Re: CAJ usage

["J. Lewis Muir" <jlmuir@anl.gov>]

David Dudley wrote:
> Well, getting closer.
>
> I had jca-2.3.1 source downloaded earlier.
>
> Moved to directory and did 'ant', it said:
>
> build.core.java:
>      [echo] Building core classes
>     [javac] Compiling 67 source files to
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/O.core
>     [javac]
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/src/core/gov/aps/jca/dbr/DBR_Double.java:89:
> cannot resolve symbol
>     [javac] symbol  : method format
> (java.util.Locale,java.lang.String,java.lang.Object[])
>     [javac] location: class java.lang.String
>     [javac]                             toValue[i] =
> String.format(Locale.US, formatFString, params);
>     [javac]                                                           
> ^
>     [javac]
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/src/core/gov/aps/jca/dbr/DBR_Double.java:93:
> cannot resolve symbol
>     [javac] symbol  : method format
> (java.util.Locale,java.lang.String,java.lang.Object[])
>     [javac] location: class java.lang.String
>     [javac]                                     toValue[i] =
> String.format(Locale.US, formatEString, params);
>     [javac]                                                            
>        ^
>     [javac]
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/src/core/gov/aps/jca/dbr/DBR_Float.java:91:
> cannot resolve symbol
>     [javac] symbol  : method format
> (java.util.Locale,java.lang.String,java.lang.Object[])
>     [javac] location: class java.lang.String
>     [javac]                             toValue[i] =
> String.format(Locale.US, formatFString, params);
>     [javac]                                                           
> ^
>     [javac]
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/src/core/gov/aps/jca/dbr/DBR_Float.java:95:
> cannot resolve symbol
>     [javac] symbol  : method format
> (java.util.Locale,java.lang.String,java.lang.Object[])
>     [javac] location: class java.lang.String
>     [javac]                                     toValue[i] =
> String.format(Locale.US, formatEString, params);
>     [javac]                                                            
>        ^
>     [javac]
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/src/core/gov/aps/jca/jni/JNIContext.java:147:
> cannot resolve symbol
>     [javac] symbol  : constructor IllegalStateException
> (java.lang.String,java.lang.Throwable)
>     [javac] location: class java.lang.IllegalStateException
>     [javac]       throw new IllegalStateException( "Context not
> initialized", th );
>     [javac]             ^
>     [javac] 5 errors
>
> BUILD FAILED
> /usr/local/EPICS/modules/soft/jca/jca-2.3.1/build.xml:144: Compile
> failed; see the compiler error output for details.
>
> Total time: 5 seconds
>
> Getting closer, I would say.
>
> So, you're saying that caj only replaces the JNI part of jca with a
> java package, instead of the native interface package?

That's correct. Instead of using the EPICS libraries for Channel Access 
communication, CAJ implements the Channel Access protocol in Java.

About your build problem. What archive of JCA did you download? When I 
downloaded the tar-gz file from http://jca.cosylab.com/ and extracted 
it, tar said "tar: A lone zero block at 1809". I downloaded the zip file 
and it extracted cleanly:

$ curl -O http://jca.cosylab.com/distributions/jca-2.3.1-src.zip

Before building JCA, I set EPICS_BASE_RELEASE (sh shell):

$ export EPICS_BASE_RELEASE=/opt/epics-3.14.8.2/base

If you're planning to use the ant install target, you should set 
EPICS_EXTENSIONS to an appropriate value also.

Then I was able to do

$ ant clean
$ ant

If you are planning to use only the CAJ Channel Access implementation, 
you could consider compiling JCA without the native EPICS libraries. 
However, I don't know that this is officially supported. I was able to 
successfully compile JCA without native EPICS libraries by removing the 
build.core.jni target from the depends attribute of the build.core 
target in build.xml:

---replace this---
<target name="build.core" depends="build.core.java,build.core.jni">
---with this (i.e. remove "build.core.jni" target dependency)---
<target name="build.core" depends="build.core.java">
---

In this case, I just did (sh shell)

$ export EPICS_BASE_RELEASE=''
$ ant clean
$ ant

The JAR file is created at "O.core/jca.jar".

-lewis

> > > > Kay-Uwe Kasemir <kasemirk@ornl.gov> 5/8/2007 2:24 PM >>>
> Hi:
>
> You need jca, which gives you
> a) The basic java API, a lot of interfaces, in a jca.jar file.
>     That's what ant complains about with the missing gov.aps.jca.
> b) A JNI implementation of those interfaces,
>     using the CA client lib from EPICS base,
>     in some *so or *dll file.
>
> Just jca works fine, but the problem is that it depends on the
> JNI implementation, i.e. binary, system-dependent code.
> You need to build the JNI part of jca for Win32, Linux, Linux 64-bit,
> OSX-on-ppc, OSX-on-intel, for every version of EPICS base that
> you want to use.
>
> CAJ provides a pure java implementation, so it replaces (b).
> At the SNS, we had some problems with CAJ possibly causing
> hangups of CA server threads on IOCs, but the current hope is
> that that's been fixed as long as you use the latest jca/caj
> and IOCs run R3.14.9.
>
> -Kay
>
>
> On May 8, 2007, at 15:04 , David Dudley wrote:
>
> > I'm trying to configure and use the CAJ library, since I can't be
> sure
> > what kind of machine the application will be used on.  It can  
> > almost be
> > guaranteed that whatever machine it is, it won't have EPICS on it,
> for
> > sure.
> >
> > I downloaded caj-1.1.3-src and caj-1.1.3.tar, and am attempting to
> > figure out how to use it.
> >
> > From the caj-1.1.3 source directory, I can't get ant to operate  
> > without
> > giving pages and pages of errors.  It looks for package
> 'gov.aps.jca',
> > but shows that package does not exist.
> >
> > Still working on getting use to java, I've been a 'c' programmer for
> > around 20 years or so.
> > All I did was go go to the source directory and type 'ant'.  Was
> there
> > something else I was supposed to do as well?
> >
> > David
> >
> > > > > "Matej Sekoranja" <matej.sekoranja@gmail.com> 11/26/2006 1:49 PM
> > Hi,
> >
> > sorry for the late reply.
> >
> > > Is there any additional information on utilizing the Jca library
> > other
> > > than the Tutorial listed?  I'd like to use a 'monitor' function to
> > display
> > > changing data, but there isn't exactly any documentation on it.
> >
> > There is a series of  EPICS training material.
> > Java and JCA can be found here:
> > http://www.aps.anl.gov/aod/bcda/epicsgettingstarted/developtools/ 
> > java.html
> >
> > See also CA client library tutorials.
> >
> > Any help would be appreciated.
> >
> >
> > The best thing is to look at BasicExample source (found in the
> > sources). I
> > attach it anyway.
> >
> > Matej
> > <David Dudley.vcf>