Stripes presentation for the Portuguese JUG session at JavaPT09 event. Last version available at Speaker Deck: http://speakerdeck.com/samaxes/java-web-development-with-stripes.

1. Java Web Development with Stripes
Samuel Santos

2. About me
• Senior Java Engineer and Web Advocate at
Present Technologies
• Open source enthusiast
• Web standards contributor
• Casual blogger
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3. Agenda
• Why
• What is it
• Goals
• Setting up
• Features
• Extensions
• Find more
• Q&A
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4. Why
“Java web development doesn’t have to suck.”
Tim Fennell, Stripes author
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5. Why
“Have you ever used a framework and felt you
had to do too much work for the framework
compared to what the framework gave you in
return?”
Freddy Daoud, Stripes Book
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6. What is it
• Stripes is a Model-View-Controller (MVC)
framework
• Stripes is not a “full-stack” framework
• Stripes is an action-based framework
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7. Goals
• Make developing web applications in Java
easy
• Provide simple yet powerful solutions to
common problems
• Make the Stripes ramp up time for a new
developer less than 30 minutes
• Make it really easy to extend Stripes, without
making you configure every last thing
From Stripes Homepage
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8. Setting up
<filter>
<filter-name>StripesFilter</filter-name>
<filter-class>net.sourceforge.stripes.controller.StripesFilter</filter-class>
<init-param>
<param-name>ActionResolver.Packages</param-name>
<param-value>com.example.javapt09.stripes.action</param-value>
</init-param>
</filter>
<servlet>
<servlet-name>DispatcherServlet</servlet-name>
<servlet-class>net.sourceforge.stripes.controller.DispatcherServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<filter-mapping>
<filter-name>StripesFilter</filter-name>
<servlet-name>DispatcherServlet</servlet-name>
<dispatcher>REQUEST</dispatcher>
<dispatcher>FORWARD</dispatcher>
<dispatcher>ERROR</dispatcher>
</filter-mapping>
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>*.action</url-pattern>
</servlet-mapping>
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9. Features - Smart binding
URLs binding
public class SmartBindingActionBean extends BaseActionBean {
...
}
<s:link beanclass="com.example.javapt09.stripes.action.SmartBindingActionBean">Smart binding</s:link>
<s:link href="${contextPath}/SmartBinding.action">Smart binding</s:link>
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10. Features - Smart binding
<s:form beanclass="com.example.javapt09.stripes.action.SmartBindingActionBean">
<p>
<s:label for="user.firstName" />
<s:text id="user.firstName" name="user.firstName" />
Parameters </p>
<p>
<s:label for="user.lastName" />
And Events </p>
<p>
<s:text id="user.lastName" name="user.lastName" />
<s:submit name="print" />
</p>
</s:form>
public class SmartBindingActionBean extends BaseActionBean {
@ValidateNestedProperties({
@Validate(field = "firstName", required = true, maxlength = 100),
@Validate(field = "lastName", required = true, maxlength = 100)
})
private User user;
public User getUser() { return user; }
public void setUser(User user) { this.user = user; }
@DefaultHandler
@DontValidate
public Resolution main() {
return new ForwardResolution("/WEB-INF/jsp/binding-validation.jsp");
}
public Resolution print() {
getContext().getMessages().add(new LocalizableMessage(
"com.example.javapt09.stripes.action.SmartBindingActionBean.print.success", user));
return new RedirectResolution(SmartBindingActionBean.class);
}
}
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11. Features - Smart binding
Localized buttons and labels
<s:form beanclass="com.example.javapt09.stripes.action.SmartBindingActionBean">
<p>
<s:label for="user.firstName" />
<s:text id="user.firstName" name="user.firstName" />
</p>
<p>
<s:label for="user.lastName" />
<s:text id="user.lastName" name="user.lastName" />
</p>
<p>
<s:submit name="print" />
</p>
</s:form>
com.example.javapt09.stripes.action.SmartBindingActionBean.user.firstName=First name
com.example.javapt09.stripes.action.SmartBindingActionBean.user.lastName=Last name
com.example.javapt09.stripes.action.SmartBindingActionBean.print=Print
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12. Features - Validation
Frequently used @Validate attributes
Attribute Type Description
field String Name of nested field to validate.
required boolean true indicates a required field.
on String[] Event handlers for which to apply.
minlength int Minimum length of input.
maxlength int Maximum length of input.
expression String EL expression to validate the input.
mask String Regular expression that the input must match.
minvalue double Minimum numerical value of input.
maxvalue double Maximum numerical value of input.
converter Class Type converter to use on the input.
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13. Features - Validation
Automatic maxlength on text inputs
public class SmartBindingActionBean extends BaseActionBean {
@ValidateNestedProperties({
@Validate(field = "firstName", required = true, maxlength = 100),
@Validate(field = "lastName", required = true, maxlength = 100)
})
private User user;
...
}
<form action="/javapt09/SmartBinding.action" method="post">
<p>
<label for="user.firstName">First name</label>
<input id="user.firstName" maxlength="100" name="user.firstName" type="text" />
</p>
<p>
<label for="user.lastName">Last name</label>
<input id="user.lastName" maxlength="100" name="user.lastName" type="text" />
</p>
<p>
<input name="print" value="Print" type="submit" />
</p>
</form>
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14. Features - Validation
Custom Validation
@ValidationMethod
public void validate(ValidationErrors errors) {
if (user.getLastName().equals(user.getFirstName())) {
errors.add("lastName",
new SimpleError("First and last name must be different!"));
}
}
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15. Features - Validation
Displaying errors and messages
• Messages
<s:messages />
• All errors
<s:errors />
• Specific field error
<s:errors field="user.firstName" />
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16. Features - Customizable URLs
Clean URLs
<servlet-mapping>
<servlet-name>DispatcherServlet</servlet-name>
<url-pattern>/action/*</url-pattern>
</servlet-mapping>
@UrlBinding("/action/cleanURL/{$event}/{city}")
public class CustomizableURLActionBean extends BaseActionBean {
private String city;
public Resolution delete() { ... }
}
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17. Features - Layouts
Reusable layout
<%@include file="/WEB-INF/jsp/common/taglibs.jsp" %>
<s:layout-definition>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>${title}</title>
<link rel="stylesheet" type="text/css" href="${contextPath}/css/style.css" />
</head>
<body>
<div id="header">
<span class="title">${title}</span>
</div>
<div id="body">
<s:layout-component name="body" />
</div>
</body>
</html>
</s:layout-definition>
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18. Features - Layouts
Using a reusable layout to render a page
<%@include file="/WEB-INF/jsp/common/taglibs.jsp" %>
<s:layout-render name="/WEB-INF/jsp/common/layout-main.jsp"
title="JavaPT09 - Stripes » Layouts">
<s:layout-component name="body">
<p>Main page content...</p>
</s:layout-component>
</s:layout-render>
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19. Features - Layouts
Final result
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>JavaPT09 - Stripes » Layouts</title>
<link rel="stylesheet" type="text/css" href="/javapt09/css/style.css" />
</head>
<body>
<div id="header">
<span class="title">JavaPT09 - Stripes » Layouts</span>
</div>
<div id="body">
<p>Main page content...</p>
</div>
</body>
</html>
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20. Features - Exception handling
<init-param>
<param-name>DelegatingExceptionHandler.Packages</param-name>
<param-value>com.example.javapt09.stripes.exception</param-value>
</init-param>
public class DefaultExceptionHandler implements AutoExceptionHandler {
public Resolution handle(Exception exception,
HttpServletRequest request, HttpServletResponse response) {
// Handle Exception
return new ForwardResolution(ErrorActionBean.class);
}
public Resolution handle(IOException exception,
HttpServletRequest request, HttpServletResponse response) {
// Handle IOException
return new ForwardResolution(ErrorActionBean.class);
}
}
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21. Features - Exception handling
Don’t catch your exceptions
public Resolution handledException() throws IOException {
throw new IOException("Handled exception");
}
public Resolution unhandledException() throws Exception {
throw new Exception("Unhandled exception");
}
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22. Features - Interceptors
Built-in interceptors
@Before(stages = LifecycleStage.BindingAndValidation)
public void prepareSomeStuff() {
// load data from the DB
}
Stripes request processing lifecycle stages:
RequestInit ActionBeanResolution HandlerResolution
BindingAndValidation CustomValidation EventHandling
ResolutionExecution RequestComplete
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23. Features - Interceptors
Custom interceptors
public interface Interceptor {
Resolution intercept(ExecutionContext context) throws Exception;
}
@Intercepts(LifecycleStage.ActionBeanResolution)
public class EJBInterceptor implements Interceptor {
public Resolution intercept(ExecutionContext context) throws Exception {
...
}
}
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24. Features - Easy Ajax integration
public class AjaxActionBean extends BaseActionBean {
private List<String> cities = new ArrayList<String>();
public Resolution load() {
return new JavaScriptResolution(cities);
}
}
<div id="cities"></div>
<script type="text/javascript">
var client = new XMLHttpRequest();
client.open("GET", "${contextPath}/Ajax.action?load=");
client.onreadystatechange = function() {
if (this.readyState == 4) {
var cities = eval(client.responseText);
var citiesList = "";
for (var i = 0; i < cities.length; i++) {
citiesList += "<li>" + cities[i] + "</li>";
}
document.getElementById("cities").innerHTML = "<ul>" + citiesList + "</ul>";
}
}
client.send(null);
</script>
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25. Features - File download
public class DownloadActionBean extends BaseActionBean {
@DefaultHandler
public Resolution main() throws FileNotFoundException {
String fileName = "stripes.png";
String filePath = getContext().getServletContext().getRealPath("/img/" + fileName);
return new StreamingResolution("image/png",
new FileInputStream(filePath)).setFilename(fileName);
}
}
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26. Features - File upload
File upload form
<s:form beanclass="com.example.javapt09.stripes.action.UploadActionBean"
enctype="multipart/form-data">
<p>
<s:file name="fileBean" />
</p>
<p>
<s:submit name="upload" />
</p>
</s:form>
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27. Features - File upload
Saving the file
public class UploadActionBean extends BaseActionBean {
private FileBean fileBean;
public FileBean getFileBean() { return fileBean; }
public void setFileBean(FileBean fileBean) { this.fileBean = fileBean; }
@DefaultHandler
public Resolution main() {
return new ForwardResolution("/WEB-INF/jsp/file-upload.jsp");
}
public Resolution upload() throws IOException {
fileBean.getFileName();
fileBean.getSize();
fileBean.getContentType();
// fileBean.save(new File());
return new ForwardResolution("/WEB-INF/jsp/file-upload.jsp");
}
}
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28. Features - Extension/customization
• Stripes uses auto-discovery to find extensions
<init-param>
<param-name>Extension.Packages</param-name>
<param-value>com.example.javapt09.stripes.extensions</param-value>
</init-param>
• The specified packages will be scanned for
extensions like interceptors, formatters, type
converters, exception handlers, etc
@Validate(maxlength = 100, converter = EmailTypeConverter.class)
private String email;
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29. Extensions
• Spring integration (built-in)
http://www.stripesframework.org/display/stripes/Spring
+with+Stripes
• EJB3 integration
http://code.google.com/p/stripes-ejb3
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30. Extensions
• Stripes Security (roles based)
http://www.stripesframework.org/display/stripes/Securi
ng+Stripes+With+ACLs
• Stripes Security (custom authorization)
http://www.stripesframework.org/display/stripes/Securit
y+Interceptor+for+custom+authorization
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31. Extensions
• Stripes-Reload
Plugin for Stripes 1.5 that reloads modifications
made to your Action Beans, Type Converters,
Formatters, and Resource Bundles without having to
restart your server
http://www.stripesbook.org/stripes-reload.html
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32. Find more
• Stripes Framwork
http://www.stripesframework.org
• Stripes Book: Stripes ...and Java Web
Development Is Fun Again
http://www.pragprog.com/titles/fdstr
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33. Q&A
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34. Contacts
• Present Technologies
http://www.present-technologies.com
• Blog
http://www.samaxes.com
• Twitter
http://twitter.com/samaxes
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