Struts Petstore

Struts University Series

Abstract

Struts has always shipped with a simple example application. But for many teams,

MailReader is a bit too simple. Struts Petstore is a full-featured, production-grade Struts application inspired by the infamous

Java Pet Store. Struts Petstore uses a professional architecture that hooks up to

Apache iBATIS for data access. Let's have a look ...

Struts PetStore

A little background

Sun creates J2EE Pet StoreDemonstrates patterns

Microsoft creates .NET Pet ShopDemonstrates performance

Clinton Begin creates JPetStoreDemonstrates iBATIS

iBATIS and Struts

iBATISData mapping framework for SQLCompares to Hibernate and OJB

StrutsWeb application framework Compares to WebWork and Tapestry

Clinton Begin Inventor of iBATIS and author of JPetStore

The Purpose of JPetStore

Clinton Begin wrote JPetstore to showJava is easyJava is low costJava is highly productiveJava enables choiceJava enables change

The Purpose of JPetStore

Clinton Begin wrote JPetstore to showJava is easyJava is low costJava is highly productiveJava enables choiceJava enables change iBATIS is cool

Advantages without Tradeoffs

JPetStore uses superior design and architectureClearly defined application layersUses known best practices and patternsAvoids known worst practices

No stored proceduresNo SQL embedded in Java codeNo HTML in the databaseNo generated code

Presentation

Model View Controller PatternWell know and proven (GOF)Simple and maintainable

Apache StrutsFreely available, open sourceBased on JavaBeans

Domain

JavaBeans Components with properties and behavior Plug into presentation and persistence layers Compatible with many frameworks GUI tools available (IDEs, et cetera)

Logic Classes None/Verb separation More maintainable than prior versions

Persistence

Data Access Objects “Pluggable” persistance components Proven abstract factory pattern (GoF) Improves maintainability and flexibility

SQL Maps Reduces/eliminates repetive JDBC code Improves performance with caching Portable across many databases Based on JavaBeans

Link to a category query

JavaServer Page:

<html:link page="/shop/viewCategory.shtml?categoryId=DOGS">

Struts Config:

<action path="/shop/viewCategory" type="com.ibatis.struts.BeanAction"

name="catalogBean" scope="session" validate="false" > <forward name="success"

path="/catalog/Category.jsp"/> </action>

CatalogBean

public String viewCategory() {

if (categoryId != null) {

productList = catalogService.getProductListByCategory(categoryId);

category = catalogService.getCategory(categoryId);

}

return "success";

}

CatalogService

public PaginatedList getProductListByCategory(String categoryId) {

return queryForPaginatedList("getProductListByCategory", categoryId, PAGE_SIZE);

}

public Category getCategory(String categoryId) {

return (Category) queryForObject("getCategory", categoryId);

}

SqlMaps

<select id="getCategoryList" resultMap="categoryResult">

select CATID, NAME, DESCN from CATEGORY

</select>

<select id="getCategory" resultMap="categoryResult" parameterClass="string">

select CATID, NAME, DESCN from CATEGORY where CATID = #value#

</select>

ResultMap

<resultMap id="categoryResult" class="category">

<result property="categoryId" column="CATID"/>

<result property="name" column="NAME"/>

<result property="description" column="DESCN"/>

</resultMap>

Cache Model

<cacheModel id="oneDayCategory" type="LRU">

<flushInterval hours="24"/>

</cacheModel>

Cache Model

<cacheModel id="oneDayCategory" type="LRU">

<flushInterval hours="24"/>

<flushOnExecute statement="insertCategory"/>

</cacheModel>

Dynamic SQL

<select id="getCategoryList" resultMap="categoryResult">

select CATID, NAME, DESCN from CATEGORY

</select>

<select id="getCategory" resultMap="categoryResult" parameterClass="string">

select CATID, NAME, DESCN from CATEGORY where CATID = #value#

</select>

Dynamic SQL

<select id="getCategory" resultMap="categoryResult" parameterClass="string">

select CATID, NAME, DESCN from CATEGORY

<dynamic prepend="WHERE">

<isParameterPresent>

where CATID = #value#

</isParameterPresent>

</dynamic>

</select>

Struts University Series