Your SlideShare is downloading. ×
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Declarative Input Validation with JSR 303 and ExtVal
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×
Saving this for later? Get the SlideShare app to save on your phone or tablet. Read anywhere, anytime – even offline.
Text the download link to your phone
Standard text messaging rates apply

Declarative Input Validation with JSR 303 and ExtVal

1,497

Published on

Slides of my talk at the CONFESS_2011 conference in Vienna, Austria

Slides of my talk at the CONFESS_2011 conference in Vienna, Austria

Published in: Technology
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
1,497
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
6
Comments
0
Likes
0
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Declarative input validationwith JSR 303 and ExtValApril 13th, 2011 – Bart Kummel
  • 2. Who am I?● Bart Kummel● 10 years experience in software development ● Of which 6 years in Java EE● Consultant @ Transfer Solutions, Leerdam, NL● Competence manager @ Transfer Solutions, Leerdam, NL● Author of Apache MyFaces 1.2 Web Application Development ● See http://tinyurl.com/am12wad 2
  • 3. Photo: Salar de Uyuni, Bolivia; © 2010 by Bart Kummel 3
  • 4. Don’t Repeat Yourself● Less code = less bugs● Duplicated code = duplicated bugs● Duplicated code = duplicated maintenance● Dupliacted maintenance = forgotten maintenance 4
  • 5. DRY violations in classic Java EE apps● Validation is programmed in Model beans ● Because that’s where it belongs● Validation is repeated in View layer ● Because you have to use JSF Validators● Validation is even repeated multiple times in the View ● Because the same bean is used in multiple JSF pages 5
  • 6. Let’s fix this● Remove validation code from View● Let View generate validation based on ModelHow to fix it?● That’s why Bean Validation (JSR 303) was created 6
  • 7. JSR 303: the idea● Standardized way to express validation constraints● Any UI technology can interpret those constraints and enforce them● Non-UI technologies can also use the validation information 7
  • 8. JSR 303: the idea implemented● JSR 303 is part of Java EE 6● The reference implementation is Hibernate Validator 4.* ● See http://hibernate.org/subprojects/validator.html ● Hibernate Validator 4.* can also be used in Java EE 5● A JSR 303 implementation is only the way to express the validation constraints ● You don’t get UI validation logic if the UI framework doesn’t support JSR 303 8
  • 9. How to add Bean Validation to a Java EE 5 application● Add Hibernate Validator 4.* as library ● ...and some extra libraries, provided in the Hibernate Validator package● Use JSR 303 annotations in your beans● Use MyFaces ExtVal 1.2.* to add declarative validation support to JSF 1.2 9
  • 10. Bean Validation in Java EE 6● No need to add a JSR 303 implementation ● JSR 303 is part of the Java EE 6 platform● Use JSR 303 annotations in your beans● JSF 2.0 has support for JSR 303 annotations out of the box ● But support is limited● You can (and should!) still use ExtVal (2.0.*) and get lots of benefits (more on that later) 10
  • 11. Side note: ExtVal versioning● There are three current versions of ExtVal ● 1.1.* for JSF 1.1 ● 1.2.* for JSF 1.2 ● 2.0.* for JSF 2.0● The latest stable release is release 3 ● That is: 1.1.3, 1.2.3 and 2.0.3● Lots of exciting new stuff is going into the next version ● Snapshot releases of ExtVal are very high quality 11
  • 12. Example: classic validation code in beanprivate int capacity;public void setCapacity(int capacity) { if(capacity >= 0 && capacity <= 100000) { this.capacity = capacity; } else { // throw exception }} 12
  • 13. Example: JSR 303 annotations@Min(0)@Max(100000)private int capacity;public void setCapacity(int capacity) { this.capacity = capacity;} enefits: Extra b – less code eadable – better r 13
  • 14. Example: classic validation in JSF page<h:inputText value="#{room.capacity}" > <f:validateLongRange minimum = "0" maximum = "100000" /></h:inputText> 14
  • 15. Example: no validation in JSF page!<h:inputText value="#{room.capacity}" /> 15
  • 16. Demo 1:Bean Validation basics in Java EE 6
  • 17. So why do we need ExtVal?● To use Bean Validation in Java EE 5 / JSF 1.2● To have advanced options in Java EE 6 17
  • 18. ExtVal on Java EE 6: advanced options● Cross validation● Violation severity ● i.o.w. give warnings instead of errors● More flexibility in choice of annotations to use ● JSR 303, JPA, ExtVal, own annotation or any combination● Customization on all levels, e.g.: ● Custom message resolvers ● Custom validation strategies demos Custom meta data coming ● up! 18
  • 19. Configuring ExtVal● Just add the ExtVal .jar files to your project 19
  • 20. Demo 2:Adding the ExtVal .jar files to our project
  • 21. Cross validation● Examples of cross validation ● check if two values are equal ● check if date is before or after other date ● value is only required if other value is empty (or not) ● etcetera... 21
  • 22. Demo 3:Cross validation
  • 23. Demo 3 – Summary● @DateIs can be used for date-related cross validations ● Use DateIsType.before, DateIsType.after or DateIsType.same● Other cross validation annotations: ● @Equals and @NotEquals for equality-based cross validation of any type ● @RequiredIf for conditional required fields – Use RequiredIfType.empty or RequiredIfType.not_empty 23
  • 24. Violation severity● Give certain validation rules a severity level of “warning”● A warning will be given to the user, but “invalid” data can be submitted 24
  • 25. Demo 4:Setting violation severity to “warning”
  • 26. Demo 4 – summary● Violation severity is not part of the JSR 303 standard ● We use payload to add violation severity level as custom meta data● JPA also interprets JSR 303 contraints before persisting data, but does not recognise violation severity ● Solution: use ExtVal annotations instead 26
  • 27. Customization on all levels ● ExtVal is full of customization hooks ● A lot of ready-made add-ons are available ● see http://os890.blogspot.com 27
  • 28. Demo 5:Creating a custom annotation and acustom validation strategy
  • 29. Demo 5 – summary● Technically, creating a custom annotation is not an ExtVal feature ● It is just a Java feature● We need an ExtVal validation strategy to make a custom annotation work● We need to map our annotation to our validation strategy ● We can create a startup listener for this ● As an alternative we can use ExtVal plugins to use alternative ways of configuration 29
  • 30. Summary● With annotation based validation, we can finally create DRY JSF applications● ExtVal gives us the opportunity to use annotation-based validation on Java EE 5● On Java EE 6, ExtVal gives us: ● More powerful annotation-based validation ● More flexibility 30
  • 31. More info...● Workshop tomorrow: ‘Rule your model with Bean-Validation’ ● 08:00 – 10:00, Room 2 – Gerhard Petracek● I will put links to slides & demo code on my blog ● http://www.bartkummel.net● Chapter 10 of MyFaces 1.2 Web Application Development ● http://tinyurl.com/am12wad● MyFaces ExtVal: ● http://myfaces.apache.org/extensions/validator ● http://os890.blogspot.com/ 31
  • 32. Questions & answers A wise man can learn more from a foolish question than a fool can learn from a wise answer. Bruce Lee 32

×