Download A Portal Architecture Review

A Portal Architecture
Review
Talk Overview





Portal architectures
JSR 168 review
A motivating example
Building grid clients with the Java
COG.
Combining the Java COG with Java
Server Faces.
A Famous Web Portal
A Famous Portal, After Login
What to Notice

After logging in, my colors, layouts, and
content all changed.
• I get my stock list, my Bloomington weather, my
news stories, etc.
• I got rid of “Garfield”

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.

Portlets are the key to portal software reuse.
Let 10,000 Flowers Bloom

Many portal projects have been launched
since late ’90s.
• HotPage from SDSC, NCSA efforts, DOD, DOE
Portals, NASA IPG
• 2002 Special Issue of Concurrency and
Computation: Practice and Experience.

The field continues to be active
• Global Grid Forum 14 Science Gateway workshop
in June 2005.
• About 15 gateways will be described in upcoming
issue of Concurrency.
• GCE2005 workshop at Supercomputing 05.


http://www.ggf.org/ggf_events_lodging_ggf15.htm
How do we share and reuse all of this work?
Three-Tiered Architecture
Portal User Interface
Grid and
Web
Protocols
JDBC,
Local, or
Remote
Connection
Portal
Client
Stub
Database
Service
Database
Portal
Client
Stub
Grid Resource
Broker Service
HPC
or
Compute Cluster
Portal
Client
Stub
Information
and
Data Services
Grid Information
Services, SRB
Three-tiered architecture is accepted standard for
accessing Grid and other services
JSR 168 Overview
Java Portlet Stadard
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.
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.


It lives in a portlet container, which creates,
manages, and destroys all the portlets of the portal.
Portlet containers are part of portals.
• Portals must do other things like manage login, users,
groups, layouts, etc.

JSR 168 standardizes two main things:
• How the portlet container manages portlet lifecycles
• How the portlets are programmed.
What is JSR 168?

From the portlet development point of view,
it is really very simple:
• You write a java class that extends
GenericPortlet.
• You override/implement several methods
inherited from GenericPortlet.
• You use some supporting classes/interfaces



Many are analogous to their servlet equivalents
Some (portletsession) actually seem to be trivial
wrappers around servlet equivalents in Pluto.
I have a complete example in the extended
slides.
• See also tutorial slides.
Some Open Source JSR 168
Containers

GridSphere
• http://www.gridsphere.org

uPortal
• http://www.uportal.org

LifeRay
• http://sourceforge.net/projects/lportal

eXo platform
• http://www.exoplatform.com

StringBeans
• http://www.nabh.com/projects/sbportal

Jetspeed2
• http://portals.apache.org/jetspeed-2/
Some GenericPortlet.java Methods
Method
Description
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 <form> actions
before turning over to the display mode
method (like doView). You should override
this for web forms.
Some Supporting Classes/Interfaces
Class
Description
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.
The Big Picture
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
As a portlet developer, the previous set of classes are all you
normally touch.
The portlet container (Pluto) is responsible for running your
portlets.
• Init, invoke methods, destroy.

Portlets have a very limited way of interacting with the
container.
• The API is basically one-way.
A Comment on Portlet Coding

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 instead want to write a GenericPortlet extension
for every single portlet they develop.

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.

Fortunately, these other development environments
can be mapped to portlet actions.
• In the OGCE project, we have developed support for
Velocity portlets.
• We are transitioning to Java Server Faces
A Grid Portlet Scenario
Developing a Simple Grid
Portlet Application
A Quantum Chemistry Code
Submission Form


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.
• Mix of GT 2, GT 4, Condor, etc., for submission


You are told to initially support the Plane
Wave Self Consistent Field (PWSCF) code.
Other QE applications may follow.
• These may be coupled with PWSCF into simple
workflows, but this is a later problem.
Your Deployment Architecture
Your portal
server runs
at FSU.
It acts as a common Gateway to
different grid toolkit
installations and resources
GT 4
@TG
TeraGrid
LSF
GT 2
@UMN
MSI
PBS
Portal
Server
@FSU
Some Issues

You decide the JSR 168 style portlets are
the way to go…
• But of course the PWSCF portlet doesn’t exist
yet.

You will need to also support other
Quantum Espresso codes.
• Would like to reuse as much code as possible.
• But your PWSCF portlet isn’t reusable at that
level.

You also would like to simplify saving user
input data and session archiving.
PWSCF Web Forms for
Submission
Your Choices



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.
Vanilla JSF will help simplify your portlet
development in several ways.
• JSF decouples your backing code from the Servlet API


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.
• 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.
• You can reuse your Grid taglibs in other Quantum Espresso
portlets.
• You can compose composite actions
The Java CoG Kit
Gregor von Laszewski
Argonne National Laboratory
University of Chicago
[email protected]
http://www.cogkit.org
(as interpreted by MEP)
CoG Kits


CoG Kits make Grid programming simple and
new technologies are easy to integrate
We focus on a CoG Kit for Java
• Python also available (K. Jackson, LBNL)
• Availability: Java CoG Kit since 1997

The CoG provides two important things
• A higher level client programming environment
than stubs.
• A 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
CoG Abstraction Layers
Nano
materials
BioDisaster
Informatics
Management
Applications
Portals
Development
Support
CoGGridfaces
GridfacesLayer
Layer
CoG
CoG
CoG GridIDE
GridIDE
CoGData
Dataand
andTask
TaskManagement
ManagementLayer
Layer
CoG
CoGAbstraction
AbstractionLayer
Layer
CoG
CoG
CoG
GT2
CoG
CoG
GT3
OGSI
classic
CoG
CoG
GT4
WS-RF
CoG
CoG
CoG
CoG
Condor Unicore
CoG
CoG
SSH
CoG
CoG
Others
Avaki
SETI
Task
Handler
The class diagram
is the
same for all grid
tasks (running jobs,
modifying files,
moving data).
Task
Task
Specification
Service
Security
Context
Classes also abstract toolkit
provider differences. You set
these as parameters: GT2,
GT4, etc.
Service
Contact
Java COG Summary

The Java COG 4 interfaces provide high level
abstractions for building Grid clients.
• Abstract out differences between Grid toolkits.
• 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
• Desktops, grid shells, and of course portals.
• Portlets are a well known way to build reusable
portal components.
Building Grid Portlets
with Java Server Faces
Limitations of Portlets

Portlets provide a way to bundle and share a
complete application.
• RSS portlet, GridFTP portlet, SRB portlet, etc.
• Portlets combine the user interface view and
action code.

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.”
• Combines “GridFTP” and “Job Submit” portlets…
• Or maybe OGSA-DAI or SRB or ….

We need a way for the view and action code
must be developed from reusable parts.
JSF and Science Gateways

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.

But also, Java Beans can be easily serialized
with XML.
• Castor, XML Beans
• Marshal and un-marshal user input for persistent
storage in XML storage services

OGSA-DAI, GPIR, WS-Context
• Potentially, can develop backing code as XML
Schema and generate the code.
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.
COG Bean Wrappers

Recall the COG structure
• Executable tasks abstract basic grid
actions and hide toolkit version
differences.
• These tasks can be collected into filebased 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.
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.
Task Submission Form
Corresponding JSF snippets
<o:taskGraph id="myGraph" method="#{taskgraph.test}" >
<o:task id="task1" method="task.create" type="FileTransfer" />
<o:task id="task2" method="task.create" type="JobSubmit" />
<o:task id="task3" method="task.create" type="FileTransfer" />
<o:taskAdd name="task1" method="taskgraph.add" />
<o:taskAdd name="task2" depends="task1" method="taskgraph.add" />
<o:taskAdd name="task3" depends="task2" method="taskgraph.add" />
</o:taskGraph>
<h:panelGrid columns="3" >
<h:outputText value="Hostname (*) "/>
<h:inputText value="#{task.hostname}"/>
</h:panelGrid>
<h:panelGrid columns="3" >
<h:outputText value="Provider (*) "/>
<h:inputText value="#{task.provider}"/>
</h:panelGrid>
<h:panelGrid columns="2">
<h:commandButton id="submit" value="Submit" action="#{taskgraph.submitAction}"/>
<h:commandButton value="Clear" type="Reset"/>
</h:panelGrid>
Task Monitoring with JSF
Data Model
Corresponding Java class.
public class Job {
private String jobId;
private String status;
private String submitDate;
private String finishDate;
}
<h:dataTable value="#{jobData.jobs}" var="job">
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Job ID" />
</f:facet>
<h:outputText value="#{job.jobId}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Submit Date"
/>
</f:facet>
<h:outputText value="#{job.submitDate}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Finish Date"
/>
</f:facet>
<h:outputText value="#{job.finishDate}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Status" />
</f:facet>
<h:outputText value="#{job.status}"/>
</h:column>
</h:dataTable>
Extended Slides
The Java CoG Kit
Gregor von Laszewski
Argonne National Laboratory
University of Chicago
[email protected]
http://www.cogkit.org
(as interpreted by MEP)
CoG Kits


CoG Kits make Grid programming simple and
new technologies are easy to integrate
We focus on a CoG Kit for Java
• Python also available (K. Jackson, LBNL)
• Availability: Java CoG Kit since 1997

The CoG provides two important things
• A higher level client programming environment
than stubs.
• A 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
CoG Abstraction Layers
Nano
materials
BioDisaster
Informatics
Management
Applications
Portals
Development
Support
CoGGridfaces
GridfacesLayer
Layer
CoG
CoG
CoG GridIDE
GridIDE
CoGData
Dataand
andTask
TaskManagement
ManagementLayer
Layer
CoG
CoGAbstraction
AbstractionLayer
Layer
CoG
CoG
CoG
GT2
CoG
CoG
GT3
OGSI
classic
CoG
CoG
GT4
WS-RF
CoG
CoG
CoG
CoG
Condor Unicore
CoG
CoG
SSH
CoG
CoG
Others
Avaki
SETI
Task
Handler
The class diagram
is the
same for all grid
tasks (running jobs,
modifying files,
moving data).
Task
Task
Specification
Service
Security
Context
Classes also abstract toolkit
provider differences. You set
these as parameters: GT2,
GT4, etc.
Service
Contact
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);
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);
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);
Coupling CoG Tasks


The COG
abstractions also
simplify creating
coupled tasks.
Tasks can be
assembled into
task graphs with
dependencies.
• “Do Task B after
successful Task A”

Graphs can be
nested.
Java COG Summary

The Java COG 4 interfaces provide high level
abstractions for building Grid clients.
• Abstract out differences between Grid toolkits.
• 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
• Desktops, grid shells, and of course portals.
• Portlets are a well known way to build reusable
portal components.
Building Grid Portlets
with Java Server Faces
Limitations of Portlets

Portlets provide a way to bundle and share a
complete application.
• RSS portlet, GridFTP portlet, SRB portlet, etc.
• Portlets combine the user interface view and
action code.

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.”
• Combines “GridFTP” and “Job Submit” portlets…
• Or maybe OGSA-DAI or SRB or ….

We need a way for the view and action code
must be developed from reusable parts.
PWSCF Web Forms for
Submission
Java Server Faces Overview

JSF can solve the reusable portlet
widget problem.
• JSF can also work in “standalone” mode
outside of portlets.
• Potentially independent of Web
applications.



XUL and Swing widget bindings
We will first examine JSF generally
Conclude with integrating JSF and COG
Advantages of JSF

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 maintain fragile naming
conventions for <input> tags.

Developers only need to develop JavaBeans
and tag libraries.
• Beans are independent of Web applications.
• Can be easily written and tested outside of servlet
containers.
• Compatible popular “Inversion of Control” based
systems like JSF and Spring
JSF and Science Gateways

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.

But also, Java Beans can be easily serialized
with XML.
• Castor, XML Beans
• Marshal and un-marshal user input for persistent
storage in XML storage services

OGSA-DAI, GPIR, WS-Context
• Potentially, can develop backing code as XML
Schema and generate the code.
A JSF Example
<HTML>
<HEAD> <title>Hello</title> </HEAD>
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<body bgcolor="white">
<f:view>
<h:form id="entryForm" >
<h2> Enter some text in the form below</h2>
<h:inputText id="userSt"
value="#{multiEventBean.userString}"/>
<h:commandButton id="submit"
action="success" value="Submit" >
<f:actionListener type="multiEventTest.Listener1"/>
<f:actionListener type="multiEventTest.Listener2"/>
</h:commandButton>
</h:form>
</f:view>
</body>
</HTML>
The JSF Page

Note everything with <f:> or <h:> namespace
prefix is a JSF tag.
• Usually, <h:> tags mimic HTML widgets.
• <f:> is for non-rendered stuff.
• Everything else is good old HTML.

There are three different Java classes here.
• They are all in the package multiEventTest
• multiEventBean.java is just a bean with typical get/set
methods.
• Listener1.java and Listener2.java implement the
javax.faces.event.ActionListener interface.


All 3 classes are called when you click the command
button.
Also, take a look at <inputText>. This is roughly
equivalent to <input name=“” value=“”>.
• But no name needed. JSF handles parameter names for
you and connects them to the beans you specify.
• This greatly simplifies writing generic actions.
A Simple Example: HtmlDataGrid
<%@ taglib uri="http://java.sun.com/jsf/html" prefix="h" %>
<%@ taglib uri="http://java.sun.com/jsf/core" prefix="f" %>
<f:view>
<h2> This shows an example of how to use
HtmlDataTable to display some results.
</h2>
<h:dataTable value="#{ValueBean.itemList}" var="values" border="1">
<h:column>
<f:facet name="header">
<h:outputText value="Column 1"/>
</f:facet>
<h:outputText value="#{values.value1}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText value="Column 2"/>
</f:facet>
<h:outputText value="#{values.value2}"/>
<h:outputText value="#{values.value2}"/>
</h:column>
</h:dataTable>
</f:view>
It Looks Like This
Some Explanation

The <h:dataTable> binds to a particular data set
with value=“ValueBean.itemList”.
• ValueBean.itemList must be java.util.List, java.sql.ResultSet
or similar.
• The values of these lists may be beans also.

The var=“” just defines a useful internal value.
• 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.


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.
JSF Magic: Data Models

The M in MVC is the Data Model
• “Abstract” representation of a data structure


That is, not tied to the display of the data (“view”)
JSF DataModel extension classes include
• Arrays: wrap arrays of Java objects
• Lists: wraps a java.util.List of Java objects
• Results: for JSTL’s Result object, which itself wraps SQL
ResultSets.
• ResultSets: also for JDBC, wraps the ResultsSet object directly.
• Scalar: Wraps an individual Java object.


Typically, these should follow Bean patterns for naming
member data and their associated getter/setters.
You can write your own specialized Data Models.
• XMLDataModel, for wrapping an XML data bean, comes to mind.
• RSSDataModel is another that I found.

These are associated with UIData classes in the JSF page for
display.
• HtmlDataTable is an example.
JSF Form Validators

The user interface stuff (<f:> and
<h:>) has lots of built-in validators
• 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 the string has the right length.

You can extend to write your own
specialized validators
Integrating JSF and COG 4
Mehmet Nacar and Marlon Pierce
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.
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.
JSF Task Management Class
Structure
«interface»
GenericGridBean
TaskListenerBean
1
TaskGraphListenerBean
1
TaskBeanManager
TaskGraphBeanManager
*
*1
1*
TaskBean
TaskGraphBean
1
*
*
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.
Managing Multiple Tasks
HashMap
JSF Form
Task Manager
JSF
retrieve
Task Bean 1
Task Bean 2
Task Bean
register
JSF
Task Bean 3
Managed Beans
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.
Constructing Task Graphs
JSF Request Form
HashMap
TaskGraph Manager
JSF
retrieve
TaskGraph 1
register
TaskGraph 2
TaskGraphBean
JSF Monitoring
Form
TaskGraph 3
JobSubmit Bean
FileTransfer Bean
FileOperation Bean
Managed Beans
Task Submission Form
Corresponding JSF snippets
<o:taskGraph id="myGraph" method="#{taskgraph.test}" >
<o:task id="task1" method="task.create" type="FileTransfer" />
<o:task id="task2" method="task.create" type="JobSubmit" />
<o:task id="task3" method="task.create" type="FileTransfer" />
<o:taskAdd name="task1" method="taskgraph.add" />
<o:taskAdd name="task2" depends="task1" method="taskgraph.add" />
<o:taskAdd name="task3" depends="task2" method="taskgraph.add" />
</o:taskGraph>
<h:panelGrid columns="3" >
<h:outputText value="Hostname (*) "/>
<h:inputText value="#{task.hostname}"/>
</h:panelGrid>
<h:panelGrid columns="3" >
<h:outputText value="Provider (*) "/>
<h:inputText value="#{task.provider}"/>
</h:panelGrid>
<h:panelGrid columns="2">
<h:commandButton id="submit" value="Submit" action="#{taskgraph.submitAction}"/>
<h:commandButton value="Clear" type="Reset"/>
</h:panelGrid>
Task Monitoring with JSF
Data Model
Corresponding Java class.
public class Job {
private String jobId;
private String status;
private String submitDate;
private String finishDate;
}
<h:dataTable value="#{jobData.jobs}" var="job">
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Job ID" />
</f:facet>
<h:outputText value="#{job.jobId}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Submit Date"
/>
</f:facet>
<h:outputText value="#{job.submitDate}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Finish Date"
/>
</f:facet>
<h:outputText value="#{job.finishDate}"/>
</h:column>
<h:column>
<f:facet name="header">
<h:outputText style="font-weight: bold" value="Status" />
</f:facet>
<h:outputText value="#{job.status}"/>
</h:column>
</h:dataTable>
Expressing Task Graphs with Tags
<%@taglib uri="http://java.sun.com/jsf/core" prefix="f"%>
<%@taglib uri="http://java.sun.com/jsf/html" prefix="h"%>
<%@taglib uri="http://www.ogce.org/gsf/task" prefix="o"%>
………
………
<o:taskGraph id="myGraph" method="#{taskgraph.test}" >
<o:task id="task1" method="task.create" type="FileTransfer" />
<o:task id="task2" method="task.create" type="JobSubmit" />
<o:task id="task3" method="task.create" type="FileTransfer" />
<o:taskAdd name="task1" method="taskgraph.add" />
<o:taskAdd name="task2" depends="task1" method="taskgraph.add" />
<o:taskAdd name="task3" depends="task2" method="taskgraph.add" />
</o:taskGraph>