Hi Juerg,
I'm still not clear if you are trying to reference the DataSource service
from within another OSGi service or from some POJO class. The description
of the original problem suggests it is not within an OSGi service as a
failure to inject the non-optional @Reference should have caused that OSGi
service to fail to activate.
If this is indeed a POJO class, you may try something like this:
import java.util.Collection;
import javax.sql.DataSource;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
public class DSExamplePojo {
private Logger logger = LoggerFactory.getLogger(getClass());
public void doSomething() {
// get the bundle this class lives in
Bundle bundle = FrameworkUtil.getBundle(getClass());
// and the bundle context to lookup a service
BundleContext bundleContext = bundle.getBundleContext();
// lookup the service
DataSource ds = null;
Collection<ServiceReference<DataSource>> serviceReferences = null;
try {
serviceReferences =
bundleContext.getServiceReferences(DataSource.class, "(datasource.name
=dbdb)");
} catch (InvalidSyntaxException e) {
logger.error("Failed to get service references", e);
}
if (serviceReferences != null && !serviceReferences.isEmpty()) {
// get the first match
ServiceReference<DataSource> ref =
serviceReferences.iterator().next();
try {
// get the service from the service reference
ds = bundleContext.getService(ref);
} finally {
// cleanup
bundleContext.ungetService(ref);
}
//TODO: use the ds variable to do something here
logger.info("Found DataSource: {}", ds);
}
}
}
Regards,
-Eric
On Mon, Mar 1, 2021 at 1:09 AM JCR <j...@proxymit.net> wrote:
> Yes, the pool is called by a class in an OSGI bundle with the dependency
> shown in my previous email.
>
> But indeed, we have strong reasons that we are talking about a
> classloader issue here. In the meanwhile, I tested the JDBC "vanilla
> approach":
>
> Class.forName("org.mariadb.jdbc.Driver");
> Connection con =
> DriverManager.getConnection("jdbc:mariadb://localhost:3306/dbdb",
> "dbuser1", "pwd");
>
> and a direct DataSource approach:
>
> MariaDbDataSource ds = new MariaDbDataSource();
> ds.setUser("dbuser1");
> ds.setPassword("pwd");
> ds.setServerName("localhost");
> ds.setPortNumber(3306);
> ds.setDatabaseName("dbdb");
> con = ds.getConnection();
>
> The first version returns with a runtime error that the Driver-class is
> not found. The second version behaves similarly
>
> java.lang.NoClassDefFoundError: javax/sql/DataSource
>
> Now, javax.sql is even a standard part of Felix. If I add this
> dependency to pom:
>
> <dependency>
> <groupId>javax.sql</groupId>
> <artifactId>jdbc-stdext</artifactId>
> <version>2.0</version>
> </dependency>
>
> ... Eclipse marks an error saying "Missing artifact
> javax.sql:jdbc-stdext:jar:1.0". That's strange because the jar is in
> /home/juerg/.m2/repository/javax/sql and most probably also in core
> Felix, otherwise it wouldn't be possible the establish a pool.
>
> And now coming to the point: the "vanilla approach" works perfectly in
> the Servlet/JSP environment! I don't know in what context that part of
> Sling exactly runs, but the Driver class is seemingly found and DB
> interaction works.
> But from an architectural perspective, a JSP is obviously not the place
> where database code should be placed...
>
> Question is, how can access to the driver be achieved from an OSGi bundle?
>
> Best,
> Juerg
>
>
> On 26.02.21 18:13, Eric Norman wrote:
> > I'm not using JDBC datasources personally, but can you clarify in what
> > context your client code is running?
> >
> > In general the @Reference annotations (both the older felix.scr ones and
> > the newer standardardized annotations from OSGi R6 specification) are
> only
> > going to work when they are within a declarative service component and
> that
> > client class is accessed as an osgi service.
> >
> > If the client code is running in some other context or lookup of the
> client
> > class happens some other way, then you would likely need a different way
> to
> > get the reference to the DataSource component.
> >
> > For example, sling models can use the @Inject annotation for getting a
> > reference to an osgi service, or you can get the DataSource service
> > reference from a ServiceTracker or a direct service reference lookup from
> > some BundleContext.
> >
> > Regards,
> > Eric
> >
> > On Fri, Feb 26, 2021 at 7:04 AM JCR <j...@proxymit.net> wrote:
> >
> >> Adding a detail: The @Reference annotation is deprecated.
> >>
> >> ****************************
> >>
> >> For creating a JDBC connection pool (to mariadb) in Sling 11, I followed
> >> the instructions given at
> >>
> https://sling.apache.org/documentation/bundles/datasource-providers.html
> >> . However, I get a runtime exception on the datasource without further
> >> details.
> >>
> >> As documented on that webpage, I declared the following in the consuming
> >> class:
> >>
> >> import org.apache.felix.scr.annotations.Reference;
> >>
> >> public class Database {
> >>
> >> @Reference(target =
> >> "(&(objectclass=javax.sql.DataSource)(datasource.name=dbdb))")
> >> DataSource dataSource;
> >>
> >> public String test() {
> >>
> >> try {
> >>
> >> Connection con = dataSource.getConnection();
> >>
> >> ... Some SQL instructions...
> >>
> >> }
> >>
> >> The config of the datasource was done via the Felix console and looks
> like:
> >>
> >> in JNDI DataSource:
> >>
> >> Datasource name(*): dbdb
> >> JNDI name(*): dbdb
> >>
> >> in Apache Sling Connection Pooled DataSource:
> >>
> >> Datasource name(*): dbdb
> >> JDBC driver class: org.mariadb.jdbc.Driver
> >> JDBC connection URI:
> >>
> jdbc:mysql://localhost:3306/someDB?useUnicode=yes&characterEncoding=UTF-8
> >> Username: xyz
> >> .... many more
> >>
> >> The POM:
> >> <dependency>
> >> <groupId>org.apache.felix</groupId>
> >> <artifactId>org.apache.felix.scr.annotations</artifactId>
> >> <version>1.12.0</version>
> >> </dependency>
> >>
> >>
> >> Now, the datasource, at the moment of calling test() is null. I have
> >> absolutely no hint what the problem is. The config? The annotation? What
> >> is obvious, however, is that the /@Reference /as suggested on the
> >> bundles page, is deprecated... What would be the most current approach?
> >>
> >> Thanks,
> >> -Juerg
> >>
> >>
> >>
> >>
>
