Michael Rimov Centerline Computers Craig McClanahan Sun Microsystems O’Reilly Open Source Convention July 7 - 11, 2003
Michael RimovCenterline Computers
Craig McClanahanSun Microsystems
O’Reilly Open Source ConventionJuly 7 - 11, 2003
Michael Rimov & Craig McClanahan
Introduction
Presentation Slides, Notes and Samples Available At:
http://www.centercomp.com/beyondstruts/
Michael Rimov & Craig McClanahan
What Defines Struts?
• Lightweight Model 2 J2EE framework for the HTTP Servlet portion of the application.
• NOT Meant to dictate the entire J2EE implementation.
Michael Rimov & Craig McClanahan
Model 2 Typical Flow
Controller Model
View
Browser
MVC Based Model 2 Architecture Diagram
Michael Rimov & Craig McClanahan
Abbreviated Model
Controller
View
Model
Michael Rimov & Craig McClanahan
What Makes Struts So Extensible?
• Lightweight and Focused: Doesn’t Try To Do Everything.
• Well Designed: Very good separation of concerns, very clean coding implementation.
• Uses Java Reflection to allow freedom of objects.
Michael Rimov & Craig McClanahan
Case Studies
Michael Rimov & Craig McClanahan
Case Studies
• Struts and Expresso
• Struts and Macromedia Flash• Struts and XML• Struts and Java Server Faces
Michael Rimov & Craig McClanahan
Case Study: Expresso 5http://www.jcorporate.com/
Michael Rimov & Craig McClanahan
Case Study: Expresso 5
Controller
View
Model
ExpressoController
ControllerResponse
DefaultJSP
XSLT
Michael Rimov & Craig McClanahan
Case Study: Expresso 5
Controller Extension:
• Provided Application Level Security Matrix
• Added in-request routing ability.• Provided mostly-Servlet Independent
flow of control.
Michael Rimov & Craig McClanahan
Case Study: Expresso 5
Struts Action:
public ActionForward perform(ActionMapping mapping,ActionForm form,
HttpServletRequest request,
HttpServletResponse response)
Expresso Version:
protected void runPromptLoginState(ControllerRequest request, ControllerResponse response)
Michael Rimov & Craig McClanahan
Case Study: Expresso 5
Model Extension:
• ControllerRequest / ControllerResponse objects.
• ControllerResponse is populated with Inputs/Outputs/Blocks/Transitions.
• Can use Struts Beans as well.• Added Database Access Layer
Michael Rimov & Craig McClanahan
Case Study: Expresso 5
View Extension:
• Default UI Renderer• Customizable XSLT Processing
Capabilities.• Compatible with Struts Views.
Michael Rimov & Craig McClanahan
Case Study: Expresso 5
Integration Experiences:
• Extremely supportive community• Reaped Performance Improvements• Partial Integrations still work well.• Easy to extend even the Struts internals.
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flashhttp://www.macromedia.com/software/flash
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
Controller
View
Model
JSP / Flash
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
Integration Methods:
• XMLSocket and XML formatted pages.• LoadVariables and property formatted
pages.• NOT covering Flash Remoting
All Integration methods need some sort of template view system such as JSP or Velocity.
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
Start Page
• Tell Flash Where To Get Its Data.<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0" width="445" height="244">
<param name="movie" value= “mymovie.swf?data=http://www.example.org/MyAction.do&next=http://www.example.org/NextAction.do">
<param name="quality" value="high">
<embed src= “mymovie.swf?data=http://www.example.org/MyAction.do&next=http://www.example.org/NextAction.do" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave-flash" width="445" height="244"></embed>
</object>
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
XML Socket Method
• Create Flash Starting Page • Load initial data through the ‘data’
parameter. • On-submit, the movie opens an XML
Socket to the server and Struts.• Struts formats return data as XML.
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
XML Socket Method: Drawbacks
• XML Parsing on the Client Side.• XML Parsing on the Server Side• Expansion of Bandwidth
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
Load Variables Method
• Create Flash Starting Page • Load initial data through the ‘data’
parameter. • On-submit, the movie opens an http
request to the server.• Struts formats return data in a
“property=value” format.
Michael Rimov & Craig McClanahan
Case Study: Macromedia Flash
Load Variables Method: Drawbacks
• Simple format of return data only.• Fancier formats require parsing again.
Similar drawbacks as XMLSocket.• Recommended you use simple beans for
rendering only• Flash 6 Only
Michael Rimov & Craig McClanahan
Quick ActionScript Sampleon (release) {
LoadVars lv = new LoadVars();
LoadVars receiveVars = new LoadVars();
lv.loginName=LoginName;
lv.password = Password; receiveVars.onLoad = processResult; //Not Shown Here
lv.sendAndLoad(data,receiveVars,"POST");
}
Michael Rimov & Craig McClanahan
Introducing Craig McClanahan
Michael Rimov & Craig McClanahan
Case Study: Struts and XML
Michael Rimov & Craig McClanahan
Case Study: Struts and XML
• Most Struts apps generate HTML– With the Struts HTML tags (JSP)– With alternative presentation systems like
Velocity and Freemarker
• Templates accessed via RequestDispatcher. forward() call, but there's another way ...
• Action.execute() -- return null to indicate that the response has been created already
• Opens the door to XML-based output
Michael Rimov & Craig McClanahan
Struts and XML: General Approach
• Form submitted to Action, as usual
• Action creates result beans, as usual, or renders XML objects
• Action renders XML directly (or forwards to an XML-generating template)
• Template incorporates dynamic data from result beans or rendered XML objects
• XSLT stylesheet(s) transform to HTML or other markup language
Michael Rimov & Craig McClanahan
Struts and XML: Resources• JSP and JSTL can be used directly instead
of HTML tags
• Two Popular Struts and XML Extensions:– StrutsCX
• Http://it.cappuccinonet.com/strutscx/
– Stxx• http://www.openroad.ca/opencode/
• More information online, on the Struts Resources pages:
• http://jakarta.apache.org/struts/resources/
Michael Rimov & Craig McClanahan
Case Study: Struts and JavaServer Faces
Michael Rimov & Craig McClanahan
Case Study: JavaServer Faces
• What Is JavaServer Faces?– Server-side user interface component
framework for Java-based web apps– Under development in the Java Community
Process (JSR-127)– Currently at Public Draft 2 in the process– Early Access 4 of Reference
Implementation is available– http://java.sun.com/j2ee/javaserverfaces/
Michael Rimov & Craig McClanahan
JavaServer Faces: Goals
• Accessible to corporate developers
• Usable via tools and by hand• Usable with and without JSP• Usable with and without HTML• Usable with servlet and portlet APIs• Can be adopted immediately
– Minimum platform: Servlet 2.3, JSP 1.2– Final 1.0 version: 4QCY2003
Michael Rimov & Craig McClanahan
JavaServer Faces: Features
• Extensible UI component model
• Flexible rendering model– Standard HTML renderkit included
• Event and listener model• Validation framework• Basic page navigation support• Internationalization and accessibility
Michael Rimov & Craig McClanahan
JavaServer Faces: Sample Page<f:use_faces>
<h:form formName=”logonForm”>
<h:panel_grid columns=”2”>
<h:output_text value=”Username:”/>
<h:input_text id=”username” length=”16”
valueRef=”logonBean.username”/>
<h:output_text value=”Password:”/>
<h:input_secret id=”password”
length=”16”
valueRef=”logonBean.password”/>
Michael Rimov & Craig McClanahan
JavaServer Faces: Sample Page <h:command_button type=”submit”
label=”Log On”
actionRef=”logonBean.logon”/>
<h:command_button type=”reset”
label=”Reset”/>
</h:panel_grid>
</h:form>
</f:use_faces>
Michael Rimov & Craig McClanahan
JavaServer Faces: Managed Bean<managed-bean>
<managed-bean-name>
logonBean
</managed-bean-name>
<managed-bean-class>
mypackage.mybeans.LogonBean
</managed-bean-class>
<managed-bean-scope>
request
</managed-bean-scope>
</managed-bean>
Michael Rimov & Craig McClanahan
JavaServer Faces: Bean Classpublic class LogonBean { // No base class!
// The usual property getters/setters
public String getUsername() { ... }
public void setUsername(String username)
{ ... }
public String getPassword() { ... }
public void setPassword(String password)
{ ... }
Michael Rimov & Craig McClanahan
JavaServer Faces: Bean Class ...
// Getter returns “Action” for button
public Action getLogon() {
// Anonymous inner class used here
return new Action() {
public String invoke() {
// Invoke method on bean class
return (logon());
}
};
}
Michael Rimov & Craig McClanahan
JavaServer Faces: Bean Class ...
protected String logon() {
// Business logic can access form fields
// as instance variables
if (username/password combo is ok) {
return (“success”); // Logical outcome
} else {
return (null);
}
}
}
Michael Rimov & Craig McClanahan
JavaServer Faces: Navigation<navigation-rule>
// Wildcard and global patterns ok
<from-tree-id> /logon.jsp </from-tree-id>
<navigation-case>
<from-action-ref> // Optional
logonBean.logon </from-action-ref>
<from-outcome> // Optional
success </from-outcome>
<to-tree-id>
/mainmenu.jsp </to-tree-id>
</navigation-case>
</navigation-rule>
Michael Rimov & Craig McClanahan
JavaServer Faces and Struts
• So, is JavaServer Faces Replacing Struts?– NO!!!– Struts 1.1 is and remains very popular– Struts will continue to innovate & advance
• Then, can I use them together?– YES!!!– With the Struts-Faces Integration Library
• http://jakarta.apache.org/builds/jakarta-struts/
release/struts-faces/
Michael Rimov & Craig McClanahan
JavaServer Faces And Struts
• Replaces Struts HTML Tags With More Powerful JavaServer Faces Components
• Continue to use struts-config.xml file• Integrates with Struts RequestProcessor• Supports Standard Struts Features:
– Form Beans and Actions– Validator Framework– Tiles Framework (coming soon ...)
Michael Rimov & Craig McClanahan
JavaServer Faces and Struts
• To use the library with an existing app:– Get the JavaServer Faces RI– Drop it and struts-faces.jar into your
/WEB-INF/lib directory– Change HTML tags on one page at a time– Tweak your forward paths, and– Don't touch your form beans or actions
• MVC works ... what a concept :-).
Michael Rimov & Craig McClanahan
Conclusion
Michael Rimov & Craig McClanahan
Presentation Information
Michael Rimov: [email protected]
Craig McClanahan:[email protected]
Slides, Notes and Sample Code Availablehttp://www.centercomp.com/beyondstruts/
Michael Rimov & Craig McClanahan