Writing Controls Applications on JavaTM

1
Writing Controls Applications on JavaTM

• An overview of the infrastructure for the user
  application development in Accelerator Controls
  Department.June 30, 2003Andrey Petrov

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Agenda

• Application Framework
• Application Index
• Covered Development of console user
  applications.
• Not covered Development of Open Access Clients,
  servelts, and other server-side programs.

3
I

• Application Framework

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Application Framework Definition

• A library of reusable components for the
  development of console user applications.
• Reference guide is Beams-doc-688, or
  http//www-bd.fnal.gov/controls/java/
  framework/af-guide.pdf

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Application Framework Functions

• Interacts with Application Index services
  (property repository, heartbeat service, central
  logging, operation locks, etc.)
• Provides a uniform application's look-and-feel
  (for swing applications)
• Implements some common functions (printing, image
  capture, DAE connection, message window, etc.).

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Classpath

• framework.jar (gov.jar is not enough), or
• framework-lite.jar (without swing)
• mail.jar
• activation.jar
• jhall.jar
• jlfgr-1_0.har
• govcore.jar
• jconn2.jar

af_bunch.jar
for DAE connection
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Core Application Framework Classes

• ApplicationManager implements most of the
  functions, not related to GUI
• DaeSupport serves the DAE connection
• Implementations of user interfacesJControlsFram
  e, JSimpleControlsFrame, JControlsDialog0, 1, 2.

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Application Manager

• Singleton
• All public methods are static
• Must be initialized at the application startup
• public static void main( String args )
  ApplicationManager.init( args ) / rest of the
  code /

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Frame Dialog Hierarchy
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Graphical User InterfaceJControlsFrame
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JControlsFrame Features

• Dynamic GUI generation from the interface
  descriptors (text files)
• Persistent frame size and location
• Predefined actions
• A "smart" default close operation
• 1st frame EXIT_ON_CLOSE,
• others DISPOSE_ON_CLOSE
• Splash screen for the first frame.

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Interface Descriptor

• An XML file, that describes the appearance of the
  whole frame, menu bar, toolbar, and status bar
• Has the same name, as the corresponding frame
  (with .xml extension), and must be placed in the
  same directory
• Supports inheritance
• Three logical levels.

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Interface DescriptorStructure

• ltframe gt ? 1. root element
• ltmenu id""gt ? 2. element description
• item1 ? 3. sub-element IDs
  item2 item3
• lt/menugt
• lt/framegt

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Inheritance of Interface Descriptors
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Interface Descriptor Example I

• ltframe menuBarID"MenuBar"
  toolBarID"ToolBar" statusBarID"StatusBar"
  restoreSize"true" restoreLocation"true"
  visibleOnStartup"true"gt
• lt!-- code omitted --gt
• lt/framegt

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Interface Descriptor Example II

• lttool_bar id"ToolBar"gt
• Cut Copy Paste
• lt/tool_bargt

• ltitem id"Cut" mnemonic"t"
  actionCommand "CutAction" accelerator
  "CtrlX" icon"" enabled"false"
• /gt

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Interface Descriptor Example III

• MyFrame.xml
• lttool_bar id"ToolBar"gt
• !default Delete
• lt/tool_bargt

• JControlsFrame.xml
• lttool_bar id"ToolBar"gt
• Cut Copy Paste
• lt/tool_bargt

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Polymorphism

• ltitem id"Cut"mnemonic"t"actionCommand
  "CutAction"accelerator "CtrlX"icon""enabl
  ed"false"
• /gt

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Getting GUI Components

• ControlsWidget w getWidget( "Cut" )
• w.setEnabled( true )w.setSelected( false )
  // radio buttonsw.setText( "Any Key" )
• Object objs w.getComponents()

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Handling Events

• Action a new AbstractAction() public void
  actionPerformed( ActionEvent e )
  System.out.println( "!!!" )
• getActionMap().put( "CutAction", a )

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Predefined Actions

• Export To File
• Send Mail
• Post E-log Message
• Print
• Page Setup
• Cut
• Copy
• Copy Special
• Paste

• Select All
• DAE Connection
• Message Viewer
• Application Properties
• Logging
• Help Topics
• About
• Exit

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Custom Frame Initialization

• jbInit method is used for the custom
  initialization of the frame (e.g., placing
  elements on the content pane).
• jbInit should not be called explicitly (this is
  a duty of JControlsFrame)
• The local variables are not initialized when
  jbInit is invoked see documentation

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"Hidden" Functions ofApplication Framework

• Access to the property repository
• Self-determination service (application finds
  itself in the Application Index database)
• Heartbeat service (application notifies
  Application Index, that it is running)
• Operation locks
• Central logging.

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Application Properties

• Named string values, used for program
  configuration and keeping of persistent data
• Properties are stored in local files and on the
  server
• Name and value lt 256 chars both.

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Property Sources

• Global framework configuration file(the user can
  not change it)
• Application property file(optional, created by
  the user)
• Property repository on the server(user may have
  write access).
• Loading order 1 ? 2 ? 3.

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Application Property File

• ltapp_namegt.properties,where app_name name of
  the main class property file must be placed in
  the same directory.
• application.titleTest Application
  application.version0.1.2 application.authorAndr
  ey Petrovdae.connect1

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Property Repository

• http//www-bd.fnal.gov/appix/select/props
• Used to manage properties online and store data
  changed in running applications (e.g., user
  e-mail).
• Properties can be user-specific and
  application-specific.
• Properties, changed in running applications, are
  always user-specific.

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Using Properties In Application

• Properties p ApplicationManager.getPropertie
  s()
• String s p.getProperty( "foo" )
• // "foonew_value" will be stored// on the
  serverp.setProperty( "foo", "new_value" )

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Self-determination Service

• Determines the application's main class and type
  of the launcher (standalone, web-startable,
  etc.)
• Search for the application's description in
  Application Index database
• ApplicationManager.getAppDescriptor()

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Heartbeat Service

• Notifies Application Index, that the application
  is launched or terminated
• Notifies Application Index, that the application
  is running (every 6 minutes) application usage
  history is available online.
• Available only for the registered applications.
• framework.heartbeat0 ? disables

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Operation Lock Service

• Allows to set named locks in order to avoid the
  concurrent execution of critical routines in
  multiple instances of one application.
• Locks are automatically released at the
  application termination
• Available only for the registered applications.

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Operation Lock Example

• try ApplicationManager.
  setOperationLock( "foo" ) catch (Exception ex)
  // The lock is already set
• ApplicationManager. releaseOperationLock(
  "foo" )

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Central Logging

• Instead of System.out.println( )
• Logging records are stored in a database on the
  server side and available online
• Automated purge (once a day), every application
  may have an individual "storage time" for logging
  records (default 1 day).
• Available only for the registered applications.

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Logging API

• Logger log Logger.getLogger( "" )
• log.warning( "This is a warning" )
• try // some code catch (Exception ex)
  log.log( Level.SEVERE, "Error", ex )

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Logging Configuration

• Custom handlers MessageViewerHandler,
  AppixHandler
• Configuration through application properties
  (default values in property files)
• Configuration at the runtime through GUI (stored
  in the property repository).

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Logging Configuration Dialog
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DAE Connection

• DAE connection getting of DaqUser object
• For the console applications, DaqUser must be
  obtained from Application Manager.
• Then DaqUser is used to create DAQ jobs.

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DAE Connection Requirements

• Client machine must be inside the firewall
• Two libraries are required in the classpath
  govcore.jar and jconn2.jar.
• User, node, and application must have enough
  privileges to do settings.

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DAE Connection GUI
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Getting DaqUser

• ApplicationManager.getDaqUser()
• Returns either DaqUser instance, or null
• Application (service) permissions are
  automatically set in DaqUser
• Do not cache DaqUser in the program!

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DaeConnectionListener

• public void daeStatusChange( short oldStatus,
  short newStatus )
• public void settingsLockChange( boolean newVal
  )
• public void daeException( Exception exception
  )
• ApplicationManager.getDaeSupport().
  addDaeConnectionListener( )

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Settings

• By default, settings are locked, except of the
  Main Control Room users
• Maximum unlock time is considered
• Settings may be unlocked from GUI.
• Do not unlock settings programmatically in
  productional versions!

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DAE Connection Configuration
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DAE Security

• DAE uses a user/node pair for authorization
• If this pair is not found in DB, the Kerberos
  authentication is requested
• All users with valid user/node combination are
  allowed to do readings
• Users, nodes, and applications have settings
  privileges and maximum unlock time

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DAE Security Example
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Security Service

• Will be ready soon
• Single Sign-On based on MIT Kerberos
• In most cases will use existing cached Kerberos
  ticket (JAAS extension)
• This ticket will be forwarded to the server
  (servlets?), in order to present the client-side
  user (GSS-API).

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II

• Application Index
• (APPiX)

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Application Index Funtions

• Keeps all information on applications in the
  database
• Provides GUI for editing and monitoring of
  application data
• Provides data for the running applications
  through web-services.

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APPiX Architecture
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Representation Of An Application In Database
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Application Index GUI

• Main page http//www-bd.fnal.gov/appix
• An applet-based application launcher
• Standalone application launcher
• Read-only access for all (except of a small
  restricted area)
• Authentication required to modify data
• From outside Fermilab read-only access ever.

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(No Transcript)
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Launching An Application

• Web launcher (based on an applet), and Standalone
  application browser (web-startable itself)
• 7 program types, each has own launching
  procedure
• Web launcher does not support STDALONE type

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Program Types
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JWS-AUTO Programs

• A dynamic generation of JNLP file, basing on the
  application record in the database.
• User does not have to write and maintain JNLP
  file.
• JNLP generator is being kept up-to-date (to
  resolve certain JRE bugs, etc.).

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Application Tree

• Top level machine name (B, C, F, )
• There may be several references to one
  application
• Each reference may have individual command line
  arguments (STDALONE, JWS-AUTO).

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Information Needed To Register An Application

• Application Name
• Application description lt 256 chars
• Help URL, if any
• Responsible person
• Program type
• Main class (STDALONE, JWS-AUTO), or URL
• Required libraries (jars)
• Desired place in the application tree

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Q A

• Project URLhttp//www-bd.fnal.gov/appix
• All questionsapetrov_at_fnal.gov