Daily Archives: March 17, 2011

Testing java ee applications – the server side java symposium

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This session was also fast moving and information filled, but it didn’t feel as overwhelming as the Spring session. The presenter included demos of some of the technologies.  He did use the term “unit test” for things that test through the web and database. I would rather these be called integration/functional tests. I wish the testing industry would use one set of definitions. I subscribe to the one where a unit test doesn’t involve the database or the server

Servlet layer

  • Junit – need to build on
  • httpunit – higher level api on http level – the demo shows creating requests and responses using the java api. This technology is preferred over htmlunit because you are usually not generating raw html if you are using a servlet.  [you should be using MVC]
  • htmlunit – higher level api on html level
  • Cactus – in container tests, good for functional testing
  • Selenium – can be used for acceptance testing by users, no coding required
  • Servletunit gives you a simulated container or can mock the request/response objects for simple cases

JSF

  • Jsf 2 project stages help for debugging and testing. This helps because you can easily specify different web.xml settings.
  • Selenium – for simple cases
  • jsfunit – uses cactus, junit, httpnit and htmlunit behind the scenes

Tip: define ids in your jsf tags so not randomly generated. That way you can refer to them

CDI/EJB 3.1

  • Arquillian – lets you say you do not want your whole aoo to be deployed. You use @RunAs(Arquillian.class). Then you can createDeployment() with the classes you want deployed. the ShrinkWrap API lets you add specific classes which lets you test one EJB or injected element.  The demo used embedded glassfish as specified by a Maven profile.  Also lets you inject into the unit test
  • Apace myfaces codi testing is a competing choice
  • For simple cases mock objects are sufficient, not testing production environment [that is why you test logic in unit tests and environment in integration tests which are in container]
  • @RunWith(ResinBeanContainerRunner) starts a very light container. Only supports CDI and EJB 3.1 lite

JPA

  • Embedded database – derby, hsql, java db
  • Embedded container like arquillian
  • Dbunit – helps with data consistency [and setup]
  • ejb3junit, mocks or pure junit again works for simple cases

Web Services

  • Soapui – good for complex cases with either SOAP or REST. Same level as Selenium
  • Can use junit and arquillian if want test to be self contained
  • Can use jersey test framework

Live from TSSJS – Web Frameworks with Matt

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Live blogging from TheServerSide Java Symposium again, this time with Matt Raible, who is giving a presentation entitled “Comparing JVM Web Frameworks”.  He began his talk taking feedback from the audience on what frameworks people are using, with one humerous dialogue that proceeded as follows:

“How many people are using Struts 1?”.
One gentleman raises his hand.
“Poor bastard.  Are you using Struts with WebSphere?”
The gentleman nodded.
“Why haven’t you quit your job yet?”

1.  Web Frameworks – Too many?
In the non-Java market, jQuery has risen to the top but this hasn’t happened in the Java world.  Some people have criticized Java as having too many frameworks to choose from.

Matt is personally very much against Struts 1, as well as JSF.  He talks about how the founder of both, Craig McClanahan has essentially ditched Struts/JSF for Rails in around 2007.  He also quotes James Gosling as saying he hates JSF with a link to the YouTube video, although indicates he may have been referring to JSP.

2. Choosing a framework
Matt often talks about being asked which framework to use.  He has constructed a list of 20 criteria to determine which framework to use such as:

  1. Developer Productivity
  2. Developer Perception
  3. Learning Curve – Should be able to learn in under a week
  4. Project Health
  5. Developer Availability – Will you be able to find developers to hire who know the material?
  6. Job Trends
  7. Templating
  8. Components
  9. Ajax
  10. Plugins or Add-Ons
  11. Scalability
  12. Testing Support
  13. i18n and testing
  14. Validation
  15. Multi-language Support
  16. Quality of Documentation/Tutorials
  17. Books Published
  18. REST Support (client and server)
  19. Mobile / iPhone Support
  20. Degree of Risk

Matt reviewed a number of platforms and posted the resulting matrix online.  The top 5 ones based on these scores are Grails, Tapestry, Lift, Spring, and Struts2.  Often the 5, 6, and 7 providers change every few months.

3.  Business Decisions
Often companies hire consultants to reinforce web framework decisions that they have already made.  A lot of companies have a proprietary web framework that can be successful for their product.

4.  Controversary
Matt has been criticized for his scoring by members of the community.  He has posted a detailed explanation of how he calculated these ratings online.  As a well-read GWT developer, I disagree with some of his scores for GWT, especially templating which only scored a 0.5.

5. Matt’s favorite web frameworks

  1. Grails and Groovy:  Eeasy transition for Java developers.  It is also a gateway to Groovy.  He mentions some companies and developers resist Groovy because it is targeted only for Java developers and there isn’t a high availability of jobs.
  2. GWT:Great for Java developers who hate JavaScript.  The community is open and Google has done a good job growing a vibrant developer base.  The down sides, though, are that it is slow to test and requires Java knowledge to use.
  3. Ruby on Rails: Good for web developers, rather than hard-core Java developers.  The community is excellent.  The down sides is performance, testing, and type safety are limited.
  4. Spring MVC:  Easy configuration and usage
  5. VAADIN:  Excellent theme and layout support.  Uses the GWT API for developing view.
  6. WICKET:  Great for Java Developers.  Active community with creators providing a lot of support.  One downside is very little jobs available for WICKET developers.

Active Mailing Lists
One good measure of the health of a web framework is the number of developers asking questions and involved in the community, such as mailing lists and forum websites.  Some frameworks have hundreds of questions posted a month while others have 1-2 and are clearly not being used much.

Conclusion
Matt finished asking the question “What if there is no ‘best’ web framework?”, to which he spent time presenting competing argument about how people ‘shop’ for frameworks.  He compared shopping for frameworks with shopping for food and discussed an article with a researcher who did trending for how people choose food products.  “When we pursue universal principles in food, aka web services, we are doing ourselves a massive disservice”.  In other words, pick the frameworks that work for you, not neccesssarily the “best” framework.

Matt gave one of the best presentations I’ve attended at TheServerSide Java Symposium, and covered a large variety of web frameworks, while demonstrating expertise in each.  As a fellow consultant, I appreciate that he emphasized how quickly it is to pick up these frameworks as well as how easy it is to find a job with these skills.  At one point, he was one of only 3 active GWT developers in the Denver area and would get a call anytime there was a GWT job available.

Side note:  Matt recommends all Java developers learn about and know JRebel given its power, saying if you take away only one thing from this presentation it is that you should know JRebel.

Static analysis for performance – the server side java symposium

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Overall, I was disappointed by the session. Most of it was about the performance anti-patterns and i was expecting more about the static analysis tool. There was only one slide with an example of how to detect a pattern using static analysis and I found it hard to understand,  It is easy to say to tell new developers not to do something.  It is hard to detect programatically.   Nevertheless, the points made are valid and here are the notes.

Is Java slow? Not on Intel for C at least.

What are root causes of performance issues?

  • Bad architecture, code or design
  • Configuration
  • [or database/network and not java at all, but that’s out of scope here]
  • Many ways to write incorrect code. Static analysis is not a replacement for traditional performance tuning

Types of analysis:

  • Code query systems – Explore relationships among program elements, Codequest and jquery in this space
  • Semantic code query systens – focus on behavior in addition to structure.  Yonita is in this space.  Yonita starts with bytecode to capture all detail. Then query in sql or prolog to find anti-patterns
  • Note that yonita is a prototype and not yet publicly available

Redundant work
Examples

  • JSF calling output text and the getXXX<> method makes a database call each time
  • get value for key several time.  Ok if took like Hibernate is caching it for you
  • make the same ajax call twice and then do something different than the result

Fix by caching the value
Showed patterns for detecting, it looks complicated!

Other anti-patterns

  • Fine grained remote calls – entity beans versions 1 and 2
  • One by one processing – adding one at a time instead of batching so the transaction, authorization and database all happen repeatedly
  • Return a lot of records and discard the results

I asked if the static analysis tools could detect all of the anti-patterns shown. The answer was that it is library specific. I didn’t get a clear yes or no as to whether one could write a rule.

Someone asked about complex configurations. The answer was the tools struggle with dynamic configuration like Spring and specific support of the tool is required.