- The document discusses the Stripes framework, an alternative to Struts for building Java web applications. It highlights some key advantages of Stripes such as simpler configuration without XML files, convention-based programming, and built-in features like validation and internationalization. - Stripes uses annotations and conventions rather than external configuration files. Event handlers in action beans return resolutions to control application flow rather than forwarding. Validation is implemented through annotations rather than XML. - The document provides an overview of fundamental Stripes concepts such as action beans, URL binding, validation, type conversion, and JSP tags, contrasting them with the typical Struts approach. It argues Stripes makes web development in Java easier through its simplified and intuitive programming

1. Stripes Framework
...in a comparison with Struts!
Johannes Carlén
johannes.carlen@callistaenterprise.se
www.callistaenterprise.se

2. Let's talk about Struts for a minute...
• Pros • Cons
– De facto standard for a – Simpler then than now
couple of years – struts-config.xml (form
– Simple and powerful beans, global forwards, action
concept. Easy to mappings with forwards, message
understand resources, plugins, etc..)
– Stable and mature – Validation
– Documentation. Internet – Property Binding
and books – Confusing JSP-tags
– Easy to find skilled – Layout
developers
Stripes Framework, Slide 2
© Copyright 2009, Callista Enterprise AB

3. Ok, so what is this Stripes thing?
• Around since 2005 (Tim Fennell)
• Built upon the same design pattern (MVC) and concepts
as Struts.
• An action based framework
• Exisiting skills in Struts is easily transferred to Stripes –
no new concepts to learn
• Claim: ”...makes developing web applications in Java
easy”
Stripes Framework, Slide 3
© Copyright 2009, Callista Enterprise AB

4. Tell me in a language I understand, please
• Coding by convention & Annotations
• No external configuration
• URL Binding
• Event Handlers (multiple events form)
• Property Binding / Type Conversion (nested properties)
• Interceptors for cross cutting concerns
Stripes Framework, Slide 4
© Copyright 2009, Callista Enterprise AB

5. And what's in the box?
• Validation mechanisms
• Exception handling
• JSP-tags
• Layout
• Localization
• Testing (Out of container with mock objects)
• Easy to extend
Stripes Framework, Slide 5
© Copyright 2009, Callista Enterprise AB

6. The fundamentals
• Action Beans & Event Handlers
• URL Binding
• Validation
• Type Conversion and Formatters
• JSP Tags & Layout
Stripes Framework, Slide 6
© Copyright 2009, Callista Enterprise AB

7. The Struts way - Actions
Action Class
public class CustomerAction extends DispatchAction {
public ActionForward save(ActionMapping mapping,
ActionForm form, struts-config.xml
HttpServletRequest request,
HttpServletResponse response)
throws Exception { <?xml version="1.0" encoding="ISO-8859-1" ?>
<!DOCTYPE struts-config PUBLIC
CustomerForm customerForm = (CustomerForm) form; "-//Apache Software Foundation//DTD Struts Configuration 1.1//EN"
// Validate form "http://jakarta.apache.org/struts/dtds/struts-config_1_1.dtd">
if (!isValid(form, mapping, request { <struts-config>
CustomerForm. <form-beans>
setCustomers(customerService.findAllCustomers()); <form-bean name="customerForm" type="se.callistaenterprise.exampleweb.CustomerForm" />
return mapping.getInputForward(); </form-beans>
} <global-exceptions>
Customer customer = (Customer) customerForm. <exception type="se.callistaenterprise.examplecommon.BaseException"
getCustomerBean().extract(); handler="se.callistaenterprise.exampleweb.action.BaseExceptionHandler"
customerService.saveCustomer(customer, key="errors.general"/>
NumericUtils.toLong(customerForm.getCustomerId())); </global-exceptions>
return mapping.findForward(FORWARD_SUCCESS); <global-forwards>
} <forward name="start" path="/start.do" redirect="true"/>
</global-forwards>
<action-mappings>
<action path="/customer"
type="org.springframework.web.struts.DelegatingActionProxy"
Form Bean scope="request"
parameter="task"
input=".customer.save"
public class BaseForm extends ValidatorForm {
name="customerForm"
private CustomerBean customer;
validate="false">
private String startDate;
<forward name="success" path="/customer/customer.do?task=edi
public CustomerBean getCustomer() {return customer;}
redirect="true" />
public void setCustomer(CustomerBean customer)
<forward name="failure_redirect" path="/customer/list.do" redirect="true" />
{this.customer=customer;}
</action>
public String getStartDate() {return startDate;}
</action-mappings>
public void setStartDate(String date){this.startDate=date;}
<plug-in className="org.apache.struts.tiles.TilesPlugin">
}
<set-property property="definitions-config" value="/WEB-INF/tiles-defs.xml" />
<set-property property="moduleAware" value="true" />
<set-property property="definitions-parser-validate" value="true" />
View helper bean </plug-in>
</struts-config>
public class CustomerBean {
private String id;
private String name;
private String email;
public String getId() {return id;}
public void setId(String id) {this.id=id;}
public String getName() {return name;}
public void setName(String name) {this.name=name;}
Stripes Framework, Slide 7
public String getEmail() {return email;}
public void setEmail(String email) {this.email=email;}
} © Copyright 2009, Callista Enterprise AB

8. The fundamentals – Action Beans
• Handles an action and encapsulates the model beans
• Implements the ActionBean interface:
public interface ActionBean {
public ActionBeanContext getContext();
public void setContext(ActionBeanContext context);
}
Stripes Framework, Slide 8
© Copyright 2009, Callista Enterprise AB

9. The Struts way – Dispatch Actions
public class CustomerAction extends DispatchAction {
public ActionForward save(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception {
CustomerForm customerForm = (CustomerForm) form;
if (!isValid(form, mapping, request {
CustomerForm.setCustomers(customerService.findAllCustomers());
return mapping.getInputForward();
}
Customer customer = (Customer) customerForm.getCustomerBean().extract();
customerService.saveCustomer(customer,customerForm.getCustomerId()));
return mapping.findForward(FORWARD_SUCCESS);
}
Stripes Framework, Slide 9
© Copyright 2009, Callista Enterprise AB

10. The fundamentals – Event Handlers
• Stripes responds to a request and invokes a method in
the action bean – an event handler.
• Action Bean method
– has no parameters and returns a Resolution
public class CustomerActionBean implements ActionBean {
@Validate
private Customer customer;
public Resolution save() {
customerManager.save(this.customer);
return new ForwardResolution("/WEB-INF/pages/customers.jsp");
}
...
}
Stripes Framework, Slide 10
© Copyright 2009, Callista Enterprise AB

11. Resolutions
• Tells Stripes what to do next in a request
• Examples:
new ForwardResolution(”/WEB-INF/pages/my.jsp”);
new ForwardResolution(AnotherActionBean.class,”someEvent”);
new RedirectResolution(”/some/other.jsp”);
new StreamingResolution(”application/pdf”,myStream);
Stripes Framework, Slide 11
© Copyright 2009, Callista Enterprise AB

12. The fundamentals
• Action Beans & Event Handlers
• URL Binding
• Validation
• Type Conversion and Formatters
• JSP Tags & Layout
Stripes Framework, Slide 12
© Copyright 2009, Callista Enterprise AB

13. The Struts way – URL Binding
struts-config.xml
<action-mappings>
<action path="/customer"
type="org.springframework.web.struts.DelegatingActionProxy"
scope="request"
parameter="task"
input=".customer.save"
name="customerForm"
validate="false">
<forward name="success" path="/customer.do?task=edit" redirect="true" />
<forward name="failure" path="/customer.do?task=list" redirect="true" />
</action>
</action-mappings>
Stripes Framework, Slide 13
© Copyright 2009, Callista Enterprise AB

14. The fundamentals - URL Binding
• By convention
The action bean class:
se.callistaenterprise.web.store.CustomerActionBean
...defaults to:
http://myserver/mycontext/store/Customer.action
Stripes Framework, Slide 14
© Copyright 2009, Callista Enterprise AB

15. The fundamentals - URL Binding
• Override using @UrlBinding
@UrlBinding(”/customer/{$event}.html”)
public class CustomerAction implements ActionBean {
public Resolution save() {
...
}
}
– Use this URL to trigger event:
http://myserver/mycontext/customer/save.html
Stripes Framework, Slide 15
© Copyright 2009, Callista Enterprise AB

16. The fundamentals
• Action Beans & Event Handlers
• URL Binding
• Validation
• Type Conversion and Formatters
• JSP Tags & Layout
Stripes Framework, Slide 16
© Copyright 2009, Callista Enterprise AB

17. The Struts way – Validation
• Validation in action method, form bean, validator.xml and
validator-rules.xml
Action Class Form Bean
public class CustomerAction extends DispatchAction { public class CustomerBeann extends ActionForm {
public ActionForward save(ActionMapping mapping, public ActionErrors validate(ActionMapping mapping,
ActionForm form, HttpServletRequest request) {
HttpServletRequest request, ActionErrors actionErrors = new ActionErrors();
HttpServletResponse response) // validate credit
throws Exception { if (credit > Credit.LIMIT) {
actionErrors.add("credte", new ActionMessage("error.name"));
CustomerForm customerForm = (CustomerForm) form; }
// Validate form return actionErrors;
if (!isValid(form, mapping, request { }
CustomerForm. ...
setCustomers(customerService.findAllCustomers());
return mapping.getInputForward();
}
Customer customer = (Customer) customerForm.
getCustomerBean().extract();
customerService.saveCustomer(customer,
NumericUtils.toLong(customerForm.getCustomerId())); validator-rules.xml
return mapping.findForward(FORWARD_SUCCESS);
} <validator name="email"
classname="org.apache.struts.validator.FieldChecks"
method="validateEmail"
methodParams="java.lang.Object,
org.apache.commons.validator.ValidatorAction,
validator.xml org.apache.commons.validator.Field,
org.apache.struts.action.ActionMessages,
org.apache.commons.validator.Validator,
<form name="customerForm"> javax.servlet.http.HttpServletRequest"
<field property="customerBean.customerId" depends="required"> depends="" msg="errors.email" />
<arg name="required" key="action.customer.customerId" position="0" />
</field>
<field property="customerBean.customer.namn" depends="required">
<arg name="required" key="action.customer.namn" position="0" />
</field>
<field property="customerBean.customer.email" depends="email">
<arg0 key="action.customer.email" />
</field>
</form>
Stripes Framework, Slide 17
© Copyright 2009, Callista Enterprise AB

18. The fundamentals - Validation
• Using @Validate
(field,required,on,minlength,maxlength,expression,mask,minvalue,maxvalue,
converter,trim,label,ignore,encrypted)
@Validate(required=true,minlength=8, maxlength=32)
private String password
@Validate(required=true, expression=”this>=startDate”,
converter=DateConverter.class)
private Date endDate;
@ValidateNestedProperties({
@Validate(field=”email” required=true, on=”save”),
@Validate(field=”name” requried=true, on=”save”)})
private Customer customer;
Stripes Framework, Slide 18
© Copyright 2009, Callista Enterprise AB

19. The fundamentals - Validation
• Custom validation with @ValidationMethod
@ValidationMethod(on=”save”)
public void validateCustomerUsername() {
if(customerManager.usernameExists(customer.getUsername)){
// Add validation error
}
}
Stripes Framework, Slide 19
© Copyright 2009, Callista Enterprise AB

20. The fundamentals
• Action Beans & Event Handlers
• URL Binding
• Validation
• Type Conversion and Formatters
• JSP Tags & Layout
Stripes Framework, Slide 20
© Copyright 2009, Callista Enterprise AB

21. The Struts way – Type conversion
• Conversion in action class.
CustomerAction.java
...
CustomerForm customerForm = (CustomerForm) form;
Customer customer = new Customer();
float credit = Float.parseFloat(customerForm.getCredit());
c.setCredit(credit);
...
Customer.java
private float credit;
public float getCredit() {return credit;}
public void setCredit(float credit) {this.credit=credit;}
Stripes Framework, Slide 21
© Copyright 2009, Callista Enterprise AB

22. The fundamentals – Type Conversion
• Used for parameter binding
• Built in converters for standard types (numericals, booleans, enums,
email, credit card, one-to-many)
• Write your own custom converter by implementing the
TypeConverter<T> interface
Stripes Framework, Slide 22
© Copyright 2009, Callista Enterprise AB

23. The fundamentals – Type Conversion
• Example - converting String to PhoneNumber
MyActionBean.java
@Validate(required=true, converter=PhoneNumberConverter.class)
private PhoneNumber phoneNumber;
PhoneNumberConverter.java
public class PhoneNumberConverter implements TypeConverter<PhoneNumber> {
@Override
public PhoneNumber convert(String input, Class<? extends PhoneNumber> targetType,
Collection<ValidationError> errors) {
try {
PhoneNumber phoneNumber = new PhoneNumber(input);
return phoneNumber;
} catch (IllegalArgumentException e) {
errors.add(new ScopedLocalizableError("converter.phonenumber",
"invalidPhoneNumber"));
return null;
}
}
...
}
Stripes Framework, Slide 23
© Copyright 2009, Callista Enterprise AB

24. The fundamentals – Formatters
• Type conversion in the opposite direction
• An object is converted to a String to be displayed to the user
• Locale-sensitive
• Write a custom formatter by implementing the Formatter interface
• Best practice - use the same class to implement both TypeConverter
and Formatter
Stripes Framework, Slide 24
© Copyright 2009, Callista Enterprise AB

25. The fundamentals
• Action Beans & Event Handlers
• URL Binding
• Validation
• Type Conversion and Formatters
• JSP Tags & Layout
Stripes Framework, Slide 25
© Copyright 2009, Callista Enterprise AB

26. The Struts way – JSP tags
• Example of a simple JSP:
editCustomer.jsp
<html:form action="/customer">
<html:errors />
<html:hidden property="customerId" />
<bean:message key=”customer.company” />
<html:select property="customerCompanyId">
<hmtl:optionsCcollection property="companies" value="id" label="name" />
</html:select>
<bean:message key=”customer.name.and.phone” />
<html:text property="customer.name"/>
<html:text property="customer.phoneNumber"/>
</html:form>
Stripes Framework, Slide 26
© Copyright 2009, Callista Enterprise AB

27. The Fundamentals - JSP tags
• JSP tags equivalent to Struts HTML tags
• Uses the name attribute to bind a value to an action bean property
• Labels from resource bundles
• All HTML attributes
editcustomer.jsp
<stripes:form action="/customer.html">
<stripes:errors />
<stripes:hidden name="customer.id" />
<stripes:select name="customer.company.id">
<stripes:options-collection collection="${actionBean.companies}"
value="id" label="name" />
</stripes:select>
<stripes:text name="customer.name" style=”customerLabels” />
<stripes:text name="customer.phoneNumber" />
</stripes:form>
Stripes Framework, Slide 27
© Copyright 2009, Callista Enterprise AB

28. The Tiles way – JSP layout
tiles-def.xml
<tiles-definitions>
<definition name=".layout" path="/WEB-INF/pages/layout/layout.jsp">
<put name="menu" value="/WEB-INF/pages/topmenu.jsp"/> struts-config.xml
<put name="body" value="/WEB-INF/pages/start.jsp"/>
<plug-in
</definition> className="org.apache.struts.tiles.TilesPlugin">
<definition name=".customer.view" extends=".layout"> <set-property property="definitions-config"
value="/WEB-INF/tiles-defs.xml" />
<put name="body" value="/WEB-INF/pages/customer/view.jsp"/> <set-property property="moduleAware"
value="true" />
</definition> <set-property property="definitions-parser-
<definition name=".customer.edit" extends=".layout"> validate" value="true" />
</plug-in>
<put name="body" value="/WEB-INF/pages/customer/edit.jsp"/>
<action path="/customer"
</definition> type="org.apache.struts.actions.ForwardAction"
<tiles-definitions> parameter="homepage"/>
layout.jsp
<html>
<body>
<tiles:insert attribute="menu"/>
<tiles:insert attribute="body"/>
</body>
</html>
edit.jsp
<h1>On this page you can edit the
view.jsp customer</h1>
Stripes Framework, Slide 28
<h1>This page outputs the customer</h1>
© Copyright 2009, Callista Enterprise AB

29. The Fundamentals - JSP layout
• No configuration
• Concepts: Layout, Renderer, Component, Attributes
• Three tags: layout-definition, layout-render, layout-component
layout.jsp
<stripes:layout-definition>
<h1>${title}</h1>
<stripes:layout-component name=”${menu}”/>
My default menu</stripes:layout-component>
<stripes:layout-component name=”body”/>
</stripes:layout-definition>
view.jsp (renderer)
<stripes:layout-render name=”/WEB-INF/pages/layout.jsp”
title=”View customer”>
<stripes:layout-component name=”body”/>
Output the customer..</stripes:layout-component>
</stripes:layout-render>
Stripes Framework, Slide 29
© Copyright 2009, Callista Enterprise AB

30. More features
• Web Flows
• Interceptors
• Localization, Messages and Validation Errors
• Testing
Stripes Framework, Slide 30
© Copyright 2009, Callista Enterprise AB

31. The Struts Way – No flow
• No mechanism in Struts for wizard-like functionality
• Alternatives: Struts Flow (sandbox), Spring Web Flow
• ..or by hand
Stripes Framework, Slide 31
© Copyright 2009, Callista Enterprise AB

32. The Stripes Wizard
• The @Wizard annotation
– generates hidden inputs for already submitted fields
– keeps track of which fields are to be validated for each step
@Wizard
public class CustomerActionBean implements ActionBean {
public Resolution view() {...}
public Resolution save() {...}
}
Stripes Framework, Slide 32
© Copyright 2009, Callista Enterprise AB

33. More features
• Web Flows
• Interceptors
• Localization, Messages and Validation Errors
• Testing
Stripes Framework, Slide 33
© Copyright 2009, Callista Enterprise AB

34. The Struts way – Interceptors
• No real equivalent functionality in Struts
CustomerAction.java
public ActionForward view(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception {
CustomerForm customerForm = (CustomerForm) form;
customerForm.setCustomer(customerService.findCustomer(customerForm.getId()));
return mapping.findForward(FORWARD_SUCCESS_VIEW);
}
public ActionForward save(ActionMapping mapping,
ActionForm form,
HttpServletRequest request,
HttpServletResponse response) throws Exception {
CustomerForm customerForm = (CustomerForm) form;
Customer customer = (Customer) customerForm.getCustomerBean().extract();
customerService.saveCustomer(customer);
customerForm.setCustomer(customerService.findCustomer(customerForm.getId()));
return mapping.findForward(FORWARD_SUCCESS_VIEW);
}
Stripes Framework, Slide 34
© Copyright 2009, Callista Enterprise AB

35. Interceptors
• Code that is executed before and/or after a life cycle stage
• Two ways to intercept:
– Before / After methods (applies to a specific action bean)
– Global interceptor (intercepts all requests at given stages)
EST
R EQU
G
O MIN Request ActionBean Handler
INC
Init Resolution Resolution
Binding And
Validation
Custom
E
P ON S Validation
RES
NG
GOI
OUT Request Resolution Event
Complete Execution Handling
Stripes Framework, Slide 35
© Copyright 2009, Callista Enterprise AB

36. Interceptors
T
UE S
R EQ
NG
OM I
• Before and after methods
Request ActionBean Handler
INC Init Resolution Resolution
Binding And
– Add a method to an action bean Validation
SE Custom
– Annotate with @Before or @After GOI
NG
R ES
P ON Validation
OUT Request Resolution Event
Complete Execution Handling
@After(stages = LifecycleStage.BindingAndValidation, on = {"view”,”edit"})
public void populateCustomer() {
customer = customerManager.findById(customer.getId());
}
Stripes Framework, Slide 36
© Copyright 2009, Callista Enterprise AB

37. Interceptors
EST
R EQU
NG
OM I Request ActionBean Handler
INC
• Global Interceptor
Init Resolution Resolution
Binding And
Validation
– Implement the Interceptor interface Custom
E
ONS
ESP Validation
and indicate life cycle stages OUT
GOI
N GR
Request Resolution Event
Complete Execution Handling
}
@Intercepts(LifecycleStage.EventHandlingResolution)
public class AuditLogInterceptor implements Interceptor {
public Resolution intercept(ExecutionContext context) throws Exception
{
logEventStarted(context);
Resolution resolution = context.proceed();
logEventCompleted(context);
return resolution;
}
}
Stripes Framework, Slide 37
© Copyright 2009, Callista Enterprise AB

38. More features
• Web Flows
• Interceptors
• Localization, Messages and Validation Errors
• Testing
Stripes Framework, Slide 38
© Copyright 2009, Callista Enterprise AB

39. The Struts way – I18n and messages
• ApplicationResources.properties – single resource bundle
• Use the struts-bean taglib:
<bean:message key="app.name" />
• Use <html:errors/> and <html:messages/> to display validation
errors and messages
editCustomer.jsp
<html:form action="/customer">
<html:errors /><br />
<bean:message key=”customer.label.name” />
<html:text property="customer.name"/>
</html:form>
Stripes Framework, Slide 39
© Copyright 2009, Callista Enterprise AB

40. Localization, Messages & Validation Errors
• Localization relies on standard ResourceBundles
• JSTL with <fmt:message> for text
• Application messages and validation errors by key:
CustomerActionBean.java
@ValidationMethod(on=”save”)
public void validateCustomerUsername() {
if(customerManager.usernameExists(customer.getUsername)){
getContext.getValidationErrors.
add(new LocalizableError(”customer.invalid.username”,customer.getUsername());
}
}
editCustomer.jsp
<stripes:form action="/customer.html">
<stripes:errors /><br />
<fmt:message key=”customer.name” />
<stripes:text name="customer.name" style=”customerLabels” />
</stripes:form>
Stripes Framework, Slide 40
© Copyright 2009, Callista Enterprise AB

41. More features
• Web Flows
• Interceptors
• Localization, Messages and validation errors
• Testing
Stripes Framework, Slide 41
© Copyright 2009, Callista Enterprise AB

42. The Struts way – Out of container testing
• Struts TestCase on Sourceforge
• Mock objects
• Unit tests extends MockStrutsTestCase
public class TestCustomerAction extends MockStrutsTestCase {
public TestCustomerAction(String testName) { super(testName); }
public void testSave() {
setConfigFile("mymodule","/WEB-INF/struts-config.xml");
setRequestPathInfo("/customer.do");
addRequestParameter("task","save");
addRequestParameter("customer.email","NO_VALID_EMAIL_ADRESS");
actionPerform();
verifyForward("edit");
verifyActionErrors(new String[] {"error.invalid.email"});
}
}
Stripes Framework, Slide 42
© Copyright 2009, Callista Enterprise AB

43. Automated testing
• What?
– Submit a form, validating response with any validation errors
– Type conversion
– URL Bindings
– Interceptors
• How?
– Using mock objects for Session, Request, Response,
ServletContext objects etc)
– MockRoundtrip simulates requests to action beans
Stripes Framework, Slide 43
© Copyright 2009, Callista Enterprise AB

44. Test example
@Test
public void testEmailRequired() throws Exception {
MockRoundtrip trip = new MockRoundtrip(mockServletContext,
CustomerActionBean.class);
trip.setParameter("customer.email", "NO_VALID_EMAIL_ADRESS");
trip.execute("save");
assertEquals(1, trip.getValidationErrors().size());
}
Stripes Framework, Slide 44
© Copyright 2009, Callista Enterprise AB

45. Wrapping up
• Easy but still powerful MVC framework without the Struts caveats
• Short learning curve for existing Struts developers
– Manage in hours – control in a couple of days
• 30% less code (at least)
• Simplicity saves time
• Good documentation
• And yes the Stripes team's claim holds – Stripes really makes web
application development easier.
Stripes Framework, Slide 45
© Copyright 2009, Callista Enterprise AB

46. As simple as that...
Q&A
Johannes Carlén
johannes.carlen@callistaenterprise.se
www.callistaenterprise.se
Stripes Framework, Slide 46
© Copyright 2009, Callista Enterprise AB