Lessons learned Seam 2.2 project

Quick post with some bullet points of lessons learned during my last (and first) Seam project:

• Seam 2.2
• Hibernate 3.3.1
• JEE 5
• EJB 3.0
• JSF 1.2
• Richfaces 3.3
• JBoss 5.1
• Drools 5
• SQLServer 2008
• MySql 5.x
• TestNG
• Hudson

Seam
- To have a navigation for a method with a parameter like exportSelected(String value): see Seam navigation based on a function with parameters
- If your Seam app keeps re-deploying (restarting) when using JBoss within Eclipse: delete all files that end with 'dia' in your WEB-INF dir. See: Seam keeps redeploying For example, I modified pages.xml, which apparently created a pagesdia (or similar) file... after removing that one, it worked fine again.

Hibernate
- To see which validator fails on a persist():

try { entityManager.persist(verbinding); } catch (InvalidStateException e) { for (InvalidValue invalidValue : e.getInvalidValues()) { System.err.println("--------------> create(): exception Instance " + "of bean class: " + invalidValue.getBeanClass().getSimpleName() + " has an invalid property: " + invalidValue.getPropertyName() + " with message: " + invalidValue.getMessage()); } throw new RuntimeException(e); }

MySql
- To see data in better format in MySQL: show engine innodb status\G (so add the \G to a query)

Hibernate/JPA
- NamedQueries are loaded and parsed at startup time, so that's an advantage above em.createQuery() which are only parsed and evaluated at runtime. So with NamedQueries you get the errors sooner.

Drools
To solve this error in Drools decision table .XLS spreadsheet:

[testng] DEBUG [test.service.drools.DroolsHandling] getKnowledgeBase: getting path info from settings service [testng] DEBUG [test.service.drools.DroolsHandling] getting test.service.drools.DroolsHandling ruletable file: HandlingModelTest.xls [testng] DEBUG [test.service.drools.DroolsHandling] getKnowledgeBase: Trying to open a File [testng] WARN [jxl.read.biff.NameRecord] Cannot read name ranges for Excel_BuiltIn__FilterDatabase_1 - setting to empty [testng] WARN [test.service.drools.DroolsHandling] There are errors in the decision table file [testng] WARN [test.service.drools.DroolsHandling] Decision table error: message=[ERR 102] Line 9:16 mismatched input '"DroolsHandling6"' expecting ']' in rule "DroolsData_12" in pattern stringDataset [testng] WARN [test.service.drools.DroolsHandling] line: 9 [testng] WARN [test.service.drools.DroolsHandling] Decision table error: message=[ERR 102] Line 9:35 mismatched input '"Prefab"' expecting ']' in rule "DroolsData_12" in pattern stringDataset [testng] WARN [test.service.drools.DroolsHandling] line: 9 [testng] WARN [test.service.drools.DroolsHandling] Decision table error: message=[ERR 102] Line 22:16 mismatched input '"DroolsHandling6"' expecting ']' in rule "DroolsData_12" in rule "DroolsData_13" in pattern stringDataset [testng] WARN [test.service.drools.DroolsHandling] line: 22

Make sure your definition has all the cells merged that contain a condition! For example, check the red arrow pointing at the border of the cells between G9 and H9.

The last cell for the condition Prefab is not merged (i.e one cell) with all the other conditions. Here's now how it should be: see again the red arrow, there's no cell separation anymore, all condition columns are now merged into 1 cell.

- A space in a condition in a decision spreadsheet can cause a non-match! E.g GATE VALVE is not matched. Fixed it by always replacing a ' ' with an '_'.

Best of this Week Summary 1 February - 7 February 2010

• What's new in JSF 2.0 (facelets, composite components, partial state saving and Ajax).
  


• A couple of tips on how to avoid checking for null statements (focused on Java but applicable to any language).
  


• Tips/guidelines on how to use Spring on Google App Engine. Including a list of workarounds. This post has a more detailed step-by-step explanation for Spring 3.0 on GAE with a live example app.
  


• The work setup of several more or less famous technical guys ("nerds").
  

Best of this Week Summary 26 October - 01 November 2009

• Another good summary how merging WOA with SOA could potentially solve (some) SOA problems.
  


• This post covers three major areas of JavaScript/AJAX performance: distributed communication, usability, memory leaks and anti-patterns.
  


• Several interesting details from Facebook’s VP of Engineering about the infrastructure of the company, and the massive scaling problems it has to support. Big role for memcached there. Full video presentation here.
  


• Presentation at Oracle Open World 2009 - how to turn any ADF application into a SaaS application - an application suitable for deployment on the cloud. Includes short description of a SaaS, benefits, concerns, and several requirements. These requirements include customisation of fields shown to the user (e.g show or not show depending on the user or location) and i18n. Technologies suggested to achieve this are Oracle EBR, (WSRP) portlets, WebCenter, deep linking (tricky in JSF) and ESB.
  

Best of this Week Summary 27 April - 03 May 2009

• Already the fifth entry in a series on Wicket patterns and pitfalls.
  
  A PDF of presentation during TSSJS March 30 2009 on architecting applications using Wicket. Includes a short comparison to JSF.
  
  Here's eight areas to look into when considering using Wicket. Definitely don't forget to read the comments, because not all eight reasons are that valid. The same blogger also responds with a new article why he prefers Stripes over Wicket.
  


• Here's a presentation of Facebook's application stack during QCon SF 2008. In short: "Facebook runs a typical LAMP setup where P stands for PHP with certain customizations, and back-end services that are written in C++ and Java. Facebook has released some of the infrastructure components into the open source community, including the Thrift RPC framework and Scribe distributed logging server". Summary via Slashdot.
  


• An interesting new opensource technique developed by the guys from Digg for optimizing delivery of AJAX-enabled pages regarding the many HTTP requests needed and caching challenges.
  


• Interesting: a collaborative code review plug-in for Eclipse.
  


• A summary writeup of the Architect Summit 2008 can be found here.
  

Best of this Week Summary 16 March - 22 March 2009

• Great article by Dion Hinchcliffe with 10 emerging technologies every software architect has to know about. In short:
  
  
  1. Cloud computing
     
  
  
  2. Non-relational databases
     
  
  
  3. Next-generation distributed computing
     
  
  
  4. Web-oriented architecture (WOA)
     
  
  
  5. Mashups
     
  
  
  6. Open supply chains via APIs
     
  
  
  7. Dynamic languages (e.g Rails, PHP compared to Java/.Net)
     
  
  
  8. Social computing
     
  
  
  9. Crowdsourcing and peer production architectures
     
  
  
  10. New Application Models (e.g the symantic web, opensocial, widgets)
      


• Elaborate explanation of managing boilerplate text (e.g. titles, button labels, prompt, error messages, tool tips) in JSF applications. This includes more advanced locale requirements, like certain text that needs to be different when shown to junior and senior users.
  


• Here's a nice diagram with an overview of what activities are needed to create a website, from idea to support and everything in between.
  
  


• Always annoyed that you have to manually close a resource like InputStreams, Connections etc? And that the first exception might be surpressed by the second in the finally block? Here's a suggested solution: the Automatic Resource Management pattern by Joshua Bloch.
  


• Ten more Eclipse shortcuts you maybe didn't know...
  


• Of course you've heard/read that Microsoft has released IE8 last week. Here's a bunch of tips when migrating your site from IE7 to IE8.
  


• Ever need to create a UUID/GUID? Here's a few offline generators compared. uuidgen is an online UUID generator supporting version 1 and 4. A handy FAQ on UUIDs with some more depth can be found here.
  

Best of this Week Summary 02 March - 08 March 2009

• The UI teamlead of Google's Chrome browser explained at a presentation why they decided to build Chrome. Basically because all the existing browsers suck :-)
  


• A memory and performance comparison between Seam+JSF and Wicket. Wicket wins both. Also check the comments for useful feedback. Possible reasons for the differences in performance are: JSF performs much more expression evaluation and the JSF lifecycle is much more complex.
  


• The Open Group has released version 9 of The Open Group Architecture Framework (TOGAF) for enterprise architectures. TOGAF is often combined with ArchiMate for modelling. Most important addition to version 8 is the content framework which describes what an architecture exists of. Here's some feedback from actual users on TOGAF 9.
  


• Talking about standards, the OASIS committee has updated a bunch of webservices specifications/standards.
  


• A nice post on how to write a Javascript client that sites can use to access your REST API. Biggest challenges that had to be solved were:
  

  1. Browser same-origin restrictions on XMLHttpRequests (XHRs) and inter-window/frame access
     
  
  
  2. The lack of wide browser support for HTML 5-style message passing between windows.

• Java Enterprise Edition 6 (Java EE 6) Specification (JSR 316) is getting there...
  

Best of this Week Summary 8 December - 14 December 2008

• Spring's Web Flow 2 now lets you use JSF as view technology. It addresses a couple of the existing JSF issues and already some features only present in JSF 2.0.
  


• Microsoft (yes yes, don't stop reading immediately ;-) has published a How-To Design Using Agile Architecture guide which "will help you start the process of designing your application. It discusses the six main steps you should follow, and then discusses the issues involved in making logical choices. It also provides checklists to help you ensure that the proposed design will meet your requirements", including patterns, best practices and agile considerations. This is a quick summary of the guide.
  


• A tiny bit off-track, but still interesting to point out: of course you know Google's GWT, in which you can create a Javascript web front-end application in Java. But now this is also possible in Python (recently releasing version 3) with Pyamas! Pretty cool!
  


• Talking about software architecture, how would you document that correctly? Here's a bunch of good tips trying to answer that. It is a good high-level overview of what you should document in an application architecture. Focus is on UML 2.0, but what should be in the documentation is valid for any notation format.
  


• Here's the first list (and maybe last :-) I'll post on looking back @ 2008: on overview of what happened with Java in 2008.
  

JSFUnit static analysis unit testing in ADF

Introduction
Currently I'm working on the framework design of an ADF application in JDeveloper 11.1.1.0.0 (yes sometimes a man's got to do what a man's got to do ;-). One of the parts is how we are going to do (unit) testing. And one of elements in there is testing the JSF part of the ADF application. Application Developer Framework consists of several layers where the View layer consists of a JSF implementation. This JSF implementation is named ADF Faces (RichFaces) and built on top of Trinidad, the open source JSF components implementation. ADF Faces has many components Ajax-ized and has more components than Trinidad.
My eye caught JSFUnit, an open source project from JBoss. I was only able to focus on the static analysis part JSFUnit offers (it offers also other dynamic "regular unit" tests). But little information was found about that. I couldn't find any installation tips for ADF (JBoss here and here, and Websphere setup tips were available).
Thus it was just me and the computer. Here's the steps that in the end did do the job (running on Windows XP).

Setup
A couple of things are needed for all types of static analysis.

1. Download via JSFUnit Getting Started under the section “Files”: jboss-jsfunit-core-1.0.0.Beta3.jar en jboss-jsfunit-analysis-1.0.0.Beta3.jar
   


2. Note that it was not necessary to download/install myfaces-api-1.2.0.jar or JSF 1.2 API.
   


3. Start JDeveloper 11.1.1.0.0 and open an ADF application with Model and ViewController project.
   


4. Right-click the ViewController project, select Properties and select Libraries and Classpath in the popup. Add the above downloaded jars there.
   

Three types of static tests are possible with JSFUnit. I'll describe setting up each type seperately. Most information was deducted from this part of the JSFUnit documentation.

Configuration static analysis
These tests test your JSF configuration. See the above mentioned documentation part for examples of what tests are performed.

1. Create a JUnit testclass in your ViewController project. Modify it such that it matches this example class:
   
   

   package test.com.project; import java.io.File; import java.util.HashSet; import java.util.Set; import org.jboss.jsfunit.analysis.AbstractFacesConfigTestCase; public class JSFUnitStaticAnalysisConfigTest extends AbstractFacesConfigTestCase { private static Set paths = new HashSet() {{ // Example absolute path: add("C:/work/workspace/jsf-unit/src/faces-config.xml"); // Relative path example below. add("public_html\\WEB-INF\\faces-config.xml"); }}; public JSFUnitStaticAnalysisConfigTest() { super(paths); } }

   
   
   Note the paths variable which points to the faces-config file to validate. Relative paths work too. Of course might not be valid in your test/production environment.
   
   Tip: notice for easier separation at deployment, I put the test class in a separate package, starting with "test.".
   


2. And you're set: run the test. Of course you should see a green bar. If not, your config is probably not 100% ok (probably because what if a JSFUnit test is incorrect... Of course you then immediately contribute to the JSFUnit community project :-). I had for example several Serialization errors.
   
   Below is a screenshot with the result of running the config testcase:
   
   
   

TLD analysis
These tests test your TLDs. See the above mentioned documentation part for examples of what tests are performed.

1. Add the dependent libraries mentioned here, at the bottom of the page: maven-taglib and commons-logging. For the commons-logging you can use the one provided by JDeveloper: Commons Logging 1.0.4. The third one, jsp-api-2.1.jar does not seem to be necessary in the ADF project.
   


2. Create a JUnit testclass in the ViewController project with .tld files. Modify it such that it matches this example class:
   
   

   package test.com.project; import java.util.HashSet; import java.util.Set; import org.jboss.jsfunit.analysis.AbstractTldTestCase; import static org.junit.Assert.*; public class JSFUnitStaticAnalysisTLDTest extends AbstractTldTestCase { private static Set paths = new HashSet() {{ // Example: add("C:/work/workspace/jsf-unit/src/demo.tld"); add("C:\\myprojects\\app\\src\\META-INF\\myjsf.tld"); }}; public JSFUnitStaticAnalysisTLDTest() { super(paths); } }

   
   
   Note the paths variable which points to the .tld to validate. Did not try if a relative path also works.
   


3. And you're set: run the test. Of course you should see a green bar. If not, your .tld is probably not 100% ok.
   
   Below is a screenshot with the result of running the TLD testcase:
   
   
   

View static analysis
These tests test your JSF views. See the above mentioned documentation part for examples of what tests are performed.

1. No extra libs are needed, so we can immediately create a JUnit testclass in the ViewController project. Modify it such that it matches this example class:
   
   

   package test.com.project; import java.io.File; import java.util.HashSet; import java.util.Set; import org.jboss.jsfunit.analysis.AbstractFacesConfigTestCase; import org.jboss.jsfunit.analysis.AbstractViewTestCase; public class JSFUnitStaticAnalysisViewTest extends AbstractViewTestCase { private static Set absoluteViewPaths = new HashSet() {{ // Example: add("C:/work/project/src/home.xhtml"); add("C:\\myprojects\\app\\mysite\\ViewController\\public_html\\detailsPage.jspx"); }}; private static Set recursiveViewPaths = new HashSet() {{ // Example: add("C:/work/project/src/views"); add("C:\\myprojects\\app\\mysite\\ViewController\\public_html"); }}; public JSFUnitStaticAnalysisViewTest() { super(absoluteViewPaths, recursiveViewPaths, "public_html\\WEB-INF\\faces-config.xml"); } }

   
   
   Note the paths variables. Nowhere I could find what they exactly mean. The above runs a test that passes, so I assume the paths are set correctly...
   


2. And you're set: run the test. Of course you should see a green bar. If not, your view is probably not 100% ok.
   
   Below is a screenshot with the result of running the view testcase:
   
   

Conclusion
So that's it. Not hard at all! If you want to know a bit more high level stuff about JSFUnit, check this presentation by the project lead at the Javapolis conference (currently rebranded to Devox conference). And here's another introduction presentation.

The Shale Test Framework could be an interesting alternative for unittesting JSF. Needs some more investigation...

Best of this Week Summary 29 September - 05 October 2008

• Check the elaborate 95 slides comparison of Javascript libraries at the bottom of this post. It's a presentation by John Resig, Mr JQuery. The presentation is very objective. Compared are: Prototype, jQuery, Yahoo UI, Dojo and Mootools. Another short comparison of 14 RIA/Ajax/Javascript frameworks shows jQuery as the winner, as seen by the User eXperience reviewer. Great news for jQuery this week anyway: both Nokia and Microsoft are adopting it as part of their official application development platform.
  


• Can't get enough of these RIA frameworks comparisons? Here's another one, which is a short comparison/intro of three Rich Internet Application frameworks: Adobe AIR, Google Gears and Silverlight. See also my (bit older) post here, which also includes JavaFX.
  


• Summary of an article by Martin Fowler on how Agile can be used in building SOA implementations. The answer: yes you can quickly get value out of it. The biggest proof is the internet: loosely coupled and many unexpected changes.
  


• Quick-start JSF book free for download. Only 65 pages. Beginners level, step-by-step. With some mixed "infomercials" about the soon to be open source Eclipse IDE extension Exadel Studio Pro, but not in an annoying way.
  


• Key API design points from Joshua Bloch, Chief Java Architect at Google
  


• An explanation why a canonical message model (CMM) is a "good thing" in SOA and ESB.
  


• How to manage and lead geeks in a team. For technical and non-technical teamleaders.
  

Best of this Week Summary 22 September - 28 September 2008

• 10 aspects of web 2.0 strategies that a CTO and CIO should know about.
  


• AJAX security fundamentals. With XSS, CSRF and securing JSON.
  


• Recently started foundation by Tim Berners-Lee (inventor of the web). Its goal is to study the web and how to make it more accessible.
  


• Short overview of forms of API authentication: keys, username/password, digest and tokens. I'm missing oAuth in the examples mentioned.
  


• From March 2008: short overview of the status of web frameworks and their marketshare: Spring MVC, GWT, Struts 2, JSF, Flex, OpenLaszlo. Also mentions AppFuse as starting point for building a web application.
  


• One of many architecture and design diagrams for an application built on Struts2, Spring, Hibernate and ExtJS. Could be a good starting/reference point.
  

Best of this Week Summary 24 February - 02 March 2008

• Great set of JSF pitfalls and anti-patterns.
  


• Nice article explaining Web Oriented Architecture and its basics. Might it be the future of SOA? The differences between SOA and WOA are also described.
  


• A quite old article on using XSDs effectively in WSDL design, but still seems valid.
  


• Nice simple Java Persistence API (JPA) implementation for Amazon's SimpleDB.
  

Best of this Week Summary 14 January - 20 January 2008

• Benchmark test of the Javascript performance of Opera, Safari, Explorer and Firefox. Firefox 3b2 vs Ffox 2 seems to head in the right direction too (i.e, 3 getting better and better).
  


• Article that discusses the AjaxComponent strategy to introduce Ajax into your JSF application, including a step-by-step example which uses MyFaces 1.1.5 and the Dojo. If you would handle an Ajax request via a standard JSF component method or using a phase listener, it would give you not enough control or you'd break encapsulation. Combining these two approaches you get what you want (and need): input/output logic nicely packaged in the renderer! There's also mention of a related pattern introduced by the writer: the JSF AjaxCommand strategy, which you would use if the functionality you're providing is only required by one component.
  


• An automated solution on how to implement Yahoo's Rule #3 from YSlow: setting the Expires header on your static data (images, css, javascript etc). Not obvious since it means dynamically incorporating the version nr in your CSS, javascript files for example.
  


• BIG news was of course this week the two large acquisitions: Sun buying MySQL and Oracle buying BEA Systems.
  Gigaspaces is expecting Oracle to either discontinue WebLogic or continue with little innovation. Rod Johnson from SpringSource (formerly Interface 21) is expecting (hoping?) quite the opposite: Oracle will discontinue their OC4J application server, because of WebLogic's market position. Here's some more considerations. My expection is a merge of the best of the two products. Only time will tell...
  


• Great news was of course that Yahoo! is now allowing all users to OpenID-enable their user account. It adds a total of potentially 250M new OpenID users. I still doubt it will be enough to get OpenID widely accepted, most of the points I mentioned here still apply; just allowing more users to use an OpenID is not taking these away.