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/*
Calimero 2 - A library for KNX network access
Copyright (c) 2022, 2024 B. Malinowsky
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.
As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under terms
of your choice, provided that you also meet, for each linked independent
module, the terms and conditions of the license of that module. An
independent module is a module which is not derived from or based on
this library. If you modify this library, you may extend this exception
to your version of the library, but you are not obligated to do so. If
you do not wish to do so, delete this exception statement from your
version.
*/
package tuwien.auto.calimero.serial;
import java.io.IOException;
import java.util.Objects;
import java.util.Optional;
import java.util.ServiceLoader;
import java.util.ServiceLoader.Provider;
import java.util.concurrent.atomic.AtomicReference;
import java.util.stream.Stream;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import tuwien.auto.calimero.KNXException;
/**
* Internal use only.
*
* @param Connection provider
* @param Connection
*/
public final class ConnectionFactory {
private static final Logger logger = LoggerFactory.getLogger("tuwien.auto.calimero.serial");
private final ServiceLoader sl;
private final String svcName;
public interface ThrowingFunction {
C open(P provider) throws KNXException, IOException;
}
public ConnectionFactory(final Class service) {
sl = ServiceLoader.load(service);
svcName = service.getName();
}
public C open(final ThrowingFunction openFunc) throws KNXException, IOException {
final var tref = new AtomicReference();
final var optC = providers().map(provider -> {
try {
final var conn = openFunc.open(provider);
logger.debug("{} port setup: {}", provider, conn);
return Optional.of(conn);
}
catch (KNXException | IOException | RuntimeException t) {
tref.set(t);
return Optional.empty();
}
}).flatMap(Optional::stream).findFirst();
if (optC.isPresent())
return optC.get();
final var t = tref.get();
if (t == null)
throw new KNXException("no service provider available for " + svcName);
if (t instanceof KNXException exception)
throw exception;
if (t instanceof IOException exception)
throw exception;
throw new KNXException("failed to open connection", t);
}
public Stream providers() {
return providers(true).map(provider -> {
try {
logger.trace("instantiate service provider {}", provider.type().getName());
return provider.get();
}
catch (final Throwable e) { // handles ServiceConfigurationError
final var ex = e.getCause() != null ? e.getCause() : e;
logger.debug("skip service provider {}: {}", provider.type().getName(), ex.getMessage());
}
return null;
}).filter(Objects::nonNull);
}
private Stream> providers(final boolean refresh) {
if (refresh)
sl.reload();
return sl.stream();
}
}