The Validator Framework The Validator Framework Chuck Cavaness - - PowerPoint PPT Presentation

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The Validator Framework The Validator Framework Chuck Cavaness - - PowerPoint PPT Presentation

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The Validator Framework The Validator Framework Chuck Cavaness Chuck Cavaness Chuck Cavaness Introduction Introduction Senior Technologist (S1 Corporation) Senior Technologist (S1 Corporation) Co Co- -Author of Special

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SLIDE 1

The Validator Framework The Validator Framework

Chuck Cavaness Chuck Cavaness Chuck Cavaness

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SLIDE 2

Introduction Introduction

  • Senior Technologist (S1 Corporation)

Senior Technologist (S1 Corporation)

  • Co

Co-

  • Author of Special Edition EJB 2.0 and Special

Author of Special Edition EJB 2.0 and Special Edition Java 2 Edition Java 2

  • Author of Jakarta Struts from O’Reilly and Struts

Author of Jakarta Struts from O’Reilly and Struts Pocket Reference Pocket Reference

  • Various Articles for O’Reilly, Linux Magazine,

Various Articles for O’Reilly, Linux Magazine, JavaWorld, etc. JavaWorld, etc.

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SLIDE 3

Agenda Agenda

  • The Need for Validation

The Need for Validation

  • Basic Validation Concepts

Basic Validation Concepts

  • Introduce the Validator Framework

Introduce the Validator Framework

  • Validator with/without Struts

Validator with/without Struts

  • Discuss Validator Best Practices

Discuss Validator Best Practices

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SLIDE 4

What’s the Big Deal? What’s the Big Deal?

! ! Lexical Validation

Lexical Validation

! ! Syntactic Validation

Syntactic Validation

! ! Semantic Validation

Semantic Validation

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SLIDE 5

Lexical Validation Lexical Validation

  • Is the single value “well

Is the single value “well-

  • formed”?

formed”?

  • The Structure of the data is correct

The Structure of the data is correct

  • But nothing can be said of the content

But nothing can be said of the content

  • Can typically be done on the client or server

Can typically be done on the client or server

  • E.g. Did the user enter an integer for an age

E.g. Did the user enter an integer for an age field? field?

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SLIDE 6

Syntactic Validation Syntactic Validation

  • Well

Well-

  • formed, but does the data follow

formed, but does the data follow the proper syntax the proper syntax

  • Can typically be done on client, but must

Can typically be done on client, but must watch out for I18N issues watch out for I18N issues

  • E.g < day> /< month> /< year>

E.g < day> /< month> /< year>

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SLIDE 7

Semantic Validation Semantic Validation

  • Does the data make sense for your

Does the data make sense for your domain domain

  • Should be done on server

Should be done on server

  • E.g. You asked for a future ship date, but

E.g. You asked for a future ship date, but the user entered a date in the past the user entered a date in the past

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SLIDE 8

The Need for Validation The Need for Validation

Enterprise Data

J2 EE Cluster

W AP Server Web Server/ Servlet Container Cluster AS4 0 0 Business Partners SOAP/ XML Web Services JDBC RMI/ IIOP RMI/ IIOP Internal Applications JDBC Native Batch

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SLIDE 9

Where does the Validation Where does the Validation Live? Live?

  • Business Logic Validation

Business Logic Validation

  • Presentation Validation

Presentation Validation

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SLIDE 10

Presentation vs. Business Logic Presentation vs. Business Logic

Enterprise Data Web Server/ Servlet Container J2 EE Server HttpRequest HttpResponse HttpRequest EJB I nvocation SQL Query

Authenticate( )

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SLIDE 11

Validation without the Validation without the Validator Validator

  • public ActionErrors validate(ActionMapping mapping, HttpServlet

public ActionErrors validate(ActionMapping mapping, HttpServletRequest request) { Request request) {

  • ActionErrors errors = new ActionErrors();

ActionErrors errors = new ActionErrors();

  • / / Get access to the message resources for this application

/ / Get access to the message resources for this application

  • / / There's not an easy way to access the resources from an A

/ / There's not an easy way to access the resources from an ActionForm ctionForm

  • MessageResources resources =

MessageResources resources =

  • (MessageResources)request.getAttribute( Globals.MESSAGES_K

(MessageResources)request.getAttribute( Globals.MESSAGES_KEY ); EY );

  • / / Validate that the usernam e entered was not null

/ / Validate that the usernam e entered was not null

  • if(getUsernam e() = = null | | getUsernam e().length() < 1) {

if(getUsernam e() = = null | | getUsernam e().length() < 1) {

  • String usernam eLabel = resources.getMessage( "label.usernam e

String usernam eLabel = resources.getMessage( "label.usernam e" ); " );

  • errors.add( ActionErrors.GLOBAL_ERROR,

errors.add( ActionErrors.GLOBAL_ERROR,

  • new ActionError("errors.required", usernam eLab

new ActionError("errors.required", usernam eLabel )); el ));

  • }

}

  • / / Validate that the password entered was not null

/ / Validate that the password entered was not null

  • if(getPassword() = = null | | getPassword().length() < 1) {

if(getPassword() = = null | | getPassword().length() < 1) {

  • String passwordLabel = resources.getMessage( "label.password

String passwordLabel = resources.getMessage( "label.password" ); " );

  • errors.add( ActionErrors.GLOBAL_ERROR,

errors.add( ActionErrors.GLOBAL_ERROR,

  • new ActionError("errors.required", passwordLab

new ActionError("errors.required", passwordLabel )); el ));

  • }

}

  • return errors;

return errors;

  • }

}

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SLIDE 12

Order Form Order Form Order Form

Extrapolating this Approach to Validating Extrapolating this Approach to Validating

Username and Password Account Number, Email, Contact Information, etc. Credit Card, Quantity, Shipping Address, etc. Logon Form Logon Form Order Form Order Form Order Form Customer Form

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SLIDE 13

The Validator Framework The Validator Framework

  • Open source Validation framework

Open source Validation framework

  • Developed by David Winterfeldt

Developed by David Winterfeldt

  • Integrated into Struts core during 1.1

Integrated into Struts core during 1.1

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SLIDE 14

Features of the Validator Features of the Validator

  • Supports Client

Supports Client-

  • Side (JavaScript) and Server

Side (JavaScript) and Server-

  • Side (Java) validation

Side (Java) validation

  • Comes with many pre

Comes with many pre-

  • built validation routines

built validation routines

  • Allows for regular expressions to be used

Allows for regular expressions to be used

  • Can be used with or without Struts

Can be used with or without Struts

  • Pluggable Validators

Pluggable Validators

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SLIDE 15

Validator Rules Repository Application Validator Mappings

Validator Framework

Architecture of the Validator Architecture of the Validator

Struts Framework Application Framework

Action Form s Request Processor Actions Validators Plugin Validator Action Form s

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SLIDE 16

Validator Sequence Diagram Validator Sequence Diagram

Login Form ActionServlet doPost RequestProcessor {login.do was sent in request} process() processValidate() ActionForm validate() Validator validate()

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SLIDE 17

Basic Validation Rules Basic Validation Rules

  • Required

Required

  • Mask

Mask

  • Range(

Range(intRange,

intRange, floatRange floatRange)

)

  • MaxLength

MaxLength

  • MinLength

MinLength

  • Date

Date

  • Credit Card

Credit Card

  • Email

Email

  • Byte,short,Integer

Byte,short,Integer

  • Long,Double,Float

Long,Double,Float

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SLIDE 18

Using the Validator with Using the Validator with Struts Struts

1.

  • 1. Add the Validator Plugin

Add the Validator Plugin 2.

  • 2. Configure the Validation.xml File

Configure the Validation.xml File 3.

  • 3. Extend the Validator ActionForms or use

Extend the Validator ActionForms or use Dynamic ActionForms Dynamic ActionForms 4.

  • 4. Set validate= “true” on Action Mappings

Set validate= “true” on Action Mappings

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SLIDE 19

Adding Validator Plugin Adding Validator Plugin

<plug-in className="org.apache.struts.validator.ValidatorPlugIn"> <set-property property="pathnames" value="/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml"/> </plug-in>

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SLIDE 20

Validator Configuration Files Validator Configuration Files

  • validator

validator-

  • rules.xml

rules.xml

  • validation.xml

validation.xml

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SLIDE 21

The Rules Configuration File The Rules Configuration File

<validator name="required" classname="org.apache.struts.util.StrutsValidator" method="validateRequired" methodParams="java.lang.Object,

  • rg.apache.commons.validator.ValidatorAction,
  • rg.apache.commons.validator.Field,
  • rg.apache.struts.action.ActionErrors,

javax.servlet.http.HttpServletRequest" msg="errors.required"> //…some text deleted

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SLIDE 22

Validation Configuration File Validation Configuration File

… < form name= “loginForm "> < field property= “em ail" depends= "required"> < arg0 key= “label.em ail"/ > < / field> < field property= “passw ord" depends= "required"> < arg0 key= “label.passw ord"/ > < / field> < / form> …

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SLIDE 23

Resource Bundle Resource Bundle

… errors.required= { 0 } is required. errors.minlength= { 0} can not be less than { 1} characters. errors.maxlength= { 0} can not be greater than { 1} characters. errors.invalid= { 0} is invalid. errors.byte= { 0} must be an byte. errors.short= { 0} must be an short. errors.integer= { 0} must be an integer. errors.long= { 0} must be an long. errors.float= { 0} must be an float. errors.double= { 0} must be an double. errors.date= { 0} is not a date. …

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SLIDE 24

ActionForms and the Validator ActionForms and the Validator

  • Standard ActionForms

Standard ActionForms

– – ValidatorActionForm ValidatorActionForm – – ValidatorForm ValidatorForm

  • Dynamic ActionForms

Dynamic ActionForms

– – DynaValidatorActionForm DynaValidatorActionForm – – DynaValidatorForm DynaValidatorForm

Validator supports both types of ActionForms:

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SLIDE 25

ActionForm Hierarchy ActionForm Hierarchy

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SLIDE 26

A Validator Example! A Validator Example!

Let’s step through an example.

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SLIDE 27

Using JavaScript with the Validator Using JavaScript with the Validator

< javascript> < ![ CDATA[ function validateMinLength(form) { var isValid = true; var focusField = null; var i = 0; var fields = new Array();

  • MinLength = new minlength();

for (x in oMinLength) { var field = form[ oMinLength[ x] [ 0] ] ; if (field.type = = 'text' | | field.type = = 'textarea') { var iMin = parseI nt(oMinLength[ x] [ 2] ("minlength")); if ((field.value.length > 0) && (field.value.length < iMin)) { if (i = = 0) { focusField = field; } fields[ i+ + ] = oMinLength[ x] [ 1] ; isValid = false; } } } if (fields.length > 0) { focusField.focus(); alert(fields.join('\ n')); } return isValid; } ] ] > < / javascript>

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SLIDE 28

Using JavaScript with the Validator Using JavaScript with the Validator

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I18N and the Validator I18N and the Validator

  • Validator framework uses the Struts

Validator framework uses the Struts resource bundle resource bundle

  • The < formset> element supports

The < formset> element supports language, country and variant language, country and variant

< formset> … < / formset> < formset language= "fr"> … < / formset> < formset language= "fr" country= "CA"> … < / formset>

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SLIDE 30

Validator Advanced Topics Validator Advanced Topics

  • Creating Custom Validators

Creating Custom Validators

  • Using Programmatic Validation along with

Using Programmatic Validation along with the Validator the Validator

  • Validating Dependent Fields

Validating Dependent Fields

  • Using the Validator outside of Struts

Using the Validator outside of Struts

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SLIDE 31

Creating Custom Validation Creating Custom Validation Rules Rules

1.

  • 1. Create the new validation method.

Create the new validation method. 2.

  • 2. Modify the validation

Modify the validation-

  • rules.xml file to

rules.xml file to contain the new validation method. contain the new validation method. 3.

  • 3. Modify the validation.xml file to use the

Modify the validation.xml file to use the new validation rule. new validation rule.

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SLIDE 32

Creating the Custom Method Creating the Custom Method

public static boolean validateExactLength(Object bean, ValidatorAction va, Field field, ActionErrors errors, HttpServletRequest request) { String value = null; if (isString(bean)) { value = (String) bean; } else { value = ValidatorUtil.getValueAsString(bean, field.getProperty()); } String exactLength = field.getVarValue("exactlength"); if (!GenericValidator.isBlankOrNull(value)) { try { int length = Integer.parseInt(exactLength); if ( value.length() != length ) { errors.add(field.getKey(), Resources.getActionError(request, va, field)); return false; } } catch (Exception e) { errors.add(field.getKey(), Resources.getActionError(request, va, field)); return false; } } return true; }

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SLIDE 33

Updating validator Updating validator-

  • rules.xml

rules.xml

< validator name= "exactLength" classname= "MyValidator" method= "validateExactLength" methodParams= "java.lang.Object,

  • rg.apache.commons.validator.ValidatorAction,
  • rg.apache.commons.validator.Field,
  • rg.apache.struts.action.ActionErrors,

javax.servlet.http.HttpServletRequest“ depends= “required” m sg= "errors.exactlength"> < / validator>

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SLIDE 34

Declaring the New Rule Declaring the New Rule

… < form name= "checkoutForm"> < field property= "shippingAddress" depends= "exactLength"> < arg0 key= "label.address"/ > < arg1 name= "exactLength" key= "$ { var:exactlength} " resource= "false"/ > < var> < var-nam e> exactlength< / var-nam e> < var-value> 1 0 < / var-value> < / var> < / field> < field property= "shippingCity" depends= "required,mask"> < arg0 key= "label.city"/ > < var> < var-name> mask< / var-name> < var-value> ^ [ a-zA-Z] * $< / var-value> < / var> < / field> …

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SLIDE 35

Executing the Executing the ExactLength ExactLength Rule Rule

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Using Programmatic and Declarative Using Programmatic and Declarative Validator Validator

It’s possible to use manual validation along It’s possible to use manual validation along with the Validator framework. with the Validator framework.

public class LoginForm extends ValidatorActionForm { public ActionErrors validate(ActionMapping mapping, HttpServletRequest request) { / / Call the super validate so the Validator framework can do its thing! ActionErrors errors = super.validate( mapping, request ); / / Do some special customized validation stuff here / / In the end, return any and all ActionErrors return errors; } }

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SLIDE 37

Validating Dependent Fields Validating Dependent Fields

  • Currently done using the

Currently done using the RequiredIf RequiredIf Rule Rule

  • In a future release (after 1.1 GA), the

In a future release (after 1.1 GA), the validwhen validwhen Rule should be used. Rule should be used.

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SLIDE 38

Using the Validator outside of Using the Validator outside of Struts Struts

  • Can be used to provide validation on any

Can be used to provide validation on any JavaBean JavaBean

  • Package Dependencies include:

Package Dependencies include:

– – ORO ORO – – Commons Logging, Commons Logging, BeanUtils BeanUtils, Collections, , Collections, Digester Digester – – XML Parser XML Parser

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SLIDE 39

Using the Validator outside of Using the Validator outside of Struts (cont) Struts (cont)

  • Some upfront work is necessary

Some upfront work is necessary

  • Method signatures must be changed in

Method signatures must be changed in validation validation-

  • rules.xml

rules.xml

  • The same validation.xml file can be used

The same validation.xml file can be used

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SLIDE 40

Resources Resources

  • Validator Home

Validator Home -

  • http://

http:// jakarta jakarta.apache.org/commons/validator/index.html .apache.org/commons/validator/index.html

  • An O’Reilly Article by Chuck Cavaness

An O’Reilly Article by Chuck Cavaness -

  • http://www.onjava.com/pub/a/onjava/2002/12/11/jakartastruts.html

http://www.onjava.com/pub/a/onjava/2002/12/11/jakartastruts.html

  • Home of the Validator Creator

Home of the Validator Creator – – http://home.earthlink.net/~ http://home.earthlink.net/~ dwinterfeldt dwinterfeldt

  • Struts User Guide Info

Struts User Guide Info -

  • http://

http:// jakarta jakarta.apache.org/struts/ .apache.org/struts/ userGuide userGuide/dev_validator.html /dev_validator.html

  • Browsing the Struts List

Browsing the Struts List -

  • http://marc.theaimsgroup.com

http://marc.theaimsgroup.com or

  • r

http:// http:// nagoya nagoya.apache.org/ .apache.org/ eyebrowse eyebrowse

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SLIDE 41

Q & A Q & A

What did I miss?