1. A Portal Architecture Review

2. Talk Overview Portal architectures Portal architectures JSR 168 review JSR 168 review A motivating example A motivating example Building grid clients with the Java COG. Building grid clients with the Java COG. Combining the Java COG with Java Server Faces. Combining the Java COG with Java Server Faces.

3. A Famous Web Portal

4. A Famous Portal, After Login

5. What to Notice After logging in, my colors, layouts, and content all changed. After logging in, my colors, layouts, and content all changed. I get my stock list, my Bloomington weather, my news stories, etc.I get my stock list, my Bloomington weather, my news stories, etc. I got rid of “Garfield”I got rid of “Garfield” As we will see later, each of these content fragments (encircled) is managed by a thing called a portlet… As we will see later, each of these content fragments (encircled) is managed by a thing called a portlet… … I don’t guarantee that this is true for Yahoo’s web site but it is true for a large class of enterprise Java portal systems.… I don’t guarantee that this is true for Yahoo’s web site but it is true for a large class of enterprise Java portal systems. Portlets are the key to portal software reuse. Portlets are the key to portal software reuse.

6. Let 10,000 Flowers Bloom Many portal projects have been launched since late ’90s. Many portal projects have been launched since late ’90s. HotPage from SDSC, NCSA efforts, DOD, DOE Portals, NASA IPGHotPage from SDSC, NCSA efforts, DOD, DOE Portals, NASA IPG 2002 Special Issue of Concurrency and Computation: Practice and Experience.2002 Special Issue of Concurrency and Computation: Practice and Experience. The field continues to be active The field continues to be active Global Grid Forum 14 Science Gateway workshop in June 2005.Global Grid Forum 14 Science Gateway workshop in June 2005. About 15 gateways will be described in upcoming issue of Concurrency.About 15 gateways will be described in upcoming issue of Concurrency. GCE2005 workshop at Supercomputing 05.GCE2005 workshop at Supercomputing 05. http://www.ggf.org/ggf_events_lodging_ggf15.htm http://www.ggf.org/ggf_events_lodging_ggf15.htm How do we share and reuse all of this work? How do we share and reuse all of this work?

7. Portal User Interface Grid Resource Broker Service Grid and Web Protocols Information and Data Services Database Service Database HPC or Compute Cluster Grid Information Services, SRB Portal Client Stub Portal Client Stub Portal Client Stub JDBC, Local, or Remote Connection Three-Tiered Architecture Three-tiered architecture is accepted standard for accessing Grid and other services

8. JSR 168 Overview Java Portlet Stadard

9. What Is a Portlet? A portlet is a piece of Java code that manages the content of one section of a web portal’s HTML. A portlet is a piece of Java code that manages the content of one section of a web portal’s HTML. It can do anything else that a Java web application can do. It can do anything else that a Java web application can do. You can connect a portlet to a database, invoke a web service, download an RSS feed, etc.You can connect a portlet to a database, invoke a web service, download an RSS feed, etc. It lives in a portlet container, which creates, manages, and destroys all the portlets of the portal. It lives in a portlet container, which creates, manages, and destroys all the portlets of the portal. Portlet containers are part of portals. Portlet containers are part of portals. Portals must do other things like manage login, users, groups, layouts, etc.Portals must do other things like manage login, users, groups, layouts, etc. JSR 168 standardizes two main things: JSR 168 standardizes two main things: How the portlet container manages portlet lifecyclesHow the portlet container manages portlet lifecycles How the portlets are programmed.How the portlets are programmed.

10. What is JSR 168? From the portlet development point of view, it is really very simple: From the portlet development point of view, it is really very simple: You write a java class that extends GenericPortlet.You write a java class that extends GenericPortlet. You override/implement several methods inherited from GenericPortlet.You override/implement several methods inherited from GenericPortlet. You use some supporting classes/interfacesYou use some supporting classes/interfaces Many are analogous to their servlet equivalents Many are analogous to their servlet equivalents Some (portletsession) actually seem to be trivial wrappers around servlet equivalents in Pluto. Some (portletsession) actually seem to be trivial wrappers around servlet equivalents in Pluto. I have a complete example in the extended slides. I have a complete example in the extended slides. See also tutorial slides.See also tutorial slides.

11. Some Open Source JSR 168 Containers GridSphere GridSphere http://www.gridsphere.orghttp://www.gridsphere.orghttp://www.gridsphere.org uPortal uPortal http://www.uportal.orghttp://www.uportal.orghttp://www.uportal.org LifeRay LifeRay http://sourceforge.net/projects/lportalhttp://sourceforge.net/projects/lportalhttp://sourceforge.net/projects/lportal eXo platform eXo platform http://www.exoplatform.comhttp://www.exoplatform.comhttp://www.exoplatform.com StringBeans StringBeans http://www.nabh.com/projects/sbportalhttp://www.nabh.com/projects/sbportal Jetspeed2 Jetspeed2 http://portals.apache.org/jetspeed-2/http://portals.apache.org/jetspeed-2/http://portals.apache.org/jetspeed-2/

12. Some GenericPortlet.java Methods MethodDescription Init Called when the portlet is created. Override if you need to set initial params. doView Controls what happens immediately before the portlet is displayed in view mode. Normally you override this. doHelp, doEdit Other portlet display modes processAction Place for handling any actions before turning over to the display mode method (like doView). You should override this for web forms.

13. Some Supporting Classes/Interfaces ClassDescription PortletContext Similar to servlet context; get context info and the RequestDispatcher from here. PortletSession Stores attribute information for a single portlet application across multiple requests. RenderRequest, RenderResponse The request and response objects available to the doView() method. Similar to the normal servlet request ActionRequest,Actio nResponse The request and response objects available to the processAction() method. Similar to the servlet request and response objects. PortletURL Use this to create URLs that reference the portal. PortletRequestDispa tcher Use this to include/forward to a JSP or servlet in the same portlet app. WindowState See if you are in minimized, maximized, normal state.

14. The Big Picture As a portlet developer, the previous set of classes are all you normally touch. As a portlet developer, the previous set of classes are all you normally touch. The portlet container (Pluto) is responsible for running your portlets. The portlet container (Pluto) is responsible for running your portlets. Init, invoke methods, destroy.Init, invoke methods, destroy. Portlets have a very limited way of interacting with the container. Portlets have a very limited way of interacting with the container. The API is basically one-way.The API is basically one-way.

15. A Comment on Portlet Coding JSR 168 seems to make some important and dubious assumptions JSR 168 seems to make some important and dubious assumptions Developers will gladly ignore other development methodologies/frameworks like Velocity, Struts, and Java Server Faces.Developers will gladly ignore other development methodologies/frameworks like Velocity, Struts, and Java Server Faces. Developers instead want to write a GenericPortlet extension for every single portlet they develop.Developers instead want to write a GenericPortlet extension for every single portlet they develop. And write really complicated processAction() and doView() methods. And write really complicated processAction() and doView() methods. Developers will like the specific JSR 168 portlet-style Model-View-Controller that it forces on them.Developers will like the specific JSR 168 portlet-style Model-View-Controller that it forces on them. Fortunately, these other development environments can be mapped to portlet actions. Fortunately, these other development environments can be mapped to portlet actions. In the OGCE project, we have developed support for Velocity portlets.In the OGCE project, we have developed support for Velocity portlets. We are transitioning to Java Server FacesWe are transitioning to Java Server Faces

16. A Grid Portlet Scenario Developing a Simple Grid Portlet Application

17. A Quantum Chemistry Code Submission Form You have been asked to develop a submission form for the Democritos group’s Quantum Espresso (QE) package. You have been asked to develop a submission form for the Democritos group’s Quantum Espresso (QE) package. These forms should help users set up and run QE applications on the TeraGrid and other Grid installations. These forms should help users set up and run QE applications on the TeraGrid and other Grid installations. Mix of GT 2, GT 4, Condor, etc., for submissionMix of GT 2, GT 4, Condor, etc., for submission You are told to initially support the Plane Wave Self Consistent Field (PWSCF) code. You are told to initially support the Plane Wave Self Consistent Field (PWSCF) code. Other QE applications may follow. Other QE applications may follow. These may be coupled with PWSCF into simple workflows, but this is a later problem.These may be coupled with PWSCF into simple workflows, but this is a later problem.

18. Your Deployment Architecture Portal Server @FSU GT 4 @TG MSI PBS GT 2 @UMN TeraGrid LSF Your portal server runs at FSU. It acts as a common Gateway to different grid toolkit installations and resources

19. Some Issues You decide the JSR 168 style portlets are the way to go… You decide the JSR 168 style portlets are the way to go… But of course the PWSCF portlet doesn’t exist yet.But of course the PWSCF portlet doesn’t exist yet. You will need to also support other Quantum Espresso codes. You will need to also support other Quantum Espresso codes. Would like to reuse as much code as possible.Would like to reuse as much code as possible. But your PWSCF portlet isn’t reusable at that level.But your PWSCF portlet isn’t reusable at that level. You also would like to simplify saving user input data and session archiving. You also would like to simplify saving user input data and session archiving.

20. PWSCF Web Forms for Submission

21. Your Choices JSR 168 will allow you to share your portlet code with other collaborators. JSR 168 will allow you to share your portlet code with other collaborators. The Java COG Kit will help hide the differences between Grid toolkits for common tasks. The Java COG Kit will help hide the differences between Grid toolkits for common tasks. Vanilla JSF will help simplify your portlet development in several ways. Vanilla JSF will help simplify your portlet development in several ways. JSF decouples your backing code from the Servlet APIJSF decouples your backing code from the Servlet API You can write your backing code as pure Java Beans/Plain Old Java Objects. You can write your backing code as pure Java Beans/Plain Old Java Objects. You don’t have to adopt, maintain HTTP parameter name conventions. You don’t have to adopt, maintain HTTP parameter name conventions. Your form input backing beans can be serialized/deserialized with Castor.Your form input backing beans can be serialized/deserialized with Castor. Coupling JSF and COG will allow you to compose your Grid actions using simple JSF taglibs. Coupling JSF and COG will allow you to compose your Grid actions using simple JSF taglibs. You can reuse your Grid taglibs in other Quantum Espresso portlets.You can reuse your Grid taglibs in other Quantum Espresso portlets. You can compose composite actionsYou can compose composite actions

22. The Java CoG Kit Gregor von Laszewski Argonne National Laboratory University of Chicago gregor@mcs.anl.gov http://www.cogkit.org (as interpreted by MEP)

23. CoG Kits CoG Kits make Grid programming simple and new technologies are easy to integrate CoG Kits make Grid programming simple and new technologies are easy to integrate We focus on a CoG Kit for Java We focus on a CoG Kit for Java Python also available (K. Jackson, LBNL)Python also available (K. Jackson, LBNL) Availability: Java CoG Kit since 1997Availability: Java CoG Kit since 1997 The CoG provides two important things The CoG provides two important things A higher level client programming environment than stubs.A higher level client programming environment than stubs. A shield against different versions of the Globus toolkitA shield against different versions of the Globus toolkit Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0, GT 3.2.1, GT 4.0.0 Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0, GT 3.2.1, GT 4.0.0

24. CoG Abstraction Layer CoG CoG Data and Task Management Layer CoG Gridfaces Layer CoG CoG GridIDE GT2 GT3 OGSI classic GT4 WS-RF CondorUnicore Applications SSH Others Avaki SETI Nano materials Bio- Informatics Disaster Management Portals CoG Abstraction Layer CoG CoG Data and Task Management Layer CoG Gridfaces Layer CoG CoG GridIDE Development Support CoG Abstraction Layers

25. Task Handler Service Task Specification Security Context Service Contact The class diagram is the same for all grid tasks (running jobs, modifying files, moving data). Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc.

26. Java COG Summary The Java COG 4 interfaces provide high level abstractions for building Grid clients. The Java COG 4 interfaces provide high level abstractions for building Grid clients. Abstract out differences between Grid toolkits.Abstract out differences between Grid toolkits. Provide task abstractions that form the basis for constructing DAG-style, file-based workflow.Provide task abstractions that form the basis for constructing DAG-style, file-based workflow. The COG can be used to build a wide range of clients The COG can be used to build a wide range of clients Desktops, grid shells, and of course portals.Desktops, grid shells, and of course portals. Portlets are a well known way to build reusable portal components.Portlets are a well known way to build reusable portal components.

27. Building Grid Portlets with Java Server Faces

28. Limitations of Portlets Portlets provide a way to bundle and share a complete application. Portlets provide a way to bundle and share a complete application. RSS portlet, GridFTP portlet, SRB portlet, etc.RSS portlet, GridFTP portlet, SRB portlet, etc. Portlets combine the user interface view and action code.Portlets combine the user interface view and action code. But in science gateway development, we often need finer grained components. But in science gateway development, we often need finer grained components. “When user clicks button, upload file, launch code, and move data someplace when done.”“When user clicks button, upload file, launch code, and move data someplace when done.” Combines “GridFTP” and “Job Submit” portlets…Combines “GridFTP” and “Job Submit” portlets… Or maybe OGSA-DAI or SRB or ….Or maybe OGSA-DAI or SRB or …. We need a way for the view and action code must be developed from reusable parts. We need a way for the view and action code must be developed from reusable parts.

29. JSF and Science Gateways JSF enables you back your science application input form portlets with Java Beans. JSF enables you back your science application input form portlets with Java Beans. Again, these are independent of the servlet container, so are easy to test and to reuse in other applications.Again, these are independent of the servlet container, so are easy to test and to reuse in other applications. But also, Java Beans can be easily serialized with XML. But also, Java Beans can be easily serialized with XML. Castor, XML BeansCastor, XML Beans Marshal and un-marshal user input for persistent storage in XML storage servicesMarshal and un-marshal user input for persistent storage in XML storage services OGSA-DAI, GPIR, WS-Context OGSA-DAI, GPIR, WS-Context Potentially, can develop backing code as XML Schema and generate the code.Potentially, can develop backing code as XML Schema and generate the code.

30. JSF for Grid Enabled HTML Widgets Natural program: develop Java Bean wrappers around Java COG kit, OGSA-DAI client API, SRB Jargon, etc. Natural program: develop Java Bean wrappers around Java COG kit, OGSA-DAI client API, SRB Jargon, etc. Allows simple integration with JSF.Allows simple integration with JSF. Some issues exist Some issues exist JSF only manages individual bean instances.JSF only manages individual bean instances. But grid portlets will need to manage an unknown number of bean instances.But grid portlets will need to manage an unknown number of bean instances. You may launch and monitor many different jobs. You may launch and monitor many different jobs. We need a way of scripting composite actions created out of multiple reusable actions.We need a way of scripting composite actions created out of multiple reusable actions.

31. COG Bean Wrappers Recall the COG structure Recall the COG structure Executable tasks abstract basic grid actions and hide toolkit version differences.Executable tasks abstract basic grid actions and hide toolkit version differences. These tasks can be collected into file- based DAG workflows.These tasks can be collected into file- based DAG workflows. First problem is simple: wrap tasks as beans to make them available to JSF. First problem is simple: wrap tasks as beans to make them available to JSF. GenericGridBean defines the interfaceGenericGridBean defines the interface Second problem is managing multiple individual tasks. Second problem is managing multiple individual tasks.

32. Managing Multiple Grid Tasks We must create and manage multiple beans for each task. We must create and manage multiple beans for each task. That is, I submit the job four times in one session.That is, I submit the job four times in one session. Similarly, we can create multiple task graph clones.Similarly, we can create multiple task graph clones. We do this by cloning and storing each bean. We do this by cloning and storing each bean. Beans have listeners and maintain state. Beans have listeners and maintain state. Unsubmitted, submitted, active, suspended, resumed are “live”Unsubmitted, submitted, active, suspended, resumed are “live” Stored in live repository Stored in live repository Failed, canceled, completed, unknown are “dead”Failed, canceled, completed, unknown are “dead” Stored in archive (WS-Context or other) Stored in archive (WS-Context or other) Alternative approach: use one bean that is a bean factory for GenericGridTask beans. Alternative approach: use one bean that is a bean factory for GenericGridTask beans.

33. Task Submission Form Corresponding JSF snippets

34. Task Monitoring with JSF Data Model Corresponding Java class. public class Job { private String jobId; private String status; private String submitDate; private String finishDate; }

35. Extended Slides

36. The Java CoG Kit Gregor von Laszewski Argonne National Laboratory University of Chicago gregor@mcs.anl.gov http://www.cogkit.org (as interpreted by MEP)

37. CoG Kits CoG Kits make Grid programming simple and new technologies are easy to integrate CoG Kits make Grid programming simple and new technologies are easy to integrate We focus on a CoG Kit for Java We focus on a CoG Kit for Java Python also available (K. Jackson, LBNL)Python also available (K. Jackson, LBNL) Availability: Java CoG Kit since 1997Availability: Java CoG Kit since 1997 The CoG provides two important things The CoG provides two important things A higher level client programming environment than stubs.A higher level client programming environment than stubs. A shield against different versions of the Globus toolkitA shield against different versions of the Globus toolkit Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0, GT 3.2.1, GT 4.0.0 Same high level API works with GT 2.4, GT 3.0.2, GT 3.2.0, GT 3.2.1, GT 4.0.0

38. CoG Abstraction Layer CoG CoG Data and Task Management Layer CoG Gridfaces Layer CoG CoG GridIDE GT2 GT3 OGSI classic GT4 WS-RF CondorUnicore Applications SSH Others Avaki SETI Nano materials Bio- Informatics Disaster Management Portals CoG Abstraction Layer CoG CoG Data and Task Management Layer CoG Gridfaces Layer CoG CoG GridIDE Development Support CoG Abstraction Layers

40. Task Handler Service Task Specification Security Context Service Contact The class diagram is the same for all grid tasks (running jobs, modifying files, moving data). Classes also abstract toolkit provider differences. You set these as parameters: GT2, GT4, etc.

41. Setting Up Task and Specification Task task=new TaskImpl(“mytask”, Task.JOB_SUBMISSION);task.setProvider(“GT2”); JobSpecification spec= new JobSpecificationImpl(); spec.setExecutable(“rm”);spec.setBatchJob(true);spec.setArguments(“-r”);…task.setSpecification(spec);

42. Setting Up the Service and Security Context Service service=new ServiceImpl(Service.JOB_SUBMISSION); service.setProvider(“GT2”); SecurityContext securityContext= CoreFactory.newSecurityContext(“GT2”); //Use cred object from ProxyManager securityContext.setCredentials(cred);service.setSecurityContext((SecurityContext)securityContext);

43. Set Up Service Contact and Finish ServiceContact serviceContact= new ServiceContact(“myhost.myorg.org”); service.setServiceContact(serviceContact);task.setService(Service.JOB_SUBMISSION_SERVICE,service); TaskHandler handler=new GenericTaskHandler(); handler.submit(task);

44. Coupling CoG Tasks The COG abstractions also simplify creating coupled tasks. The COG abstractions also simplify creating coupled tasks. Tasks can be assembled into task graphs with dependencies. Tasks can be assembled into task graphs with dependencies. “Do Task B after successful Task A”“Do Task B after successful Task A” Graphs can be nested. Graphs can be nested.

45. Java COG Summary The Java COG 4 interfaces provide high level abstractions for building Grid clients. The Java COG 4 interfaces provide high level abstractions for building Grid clients. Abstract out differences between Grid toolkits.Abstract out differences between Grid toolkits. Provide task abstractions that form the basis for constructing DAG-style, file-based workflow.Provide task abstractions that form the basis for constructing DAG-style, file-based workflow. The COG can be used to build a wide range of clients The COG can be used to build a wide range of clients Desktops, grid shells, and of course portals.Desktops, grid shells, and of course portals. Portlets are a well known way to build reusable portal components.Portlets are a well known way to build reusable portal components.

46. Building Grid Portlets with Java Server Faces

47. Limitations of Portlets Portlets provide a way to bundle and share a complete application. Portlets provide a way to bundle and share a complete application. RSS portlet, GridFTP portlet, SRB portlet, etc.RSS portlet, GridFTP portlet, SRB portlet, etc. Portlets combine the user interface view and action code.Portlets combine the user interface view and action code. But in science gateway development, we often need finer grained components. But in science gateway development, we often need finer grained components. “When user clicks button, upload file, launch code, and move data someplace when done.”“When user clicks button, upload file, launch code, and move data someplace when done.” Combines “GridFTP” and “Job Submit” portlets…Combines “GridFTP” and “Job Submit” portlets… Or maybe OGSA-DAI or SRB or ….Or maybe OGSA-DAI or SRB or …. We need a way for the view and action code must be developed from reusable parts. We need a way for the view and action code must be developed from reusable parts.

48. PWSCF Web Forms for Submission

49. Java Server Faces Overview JSF can solve the reusable portlet widget problem. JSF can solve the reusable portlet widget problem. JSF can also work in “standalone” mode outside of portlets.JSF can also work in “standalone” mode outside of portlets. Potentially independent of Web applications.Potentially independent of Web applications. XUL and Swing widget bindings XUL and Swing widget bindings We will first examine JSF generally We will first examine JSF generally Conclude with integrating JSF and COG Conclude with integrating JSF and COG

50. Advantages of JSF JSF hides communication details that connect HTML forms with backing code. JSF hides communication details that connect HTML forms with backing code. You don’t have to worry about servlet specific request, response, and session objects.You don’t have to worry about servlet specific request, response, and session objects. You don’t have to maintain fragile naming conventions for tags.You don’t have to maintain fragile naming conventions for tags. Developers only need to develop JavaBeans and tag libraries. Developers only need to develop JavaBeans and tag libraries. Beans are independent of Web applications.Beans are independent of Web applications. Can be easily written and tested outside of servlet containers.Can be easily written and tested outside of servlet containers. Compatible popular “Inversion of Control” based systems like JSF and SpringCompatible popular “Inversion of Control” based systems like JSF and Spring

51. JSF and Science Gateways JSF enables you back your science application input form portlets with Java Beans. JSF enables you back your science application input form portlets with Java Beans. Again, these are independent of the servlet container, so are easy to test and to reuse in other applications.Again, these are independent of the servlet container, so are easy to test and to reuse in other applications. But also, Java Beans can be easily serialized with XML. But also, Java Beans can be easily serialized with XML. Castor, XML BeansCastor, XML Beans Marshal and un-marshal user input for persistent storage in XML storage servicesMarshal and un-marshal user input for persistent storage in XML storage services OGSA-DAI, GPIR, WS-Context OGSA-DAI, GPIR, WS-Context Potentially, can develop backing code as XML Schema and generate the code.Potentially, can develop backing code as XML Schema and generate the code.

52. A JSF Example <HTML> Hello Hello Enter some text in the form below Enter some text in the form below <h:inputText id="userSt" <h:inputText id="userSt"value="#{multiEventBean.userString}"/> <h:commandButton id="submit" <h:commandButton id="submit" action="success" value="Submit" > </HTML>

53. The JSF Page Note everything with or namespace prefix is a JSF tag. Note everything with or namespace prefix is a JSF tag. Usually, tags mimic HTML widgets.Usually, tags mimic HTML widgets. is for non-rendered stuff. is for non-rendered stuff. Everything else is good old HTML.Everything else is good old HTML. There are three different Java classes here. There are three different Java classes here. They are all in the package multiEventTestThey are all in the package multiEventTest multiEventBean.java is just a bean with typical get/set methods.multiEventBean.java is just a bean with typical get/set methods. Listener1.java and Listener2.java implement the javax.faces.event.ActionListener interface.Listener1.java and Listener2.java implement the javax.faces.event.ActionListener interface. All 3 classes are called when you click the command button. All 3 classes are called when you click the command button. Also, take a look at. This is roughly equivalent to. Also, take a look at. This is roughly equivalent to. But no name needed. JSF handles parameter names for you and connects them to the beans you specify.But no name needed. JSF handles parameter names for you and connects them to the beans you specify. This greatly simplifies writing generic actions.This greatly simplifies writing generic actions.

54. A Simple Example: HtmlDataGrid <f:view> This shows an example of how to use This shows an example of how to use HtmlDataTable to display some results. HtmlDataTable to display some results. </f:view>

55. It Looks Like This

56. Some Explanation The binds to a particular data set with value=“ValueBean.itemList”. The binds to a particular data set with value=“ValueBean.itemList”. ValueBean.itemList must be java.util.List, java.sql.ResultSet or similar.ValueBean.itemList must be java.util.List, java.sql.ResultSet or similar. The values of these lists may be beans also.The values of these lists may be beans also. The var=“” just defines a useful internal value. The var=“” just defines a useful internal value. Here, each entry in the list is set equal to “values”.Here, each entry in the list is set equal to “values”. In the example, the items in the list happen to be simple beans with member variables “value1” and “value2” along with appropriate getter/setters.In the example, the items in the list happen to be simple beans with member variables “value1” and “value2” along with appropriate getter/setters. When you load the page, it just iterates through the entries in ValueBean.itemList and creates the table, as you instructed. When you load the page, it just iterates through the entries in ValueBean.itemList and creates the table, as you instructed. Note again there are no loops in the actual page. Also, you don’t know anything about the data you are getting. Note again there are no loops in the actual page. Also, you don’t know anything about the data you are getting.

57. JSF Magic: Data Models The M in MVC is the Data Model The M in MVC is the Data Model “Abstract” representation of a data structure“Abstract” representation of a data structure That is, not tied to the display of the data (“view”) That is, not tied to the display of the data (“view”) JSF DataModel extension classes include JSF DataModel extension classes include Arrays: wrap arrays of Java objectsArrays: wrap arrays of Java objects Lists: wraps a java.util.List of Java objectsLists: wraps a java.util.List of Java objects Results: for JSTL’s Result object, which itself wraps SQL ResultSets.Results: for JSTL’s Result object, which itself wraps SQL ResultSets. ResultSets: also for JDBC, wraps the ResultsSet object directly.ResultSets: also for JDBC, wraps the ResultsSet object directly. Scalar: Wraps an individual Java object.Scalar: Wraps an individual Java object. Typically, these should follow Bean patterns for naming member data and their associated getter/setters. Typically, these should follow Bean patterns for naming member data and their associated getter/setters. You can write your own specialized Data Models. You can write your own specialized Data Models. XMLDataModel, for wrapping an XML data bean, comes to mind.XMLDataModel, for wrapping an XML data bean, comes to mind. RSSDataModel is another that I found.RSSDataModel is another that I found. These are associated with UIData classes in the JSF page for display. These are associated with UIData classes in the JSF page for display. HtmlDataTable is an example.HtmlDataTable is an example.

58. JSF Form Validators The user interface stuff ( and ) has lots of built-in validators The user interface stuff ( and ) has lots of built-in validators Verify that input entries are integers, doubles, etc.Verify that input entries are integers, doubles, etc. Verify that input entries fall within the correct range (1 to 10 in the guessNumber example).Verify that input entries fall within the correct range (1 to 10 in the guessNumber example). Verify the string has the right length.Verify the string has the right length. You can extend to write your own specialized validators You can extend to write your own specialized validators

59. Integrating JSF and COG 4 Mehmet Nacar and Marlon Pierce

60. JSF for Grid Enabled HTML Widgets Natural program: develop Java Bean wrappers around Java COG kit, OGSA-DAI client API, SRB Jargon, etc. –Allows simple integration with JSF. Some issues exist –JSF only manages individual bean instances. –But grid portlets will need to manage an unknown number of bean instances. You may launch and monitor many different jobs. –We need a way of scripting composite actions created out of multiple reusable actions.

61. COG Bean Wrappers Recall the COG structure –Executable tasks abstract basic grid actions and hide toolkit version differences. –These tasks can be collected into file-based DAG workflows. First problem is simple: wrap tasks as beans to make them available to JSF. –GenericGridBean defines the interface Second problem is managing multiple individual tasks.

62. JSF Task Management Class Structure

63. Managing Multiple Grid Tasks We must create and manage multiple beans for each task. –That is, I submit the job four times in one session. –Similarly, we can create multiple task graph clones. We do this by cloning and storing each bean. Beans have listeners and maintain state. –Unsubmitted, submitted, active, suspended, resumed are “live” Stored in live repository –Failed, canceled, completed, unknown are “dead” Stored in archive (WS-Context or other) Alternative approach: use one bean that is a bean factory for GenericGridTask beans.

64. Managing Multiple Tasks

65. Creating Task Graphs COG Task Graphs correspond to composite JSF Web Form actions. –Do X, Y, and then Z when user clicks the button. Each of these actions may be reused, but the entire action is new. We must do two things –Wrap the COG TaskGraphHandler with a bean and bean manager. –Provide tag bindings for defining the custom actions.

66. Constructing Task Graphs

67. Task Submission Form Corresponding JSF snippets

68. Task Monitoring with JSF Data Model Corresponding Java class. public class Job { private String jobId; private String status; private String submitDate; private String finishDate; }

69. Expressing Task Graphs with Tags ………