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Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 1 Java and JCA / CAJ Kenneth Evans, Jr. October 12, 2004 Part of the.

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Presentation on theme: "Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 1 Java and JCA / CAJ Kenneth Evans, Jr. October 12, 2004 Part of the."— Presentation transcript:

1 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 1 Java and JCA / CAJ Kenneth Evans, Jr. October 12, 2004 Part of the EPICS “Getting Started” Lecture Series Slightly Modified for EPICS2006 at VECC By Kazuro Furukawa July 13, 2006

2 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 2 Outline  Java  Java and EPICS  Overview of JCA  Examples  SimpleJCAGet  SimpleJCAMonitor  JProbe

3 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 3 Java  Java is designed to be platform independent  Write once, run everywhere  Java programs are interpreted by another program, possibly on another machine  The Java Virtual Machine (Java VM)  Java technology includes  J2SEStandard Edition  J2EEEnterprise Edition (Multi-tier business apps)  J2MEMicro Edition (Phones, PDAs, etc.)  Java is advertised to be all of these SimpleArchitecture neutralObject oriented PortableDistributedHigh performance InterpretedMultithreadedRobust DynamicSecure

4 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 4 Java and EPICS  EPICS Channel Access is native code  Not platform independent  Build cycle is edit – compile [to machine code] - link - run  Pure Java  Build cycle is edit – compile [to byte code] – run [anywhere]  Java Native Interface [JNI] is used to access native code  Not “Pure Java”  No longer platform independent  You generate shared object or DLL libraries that must be used with the Java program  You can write your own JNI  Not that hard if you know Channel Access  The EPICS build system handles Java projects and JNI  Ant is an alternative

5 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 5 JCA  Stands for Java Channel Access  JCA is a JNI implementation of an EPICS Channel Access client library for Java  Provides equivalents to most of the Channel Access API  Developed by Eric Boucher while at the APS  Currently taken over by Cosylab  Available for download at  http://jca.cosylab.com/  Latest version is 2.1.7 at Cosylab  JCA Version 1 uses EPICS Base 3.13  JCA Version 2 uses EPICS Base 3.14  Channel Access is threaded  Allows for preemptive callbacks  Works better with Java, which is inherently threaded

6 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 6 CAJ  CAJ is a Java replacement for Channel Access  Developed at Cosylab (Control Systems Laboratory)  Located in Ljubljana in Slovenia  Cosylab also develops VDCT  Available for download at  http://caj.cosylab.com/  Latest version is 1.0.5  Allows your programs to be “Pure Java”  Is used with JCA  Replaces JNI implementation  Requires replacing only one line of code  jca.createContext(JCALibrary.JNI_THREAD_SAFE);  jca.createContext(“com.cosylab.epics.caj.CAJContext”);

7 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 7 Requirements  Java J2SE installed (Current [suggested] version is 1.4.2)  JCA  Java libraries  Download source and/or JAR files from the web  Native JNI libraries  Download from the web or build them  Currently found with the 2.1.7 distribution  jca.dllWindows  libjca.soUnix (Currently Linux, Solaris, Darwin?)  Your project  JCA files need to be in your CLASSPATH  UNIX: Shared object library needs to be in your LD_LIBRARY_PATH  Windows: DLL needs to be in your PATH

8 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 8 Resources  EPICS web pages  http://www.aps.anl.gov/epics/index.php  Look under Extensions, then JCA  JCA 2.1.7 API  http://jca.cosylab.com/apidocs/index.html  JCA 2.1.2 API  http://www.aps.anl.gov/xfd/SoftDist/swBCDA/jca/2.1.2/api/index.htmlI  CAJ 1.0.5  http://caj.cosylab.com/manual.html  Java Tutorial  http://java.sun.com/learning/tutorial/index.html  J2SE Documentation  http://java.sun.com/reference/api/index.html  J2SE 1.4.2 API (Javadoc)  http://java.sun.com/j2se/1.4.2/docs/api/overview-summary.html

9 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 9 JCA Packages  Five Packages  gov.aps.jcaChannel-Access-like routines  gov.aps.jca.configurationConfiguration  gov.aps.jca.dbrDBR types  gov.aps.jca.eventEvent handling  gov.aps.jca.jniNative interface functions

10 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 10 gov.aps.jca  This is the package you will use most directly  Classes  CASeverityEnum  CAStatusJCALibrary  ChannelMonitor  Channel.ConnectionStateValuedEnum  Context  Exceptions  CAExceptionTimeoutException

11 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 11 JCALibrary  Initializes JCA JCALibrary jca=JCALibrary.getInstance();  There is only one instance  Used to create contexts and manage JCA configuration info  Properties  JNI_THREAD_SAFEpreemptive  Suggested for Java, which is inherently threaded  JNI_SINGLE_THREADEDnon-preemptive  Methods  createContext  getProperty  listProperties  getVersion, getRevision, getModification

12 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 12 Context  Corresponds to a Channel Access context  Created by JCALibrary.createContext createContext(JCALibrary.JNI_SINGLE_THREADED) createContext(JCALibrary.JNI_THREAD_SAFE)  Controls all IO  You can have more than one context  Methods  createChannel  flushIO, pendIO, pendEvent, poll  attachCurrentThread  addContextExceptionListener, removeContextExceptionListener  addContextMessageListener, removeContextMessageListener  destroy

13 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 13 Channel  Represents a Channel Access channel  Created by Context.createChannel createChannel(String name, connectionListener l)  Properties  CLOSEDCONNECTED  DISCONNECTEDNEVER_CONNECTED  Methods  get, many overloads  put, many overloads  getName, getConnectionState, getElementCount, etc.  addMonitor  addConnectionListener, removeConnectionListener  addAccessRightsListener, removeAccessRightsListener  destroy

14 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 14 Monitor  Represents a Channel Access monitor  Created by Channel.addMonitor addMonitor(DBRType type, int count, int mask, MonitorListener l)  Properties  ALARMLOGVALUE  Methods  addMonitorListener, removeMonitorListener  getMonitorListener, getMonitorListeners  clear  getChannel, getContext  getCount, getMask, getType  isMonitoringAlarm, isMonitoringLog, isMonitoringValue

15 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 15 MonitorListener  Part of gov.aps.jca.event  One method  monitorChanged  Example private class MyMonitorListener implements MonitorListener { public void monitorChanged(MonitorEvent ev) { // Call my handler onValueChanged(ev); } };  The value and status comes with the MonitorEvent

16 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 16 MonitorEvent  Part of gov.aps.jca.event  Methods  getDBRHow you get the value  getStatusHow you determine the status  Example if(ev.getStatus() == CAStatus.NORMAL) { DBR dbr=ev.getDBR(); double [] value=((DOUBLE)dbr).getDoubleValue(); }

17 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 17 Event Types  MonitorListenerMonitorEvent  GetListenerGetEvent  PutListenerPutEvent  AccessRightsListenerAccessRightsEvent  ConnectionListenerConnection Event  ContextExceptionListenerContextExceptionEvent  ContextMessageListenerContextMessageEvent  Events all inherit from CAEvent  They all work similarly to Monitor  Call the routine that fires the event when it occurs  Add a listener with the appropriate handler  Get the data from the event that is passed to your handler

18 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 18 gov.aps.jca.dbr  Implements the EPICS DBR_xxx types  Interfaces  DOUBLE, FLOAT, INT, STRING, TIME, CTRL, etc.  Primary Class  DBR  Subclasses of DBR  DBR_Double, DBR_Float, DBR_Int, DBR_STS_Double, etc.  Example: DBR_STS_Double  Interfaces  STS, DOUBLE  Extends  DBR_Double  Subclasses  DBR_GR_Double, DBR_Time_Double

19 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 19 SimpleJCAGet package simplejca; import gov.aps.jca.*; import gov.aps.jca.dbr.*;

20 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 20 SimpleJCAGet public class SimpleJCAGet { public static void main(String[] args) { SimpleJCAGet simpleJCAGet = new SimpleJCAGet(); JCALibrary jca=null; Context ctxt=null; Channel chan=null; // Parse the command line if(!simpleJCAGet.parseCommand(args)) System.exit(1); if(!simpleJCAGet.pvSpecified) { System.err.println("No PV specified\n"); System.exit(1); }

21 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 21 SimpleJCAGet // Initialize and search try { // Get the JCALibrary instance jca=JCALibrary.getInstance(); // Create a non-preemptive context context=jca.createContext( JCALibrary.JNI_SINGLE_THREADED); // Search chan=ctxt.createChannel(simpleJCAGet.name); // Wait for search ctxt.pendIO(simpleJCAGet.timeout); } catch(Exception ex) { System.err.println("Search failed for " + simpleJCAGet.name + ":\n" + ex); System.exit(1); }

22 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 22 SimpleJCAGet // Get the first value as a String try { // Get the value String [] value; value=((STRING)chan.get(DBRType.STRING,1)). getStringValue(); // Wait for the get ctxt.pendIO(simpleJCAGet.timeout); // Print the value System.out.println("The value of " + simpleJCAGet.name + " is " + value[0]); } catch(Exception ex) { System.err.println("Get failed for " + simpleJCAGet.name + ":\n" + ex); System.exit(1); }

23 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 23 SimpleJCAGet // Clean up try { // Clear the channel chan.destroy(); // Destroy the context ctxt.destroy(); } catch(Exception ex) { System.err.println("Clean up failed for " + simpleJCAGet.name + ":\n" + ex); System.exit(1); } // Successful exit System.exit(0); }

24 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 24 SimpleJCAGet output java.exe -classpath \SimpleJCA.jar; \jca-2.1.7.jar simplejca.SimpleJCAGet evans:calc The value of evans:calc is 3

25 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 25 SimpleJCAMonitor  Similar to SimpleJCAGet  Imports, parsing the command line, etc. are the same  We will have listeners  We will use JNI_THREAD_SAFE ( preemptive)  We will use flushIO and not pendIO, etc.

26 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 26 SimpleJCAMonitor /** Implementation of Connection Listener class */ private class SJCAConnectionListener implements ConnectionListener { public void connectionChanged(ConnectionEvent ev) { onConnectionChanged(ev); } }; /** Implementation of MonitorListener class */ private class SJCAMonitorListener implements MonitorListener { public void monitorChanged(MonitorEvent ev) { onValueChanged(ev); } };

27 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 27 SimpleJCAMonitor // Instance of SimpleJCAMonitor SimpleJCAMonitor sjcam=new SimpleJCAMonitor(); // Initialize JCA try { // Get the JCALibrary instance jca=JCALibrary.getInstance(); // Create a preemptive context, default configuration ctxt=jca.createContext(JCALibrary.JNI_THREAD_SAFE); } catch(Exception ex) { System.err.println("Initialization failed for " + sjcam.name + ":\n" + ex); System.exit(1); }

28 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 28 SimpleJCAMonitor // Search try { // Search chan=ctxt.createChannel(sjcam.name, sjcam.new SJCAConnectionListener()); ctxt.flushIO(); } catch(Exception ex) { System.err.println("Search failed for " + sjcam.name + ":\n" + ex); System.exit(1); }

29 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 29 SimpleJCAMonitor private void onConnectionChanged(ConnectionEvent ev) { Channel ch=(Channel)ev.getSource(); Context ctxt=ch.getContext(); // Start a monitor on the first connection if(connectionCounter == 0 && ch.getConnectionState() == Channel.CONNECTED) { try { // Add a monitor listener and flush ch.addMonitor(DBRType.STRING,1, Monitor.VALUE|Monitor.LOG|Monitor.ALARM, new SJCAMonitorListener()); ctxt.flushIO(); } catch(Exception ex) { ex.printStackTrace(); }

30 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 30 SimpleJCAMonitor // Print connection state if(ch.getConnectionState() == Channel.CONNECTED) { System.out.println(ch.getName() + " is connected"); } else if(ch.getConnectionState() == Channel.CLOSED) { System.out.println(ch.getName() + " is closed"); } else if(ch.getConnectionState() == Channel.DISCONNECTED) { System.out.println(ch.getName() + " is disconnected"); } else if(ch.getConnectionState() == Channel.NEVER_CONNECTED) { System.out.println(ch.getName() + " is never connected"); }

31 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 31 SimpleJCAMonitor private void onValueChanged(MonitorEvent ev) { Channel ch=(Channel)ev.getSource(); Context ctxt=ch.getContext(); // Check the status if (ev.getStatus() != CAStatus.NORMAL) { System.err.println("monitorChanged: Bad status ” ); } // Get the value from the DBR try { DBR dbr=ev.getDBR(); String [] value=((STRING)dbr).getStringValue(); System.out.print(SJCAUtils.timeStamp() + " " + getName() + ": “ + value[0]); } catch(Exception ex) {... }

32 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 32 Simple JCAMonitor output Oct 11, 2004 10:36:43.661 Starting Simple JCA Monitor Oct 11, 2004 10:36:44.083 Search successful for: evans:calc CHANNEL : evans:calc TYPE : gov.aps.jca.dbr.DBRType[DBR_DOUBLE=6] COUNT : 1 STATE : gov.aps.jca.Channel$ConnectionState[CONNECTED=2] HOSTNAME : ctlapps4l188.aps4.anl.gov:5064 READ : true WRITE : true Oct 11, 2004 10:36:44.208 evans:calc is connected Oct 11, 2004 10:36:44.224 evans:calc: 2 Oct 11, 2004 10:36:44.224 evans:calc: 3... Oct 11, 2004 10:36:53.240 evans:calc: 3 Oct 11, 2004 10:36:53.740 evans:calc: 4 Oct 11, 2004 10:36:54.036 All Done

33 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 33 JProbe  JProbe is a simple example that demonstrates using JCA in a Swing GUI

34 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 34 Write once, run everywhere?

35 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 35 Source files for Simple JCA routines  All the source and JAR files should be available with the presentation  LICENSE  SimpleJCA.jar  simplejca  SimpleJCAMonitor.java  SimpleJCAGet.java  SJCAUtils.java  JProbe.jar  jprobe  JProbe.java  MainFrame.java  AboutBoxPanel.java  Stored as SimpleJCA.zip

36 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 36 Some Pointers to Documents  Example files  http://www.aps.anl.gov/epics/  Documents - Training - Developing Client Tools - Java and JCA - Example Files  Build examples of EPICS-Base, etc on several Platforms  http://www-linac.kek.jp/jk/win32/  http://www-linac.kek.jp/jk/linux/  http://www-linac.kek.jp/jk/darwin/

37 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 37 Acknowledgements  JCA was developed by Eric Boucher while at the APS  Matej Sekoranja [Cosylab] has taken over JCA and is developing CAJ  Both of these people were very helpful in getting JCA working for me

38 Kazuro Furukawa, KEK, Jul.2006. Jacva and JCA / CAJ EPICS Workshop 2006, VECC, India 38 Thank You This has been an APS Controls Presentation By Kenneth Evans, Jr. Modified for EPICS2006 at VECC By Kazuro Furukawa

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