wste struts presenation 10-18-07

8/21/2019 WSTE Struts Presenation 10-18-07

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WebSphereSupport Technical Exchange

Introduction to the Struts Framework withWebSphereCommerce

Meng Fu, Mike Callaghan, Polina Gohshtein


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WebSphereSupport Technical Exchange 2

Agenda

Introduction to Struts

Struts Framework

Mapping URLs and Views

Customization Points

Common Pitfalls

Questions and Answers


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What Is Struts?

Struts framework was designed to help develop web

applications that utilize an MVC architecture

Separate display logic from business logic using MVC

Model = business logic (data model)

View = presentationController = navigational code between model and view

Three key components to the Struts framework:

A "request" handler

A "response" handler

A tag library


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How Commerce Uses Struts?

Supports the use of Struts 1.1

Uses Struts for routing requests

Extends the following struts components:

org.apache.struts.action.ActionServlet

org.apache.struts.action.Action

org.apache.struts.action.ActionMapping

Uses the following struts component:org.apache.struts.action.RequestProcessor


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Struts Framework: Action Servlet

Receives an HTTP request

Uses Struts configurationfiles to determine theappropriate applicationmodule

Routes the request to themodule's request processor

ECActionServlet is theCommerce extension of theStruts ActionServlet class


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Struts Framework: Request Processor

Determines the action

mapping and action formassociated with a request

Populates and validates theaction form

Passes the request, actionform, and action mapping tothe BaseAction

Forwards the user to theappropriate view when theaction is complete


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Struts Framework: Base Action

Bridges an incoming

request to thecorresponding businesslogic

Uses the configuration in

the action mapping todetermine the command toinvoke

BaseAction is the

Commerce extension of theStruts Action class


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Struts Framework: Business Logic Faade

Maps interface name to

implementation

Queries the CMDREG todetermine the appropriateimplementation

Invokes the appropriatecontroller command


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Struts Framework: Action Mapping

Maps a request to a

command interface or aview

Includes Commerce specificproperties such as https,

authenticate, andcredentialsAccepted

ECActionMapping is theCommerce extension of the

Struts ActionMapping class


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Struts Framework: Global Forward

Maps a request to a JSP

Includes Commerce specificproperty resourceClassNameindicating a redirect orforward

ECActionForward is theCommerce extension of theStruts ActionForward class


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Mapping URLs to Controller Commands

Action mappings


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Mapping Views to JSPs

Action mappings and global forwards


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Mapping Messaging Views

Global forwards


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Customization Points

ServletFilter

ECActionServlet

RequestProcessor

BaseAction

1 23

1 Servlet Filters (such as Runtime Filter and Cache Filter)add processing for all requests

2 Adds processing for non-cached requests

3 Adds processing for selective commands

Web Container


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Customization: Servlet Filters

Servlet filters allow you to intercept the request when it first

enters and before it leaves the Web Container

Use a servlet filter to perform pre- and post-processingactions on the incoming request or outgoing response objects

The following servlet filters are provided with WebSphereCommerce:

RuntimeServletFilter

CacheFilter


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Customization: Servlet Filters

Typical applications of servlet filters:

Logging and auditing track users and their behaviorusing a web application

Authentication block requests based on user identity

Localization target the request and response to aparticular locale

XML conversion render an XML document to HTMLprior to returning to the caller


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Customization: Request Processor

The request processor allows you to execute some business

logic before an action is executed

Request processor has access to the Struts config data

Request processor only processes non-cached requests

TilesRequestProcessor:

Extends the Struts RequestProcessor to handle tilesrequests

Delegates non-tiles requests to the baseRequestProcessor class


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Customization: Request Processor

To customize the request processor:

Extend the RequestProcessor or theTilesRequestProcessor

Set the value of the processor class property in struts-

config-ext.xml to your custom class:

An example customization of the request processor is to forcea secured request into a non-secured request


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Customization: Base Action

Last point in the request processing before the request is

handed over to the controller command

WebSphere Commerce provides two extensions of the StrutsAction class

BaseActionAjaxAction - used for AJAX style requests

Customize the BaseAction or the AjaxAction classes, if you

need to execute some business logic for a specific group ofcommands


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Customization: Base Action

To customize the base Action:

Create a custom class extending BaseAction/AjaxActionand add functionality to the preProcess and thepostProcess methods

Update the action mapping with the new class

The Extending a Struts action tutorial provides an exampleof how to customize the BaseAction class in order to trackthe referral URL


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Customization: Struts Validator

Removes extensive parameter checking from the commands

Makes use of ActionForms

To use the Struts Validator:

Add the Validator plug-in to the struts-config-ext.xml:

Configure your action to use validation:


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Customization: Struts Validator

Define rules in validation.xml:

Define message resources in struts-config-ext.xml:

Define messages in storeErrorMessages properties:


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Customization: Tiles

Separate content from layout, reduce redundancy

Alternative to the JSP include mechanism

Tiles is a template-based, Struts custom tag library

To enable the use of Tiles:Add the Tiles plug-in to the struts-config-ext.xml:

Define the tiles tag library at the top of a JSP:


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Customization: Tiles

tiles-defs.xml

struts-config-ext.xml


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Common Pitfalls: Tiles definition

Problem:

Added tiles support to struts-config.xml, and definitionsin tiles-defs.xml, and although tiles plugin is loaded,the tiles themselves are not processed

Cause:

ECActionServlet changes the base implementation oftiles in struts

Solution:

The store identifier must be prepended to the storeidentifier name.


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Common Pitfalls: struts-config XMLs

Problem:

You have custom struts definitions but are not surewhere to put them

Solution:

Order of loading for struts config files is in the web.xml

of the module:

The last configuration loaded is the one used

com.ibm.commerce.struts.ECActionServletconfig/WEB-INF/struts-config.xml,/WEB-INF/struts-config-migrate.xml,/WEB-INF/struts-config-ext.xml


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Common Pitfalls: Scheduler/Messaging

Problem:

Custom action mapping is not found by a scheduler ormessaging command

The original action mapping is used instead

Cause:

Request from Web channel is evaluated differently thanone invoked by messaging or the scheduler

Configuration is read in order the web modules areloaded, which may not be consistent

Solution:

Remove duplicate mappings in all other modules

Or apply APAR LI72530


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Common Pitfalls: URL forced to https

Problem:

Every time a particular view is executed, it forces theURL to HTTPS, but you want it to be accessedthrough HTTP

Cause:

The view is only defined with https enabled for thatstoreId, or only a site definition with https enabled

Solution:

Explicitly set the https property to 0 for the storeId:


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Common Pitfalls: Adding Authentication

Problem:

Views with the 'authenticate flag set to true do notrender correctly, result in Generic Error page

Cause:

Guest user hits a page that requires authentication,

CatalogDataBean fails on LogonForm pageRuntime authentication redirects the user to LogonForm

URL using only the storeId and URL parameter, missingdue to missing catalog_id parameter

Solution:Modify the LogonForm JSP so that when authenticated

feature is used, it retrieves catalogId from the next URLrather than request properties


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Common Pitfalls: Partial Credentials

Problem:

With persistent sessions, a user who is partiallyauthenticated (or Remembered) cannot accessrestricted views

Cause:

The default credentials accepted for a view is set to R,partially authenticated

Solution:

Update the credentialsAccepted property in the action

mappings for the view and set it to P to accept partiallyauthenticated users, not just registered ones


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Common Pitfalls: Web-Services

Problem:

Defined a web service response JSP (action mappingand global forward in the struts-config-ext.xml), butresponse is never received

Cause:

Web service definitions are in struts-wc-webservices.xml

Definitions in any other struts xml files will not beregistered when a web service is executed

Solution:

Define the action mappings and global forwards for webservices in the struts-wc-webservices.xml


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Common Pitfalls: Store Publish

Problem:

Publishing custom store archive (SAR) fails with:

The store archive is not compatible with STRUTS.Migrate this store archive to STRUTS before publishing."

Cause :

A pre-6.0 SAR contains used VIEWREG and URLREG,and have no information for the struts configuration files

Solution:

You need to include struts configuration information inthe SAR prior to publishing it

Refer to the InfoCenter document for full details,Updating the Web application configuration


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Must Gather: Struts

Trace components:

com.ibm.websphere.commerce.WC_SERVER=all

org.apache.struts.*=all

/WEB-INF/web.xml

/WEB-INF/struts-config*.xml For action forms and validation:

/WEB-INF/validator-rules.xml,/WEB-INF/validation.xml

For tiles:

/WEB-INF/tiles-defs.xml

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Summary

Implement MVC architecture with Struts framework

Web request processing flow:

Servlet Filter any cached or non-cached request

ActionServlet routes request to appropriate module

RequestProcessor determines action based on configBaseAction - bridges incoming request to business logic

Business Logic Faade invokes controller command

Represent views and URL mappings with global-forwards andaction-mappings within the module-specific struts config XMLs

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References

Apache Struts:http://struts.apache.org/

MustGather: WebSphere Commerce Struts framework problemshttp://www-1.ibm.com/support/docview.wss?uid=swg21257367

WebSphere Commerce Struts Framework http://publib.boulder.ibm.com/infocenter/wchelp/v6r0m0/index.jsp?to

pic=/com.ibm.commerce.developer.doc/concepts/csdstrutskeycompons.htm

Struts Tutorials: http://publib.boulder.ibm.com/infocenter/wchelp/v6r0m0/index.jsp?to

pic=/com.ibm.commerce.developer.tutorial.doc/tutorial/ttdstrutsview-intro.htm

http://publib.boulder.ibm.com/infocenter/wchelp/v6r0m0/index.jsp?topic=/com.ibm.commerce.developer.tutorial.doc/tutorial/ttdstrutsaction-intro.htm

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wste struts presenation 10-18-07

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