Re: [dev] How to create a uno singleton component ?

[Oliver Brinzing]

Hi,

today i started to create my first uno singleton ;-)

idlc, regmerge & javamaker seem to work, regview shows me for example:

 / LogService
                      Value: Type = RG_VALUETYPE_BINARY
                             Size = 110
                             Data = version: 1
                                    documentation: ""
                                    file name: ""
                                    type class: singleton
                                    type name: "logging/LogService"
                                    super type count: 1
                                    super type name 0: "logging/XLogAccess"
                                    field count: 0
                                    method count: 0
                                    reference count: 0

the extension is deployable an i can get an instance, for example:

        oContext = 
createUnoService("com.sun.star.configuration.bootstrap.BootstrapContext")
        oA = oContext.getValueByName("/singletons/logging.LogService")
        oB = oContext.getValueByName("/singletons/logging.LogService")

        msgbox EqualUnoObjects(oA, oB)
       -> return's TRUE

Now i see two problems:

1.     oA = CreateUnoService("logging.LogService")
        oB = CreateUnoService("logging.LogService")
        msgbox EqualUnoObjects(oA, oB)
        -> return's FALSE - do i have 2 instances here ???

 2.   How can i use the static get(xComponentContext) to obtain the instance, 
described here:

http://wiki.services.openoffice.org/wiki/Documentation/DevGuide/ProUNO/C%2B%2B/Mapping_of_Singletons

       changing "LogServiceImpl.java" to a java singleton

        private static LogServiceImpl instance = null;
        private LogServiceImpl(final XComponentContext xComponentContext) {
        }
        public static XLogAccess get(final XComponentContext xComponentContext) 
{
                if (LogServiceImpl.instance == null)
                        LogServiceImpl.instance = new 
LogServiceImpl(xComponentContext);
                return LogServiceImpl.instance;
        }

       will cause an error message: "Can not activate the factory for 
logging.LogServiceImpl beacause
       FactoryHelper can not find a useable constructor "

any hints ?

Oliver

code snippet's:

LogService.idl
                [...]   module logging {
                                interface XLogAccess;
                                singleton LogService : XLogAccess;
                        };

XLogAccess.idl
               [...]  module logging {
                        interface XLogAccess : com::sun::star::uno:: XInterface 
{
                                string getLoggerName();
                                long getLevel();
                               [...]
                      };
               };

LogServiceImpl.java

public class LogServiceImpl extends ComponentBase implements XServiceInfo, 
XLogAccess {

        static final String _serviceName = "logging.LogService";

        public LogServiceImpl(final XComponentContext xComponentContext) {
        }

        public String getImplementationName() {
                return getClass().getName();
        }

        public boolean supportsService(final String name) {
                if (name.equals(LogServiceImpl._serviceName))
                        return true;
                return false;
        }

        public String[] getSupportedServiceNames() {
                return new String[] { LogServiceImpl._serviceName };
        }

        // XLogAccess
        public String getLoggerName() {
                return Log.getName();
        }

        public int getLevel() {
                return Log.getLevel();
        }
}

ServiceProvider.java

public class ServiceProvider {

        public static XSingleServiceFactory __getServiceFactory(
                        final String sImplName, final XMultiServiceFactory 
xMultiFactory,
                        final XRegistryKey xRegistryKey) {

                XSingleServiceFactory xSingleServiceFactory = null;

                if (sImplName.equals(LogServiceImpl.class.getName()))
                        xSingleServiceFactory = FactoryHelper.getServiceFactory(
                                        LogServiceImpl.class, 
LogServiceImpl._serviceName,
                                        xMultiFactory, xRegistryKey);
                return xSingleServiceFactory;
        }

        public static boolean __writeRegistryServiceInfo(
                        final XRegistryKey xRegistryKey) {

                try {
                        XRegistryKey newKey = 
xRegistryKey.createKey(LogServiceImpl.class
                                        .getName()
                                        + "/UNO/SINGLETONS/" + 
LogServiceImpl._serviceName);
                        newKey.setStringValue(LogServiceImpl._serviceName);
                } catch (InvalidRegistryException e) {
                        return false;
                }

                return FactoryHelper.writeRegistryServiceInfo(
                                LogServiceImpl.class.getName(), 
LogServiceImpl._serviceName,
                                xRegistryKey);
        }
}

-- 

GnuPG key 0xCFD04A45: 8822 057F 4956 46D3 352C 1A06 4E2C AB40 CFD0 4A45

signature.asc
Description: OpenPGP digital signature