Java Web Development with Stripes

Stripes framework presentation for the Portuguese JUG session at JavaPT09 event.

Transcript

1. Java Web Development with Stripes
   Samuel Santos
   

   View Slide

2. About me
   • Senior Java Engineer and Web Advocate at
   Present Technologies
   • Open source enthusiast
   • Web standards contributor
   • Casual blogger
   Present Technologies 2
   

   View Slide

3. Agenda
   • Why
   • What is it
   • Goals
   • Setting up
   • Features
   • Extensions
   • Find more
   • Q&A
   Present Technologies 3
   

   View Slide

4. Why
   “Java web development doesn’t have to suck.”
   Tim Fennell, Stripes author
   Present Technologies 4
   

   View Slide

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
   Present Technologies 5
   

   View Slide

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
   Present Technologies 6
   

   View Slide

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
   Present Technologies 7
   

   View Slide

8. Setting up
   Present Technologies 8
   
   StripesFilter
   net.sourceforge.stripes.controller.StripesFilter
   
   ActionResolver.Packages
   com.example.javapt09.stripes.action
   
   
   
   DispatcherServlet
   net.sourceforge.stripes.controller.DispatcherServlet
   1
   
   
   StripesFilter
   DispatcherServlet
   REQUEST
   FORWARD
   ERROR
   
   
   DispatcherServlet
   *.action
   
   

   View Slide

9. Features - Smart binding
   URLs binding
   Present Technologies 9
   public class SmartBindingActionBean extends BaseActionBean {
   ...
   }
   Smart binding
   Smart binding
   

   View Slide

10. Parameters
    And Events
    
    
    
    
    
    
    
    
    
    
    
    
    
    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);
    }
    }
    Features - Smart binding
    Present Technologies 10
    

    View Slide

11. Features - Smart binding
    Localized buttons and labels
    Present Technologies 11
    
    
    
    
    
    
    
    
    
    
    
    
    
    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
    

    View Slide

12. Features - Validation
    Frequently used @Validate attributes
    Present Technologies 12
    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.
    

    View Slide

13. Features - Validation
    Automatic maxlength on text inputs
    Present Technologies 13
    public class SmartBindingActionBean extends BaseActionBean {
    @ValidateNestedProperties({
    @Validate(field = "firstName", required = true, maxlength = 100),
    @Validate(field = "lastName", required = true, maxlength = 100)
    })
    private User user;
    ...
    }
    
    
    First name
    
    
    
    Last name
    
    
    
    
    
    
    

    View Slide

14. Features - Validation
    Custom Validation
    Present Technologies 14
    @ValidationMethod
    public void validate(ValidationErrors errors) {
    if (user.getLastName().equals(user.getFirstName())) {
    errors.add("lastName",
    new SimpleError("First and last name must be different!"));
    }
    }
    

    View Slide

15. Features - Validation
    Displaying errors and messages
    • Messages
    • All errors
    • Specific field error
    Present Technologies 15
    
    
    
    

    View Slide

16. Features - Clean URLs
    Customizable URLs
    Present Technologies 16
    
    DispatcherServlet
    /action/*
    
    @UrlBinding("/action/cleanURL/{$event}/{city}")
    public class CustomizableURLActionBean extends BaseActionBean {
    private String city;
    public Resolution delete() { ... }
    }
    

    View Slide

17. Features - Clean URLs
    DynamicMappingFilter
    Static resources can be delivered from the same namespace
    to which an ActionBean is mapped using clean URLs.
    Present Technologies 17
    
    DynamicMappingFilter
    net.sourceforge.stripes.controller.DynamicMappingFilter
    
    ActionResolver.Packages
    com.example.javapt09.stripes.action
    
    
    
    DynamicMappingFilter
    /*
    REQUEST
    FORWARD
    INCLUDE
    
    

    View Slide

18. Features - Layouts
    Reusable layout
    Present Technologies 18
    <%@include file="/WEB-INF/jsp/common/taglibs.jsp" %>
    
    
    
    
    
    ${title}
    
    
    
    
    ${title}
    
    
    
    
    
    
    
    

    View Slide

19. Features - Layouts
    Using a reusable layout to render a page
    Present Technologies 19
    <%@include file="/WEB-INF/jsp/common/taglibs.jsp" %>
    title="JavaPT09 - Stripes » Layouts">
    
    Main page content...
    
    
    

    View Slide

20. Features - Layouts
    Final result
    Present Technologies 20
    
    
    
    
    JavaPT09 - Stripes » Layouts
    
    
    
    
    JavaPT09 - Stripes » Layouts
    
    
    Main page content...
    
    
    
    

    View Slide

21. Features - Exception handling
    Present Technologies 21
    
    DelegatingExceptionHandler.Packages
    com.example.javapt09.stripes.exception
    
    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);
    }
    }
    

    View Slide

22. Features - Exception handling
    Don’t catch your exceptions
    Present Technologies 22
    public Resolution handledException() throws IOException {
    throw new IOException("Handled exception");
    }
    public Resolution unhandledException() throws Exception {
    throw new Exception("Unhandled exception");
    }
    

    View Slide

23. Features - Interceptors
    Built-in interceptors
    Stripes request processing lifecycle stages:
    Present Technologies 23
    @Before(stages = LifecycleStage.BindingAndValidation)
    public void prepareSomeStuff() {
    // load data from the DB
    }
    RequestInit ActionBeanResolution HandlerResolution
    BindingAndValidation CustomValidation EventHandling
    ResolutionExecution RequestComplete
    

    View Slide

24. Features - Interceptors
    Custom interceptors
    Present Technologies 24
    public interface Interceptor {
    Resolution intercept(ExecutionContext context) throws Exception;
    }
    @Intercepts(LifecycleStage.ActionBeanResolution)
    public class EJBInterceptor implements Interceptor {
    public Resolution intercept(ExecutionContext context) throws Exception {
    ...
    }
    }
    

    View Slide

25. Features - Easy Ajax integration
    Present Technologies 25
    public class AjaxActionBean extends BaseActionBean {
    private List cities = new ArrayList();
    public Resolution load() {
    return new JavaScriptResolution(cities);
    }
    }
    
    <br/>var client = new XMLHttpRequest();<br/>client.open("GET", "${contextPath}/Ajax.action?load=");<br/>client.onreadystatechange = function() {<br/>if (this.readyState == 4) {<br/>var cities = eval(client.responseText);<br/>var citiesList = "";<br/>for (var i = 0; i < cities.length; i++) {<br/>citiesList += "<li>" + cities[i] + "</li>";<br/>}<br/>document.getElementById("cities").innerHTML = "<ul>" + citiesList + "</ul>";<br/>}<br/>}<br/>client.send(null);<br/>
    

    View Slide

26. Features - File download
    Present Technologies 26
    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);
    }
    }
    

    View Slide

27. Features - File upload
    File upload form
    Present Technologies 27
    enctype="multipart/form-data">
    
    
    
    
    
    
    
    

    View Slide

28. Features - File upload
    Saving the file
    Present Technologies 28
    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");
    }
    }
    

    View Slide

29. Features - Extension/customization
    • Stripes uses auto-discovery to find extensions
    • The specified packages will be scanned for
    extensions like interceptors, formatters, type
    converters, exception handlers, etc
    Present Technologies 29
    
    Extension.Packages
    com.example.javapt09.stripes.extensions
    
    @Validate(maxlength = 100, converter = EmailTypeConverter.class)
    private String email;
    

    View Slide

30. Extensions
    • Spring integration (built-in)
    http://www.stripesframework.org/display/stripes/Spring
    +with+Stripes
    • Stripes Injection Enricher (support for @EJB,
    @Inject and @Resource)
    https://github.com/samaxes/stripes-injection-enricher
    Present Technologies 30
    

    View Slide

31. 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
    Present Technologies 31
    

    View Slide

32. Extensions
    • Stripes-Reload
    Reloads modifications made to your Action Beans,
    Type Converters, Formatters, and Resource Bundles
    without having to restart your server.
    http://code.google.com/p/stripes-reload/
    Present Technologies 32
    

    View Slide

33. Find more
    • Stripes Framework
    http://www.stripesframework.org
    • Stripes Book: Stripes ...and Java Web
    Development Is Fun Again
    http://pragprog.com/book/fdstr/stripes
    Present Technologies 33
    

    View Slide

34. Q&A
    Present Technologies 34
    

    View Slide

35. Contacts
    • Present Technologies
    http://www.present-technologies.com
    • Blog
    http://www.samaxes.com
    • Twitter
    http://twitter.com/samaxes
    Present Technologies 35
    

    View Slide