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JDeveloper 10g and JavaServer Faces: High-Performance UIs on the Web Avrom Roy-Faderman Senior Programmer May, 2006 Agenda • A Brief History of Java Web Apps • JavaServer Faces • ADF Faces • Q&A A Brief History of Java Web Apps • Productivity and Maintainability • Capabilities and Performance Servlets • Java classes executed on the server in response to HTTP requests • Originally used to output HTML This use required extensive and awkward Java coding JSP Model 1 • Files closely resembling HTML except for: Some specialized tags “Scriptlets” – embedded bits of Java code • Compiled into Servlets HTML portions outputted directly into generated HTML Specialized tags run bits of Java Scriptlets run directly Problems with JSP Model 1 • Hard to Change Page Flow • Mix of Java (sometimes extensive Java) and Tags on Same Page Model 2 Architectures • Separate out “View” and “Controller” View renders UI Controller handles page flow and responds to user requests • No hardcoded links in view • Generally no procedural code in view A Brief History of Java Web Apps • Productivity and Maintainability • Capabilities and Performance “Thick Client” vs. Web: The Past Requires customized client Large downloads High-interactivity High-performance Runs in unmodified web browser Small downloads Low-interactivity Low-performance Server Server “Web 2.0” • Still run in unmodified browser • Relatively small download size • Much more interactive than traditional web apps • Much higher-performance than traditional web apps Agenda • A Brief History of Java Web Apps • JavaServer Faces • ADF Faces • Q&A JavaServer Faces • The J2EE standard Model 2 Web Applicaton Architecture • Special tag libraries for JSPs/JSPX documents Html Core • Separate controller JavaServer Faces • JSF JSP and Components • Page Flow • Managed Beans Simple JSF JSP Code <body> <h:form> <h:selectOneMenu id="color" required="true"> <f:selectItem itemLabel="Red" itemValue="red" /> <f:selectItem itemLabel="Green" itemValue="green" /> </h:selectOneMenu> </h:form> </body> JSF JSP/JSPX and the Component Palette JavaServer Faces • JSF JSP and Components • Page Flow • Managed Beans The JSF Controller: Page Flow • All page flow information mainained in faces-config.xml • JDeveloper has graphical representations of page flow JSF Page Flow and the Component Palette JSF Navigation Cases • Navigation cases referenced in JSF JSP/JSPX pages • Converted into destination by controller <h:commandLink action="goHome"> Go home! </h:commandLink> JavaServer Faces • JSF JSP and Components • Page Flow • Managed Beans Managed Beans • The JSF Controller can be configured to automatically create and manage Java objects • Controller or view can access “managed properties” on these objects • Scoping: Application Session Request Accessing Managed Properties: JSP • “JSP Expression Language” Syntax: #{beanName.propertyName} Can even have nested properties: #{beanName.property1.property2} • Use these expressions as attributes for tags <h:outputText value="#{homeBean.mainLabel} /> Managed Bean Classes • Each managed bean has a class that you can edit Constructor runs at the beginning of the application/request/session Methods that allow you to access managed properties • Put complex logic in here instead of putting it in the view Managed Bean Example <h:outputText value="#{homeBean.mainLabel} /> public class NavigationBean { public NavigationBean() { if /* some condition */ { setMainLabel("Red"); } else { setMainLabel("Green"); } } /* … */ } Conditional Page Flow • Instead of referring to a JSF navigation case, refer to a function that *returns* one. <h:commandLink action="#{homeBean.nextAction}"> Go on! </h:commandLink> public String nextAction() { if /* some condition */ { return("goStatus"); } else { return("goOrder"); } } Agenda • A Brief History of Java Web Apps • JavaServer Faces • ADF Faces • Q&A ADF Faces • Oracle ADF • The ADF Binding Filter • Partial Page Refresh ADF and MVC • Oracle ADF is a framework based on MVC architecture View and Controller (Desktop Clients) View (Web and Wireless Clients) Controller (Web and Wireless Clients) Model Business Services ADF and MVC • Oracle ADF is a framework based on MVC architecture ADF Swing ADF Faces Components ADF Binding Filter ADF Data Bindings ADF Business Components ADF Faces • Oracle ADF • The ADF Binding Filter • Partial Page Refresh ADF Binding Filter • Runs with each HTTP request • Sets up a Struts managed bean, “bindings”, containing all ADF data bindings <af:inputText value="#{bindings.EmpName.inputValue} /> ADF Data Bindings Database Business Service The Data Control Palette ADF Faces • Oracle ADF • The ADF Binding Filter • Partial Page Refresh Traditional “Web 1.0 Cycle” Request submitted to server Server renders page Page downloaded to user User clicks button or link User fills out form Component Trees • You can think of a JSP/JSPX document as being a tree of components <afh:body> <af:form> <af:selectOneMenu id="color" required="true"> <af:selectItem itemLabel="Red" itemValue="red" /> <af:selectItem itemLabel="Green" itemValue="green" /> </af:selectOneMenu> </af:form> </afh:body> Partial Page Refresh • Use Javascript to submit a form at times other than when a user presses a button or link • On server, re-render only a portion of component tree • Download only the appropriate fragment of HTML Partial Page Refresh—How It Works Server Web Cycle with PPR Request submitted to server Server renders components User manipulates component Components downloaded to user ADF Faces and PPR • Many components always use PPR Table sorting Table pagination Expandable tables and menus … • Almost all components can use PPR Requires some manual work Simple PPR Example <af:inputText id="myTextField" autoSubmit="true" partialSubmit="true" /> ... <af:outputText id="myTextOutput" value="#{homeBean.calculatedVal}" partialTriggers="myTextField" /> A Few Words about AJAX Asynchronous Javascript And XML • PPR is an important part of “Web 2.0” But PPR, by itself, isn’t truly asynchronous ADF Faces (and regular JSF) “supports” full AJAX, but really only in that it supports Javascript Q&A