used, but seems
great for the web.
• When using ‘layouts’ instead of includes,
Scalate was a factor 4 slower.
• Mustache performed really well!

43. Tips
• If you want designers to own your templates
consider Mustache or Thymeleaf
• If you want developers to own your templates:
• If you want to generate HTML / XML and DRY?
=> Jade
• otherwise: JSP, Freemarker, etc

44. Thank you!
Questions?
@jreijn
j.reijn@onehippo.com