Re: CAJ can't handle DBR_String

[Hugo Slepicka <hhslepicka@gmail.com>]

Hi Carsten,

This worked for me:

public class CAJBugTest {

    public static void main(String[] args) throws Exception {

        JCALibrary jca = JCALibrary.getInstance();

        Context ctxt = jca.createContext(JCALibrary.CHANNEL_ACCESS_JAVA);

        Channel ch = ctxt.createChannel("LNLS:ANEL:comentario");

        ch.addMonitor(DBRType.STRING, 1, Monitor.VALUE, new MonitorListener() {

            @Override

            public void monitorChanged(MonitorEvent ev) {

            String[] ret = (String[])ev.getDBR().getValue();

            System.out.println(ret[0]);

            }

        });

        ctxt.flushIO();

        Thread.sleep(5000);

        ch.destroy();

        ctxt.destroy();

    }

}

Here is the PV Info:

hslepicka@SOL7-LINUX ~/CT $ cainfo LNLS:ANEL:comentario

LNLS:ANEL:comentario

    State:            connected

    Host:             10.2.105.151:5064

    Access:           read, no write

    Native data type: DBF_STRING

    Request type:     DBR_STRING

    Element count:    1

-- 
Hugo Henrique Slepicka
Engenheiro de Computação
SOL - Software de Operação das Linhas de Luz
LNLS - Laboratório Nacional de Luz Síncrotron
CNPEM - Centro Nacional de Pesquisa em Energia e Materiais
5913 - hugo.slepicka@lnls.br
www.lnls.br

On Wed, Aug 21, 2013 at 10:53 AM, Winkler, Carsten <carsten.winkler@helmholtz-berlin.de> wrote:

Hi,

my initial version used the  connection listener to add monitor with native data type. But it didn't work.

Carsten

"Kasemir, Kay" <kasemirk@ornl.gov> schrieb:

Looks like you are asking for a DBRType.DOUBLE in the addMonitor, but the actual value (string) cannot be converted.
Ask for the 'native' value by adding a connection listener, then inside the connection listener do the addMonitor with the native data type.

-Kay

On Aug 21, 2013, at 5:44 AM, Carsten Winkler <carsten.winkler@helmholtz-berlin.de> wrote:

> Hi all,
>
> it seems CAJ can't handle DBR_String.
> If you request the value of a stringout or stringin EPICS variable you
> always get a NullPointerException.
> Also if you ask for the DESC field of any PV you'll get same error.
> If you dig deeper you see the DBRType of the created channel is
> UNKNOWN.  Where comes this type come from? You find the problem in
> "com.cosylab.epics.caj.CAJChannel.connectionCompleted(int sid, short
> typeCode, int elementCount) ". This function gets the parameter
> "typeCode" and the value of this parameter is "UNKNOWN" instead of
> "STRING". But who sets the "typeCode"? The "typeCode" will be extracted
> from the CA response header (AbstractCAResponseHandler) and here ends my
> trace.
> Did I miss something? Please check my source code and tell me what to do
> to get strings.
>
> public class CAJBugTest {
>     public static void main(String[] args) throws Exception {
>         JCALibrary jca = JCALibrary.getInstance();
>         Context ctxt = jca.createContext(JCALibrary.CHANNEL_ACCESS_JAVA);
>         Channel ch = ctxt.createChannel("INFOCL:scale.DESC");
>         ch.addMonitor(DBRType.DOUBLE, 1, Monitor.VALUE, new
> MonitorListener() {
>             @Override
>             public void monitorChanged(MonitorEvent ev) {
>                 System.out.println(ev.getDBR().getValue());
>             }
>         });
>         ctxt.flushIO();
>         Thread.sleep(5000);
>         ch.destroy();
>         ctxt.destroy();
>     }
> }
>
> Cheers,
> Carsten
>
> ________________________________
>
> Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
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>
> Sitz Berlin, AG Charlottenburg, 89 HRB 5583
>
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>
> http://www.helmholtz-berlin.de
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---

Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

Mitglied der Hermann von Helmholtz-Gemeinschaft Deutscher Forschungszentren e.V.

Aufsichtsrat: Vorsitzender Prof. Dr. Dr. h.c. mult. Joachim Treusch, stv. Vorsitzende Dr. Beatrix Vierkorn-Rudolph
Geschäftsführung: Prof. Dr. Anke Rita Kaysser-Pyzalla, Thomas Frederking

Sitz Berlin, AG Charlottenburg, 89 HRB 5583

Postadresse:
Hahn-Meitner-Platz 1
D-14109 Berlin

http://www.helmholtz-berlin.de