org.apache.logging.log4j.util.OsgiServiceLocator Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to you under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.logging.log4j.util;
import java.lang.invoke.MethodHandles.Lookup;
import java.util.Objects;
import java.util.stream.Stream;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.status.StatusLogger;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.wiring.BundleRevision;
public class OsgiServiceLocator {
private static final Logger LOGGER = StatusLogger.getLogger();
private static final boolean OSGI_AVAILABLE = checkOsgiAvailable();
private static boolean checkOsgiAvailable() {
try {
/*
* OSGI classes of any version can still be present even if Log4j2 does not run in
* an OSGI container, hence we check if this class is in a bundle.
*/
final Class clazz = Class.forName("org.osgi.framework.FrameworkUtil");
return clazz.getMethod("getBundle", Class.class).invoke(null, OsgiServiceLocator.class) != null;
} catch (final ClassNotFoundException | NoSuchMethodException | LinkageError e) {
return false;
} catch (final Throwable error) {
LOGGER.error("Unknown error checking OSGI environment.", error);
return false;
}
}
public static boolean isAvailable() {
return OSGI_AVAILABLE;
}
public static Stream loadServices(final Class serviceType, final Lookup lookup) {
return loadServices(serviceType, lookup, true);
}
public static Stream loadServices(final Class serviceType, final Lookup lookup, final boolean verbose) {
final Class lookupClass = Objects.requireNonNull(lookup, "lookup").lookupClass();
return loadServices(serviceType, lookupClass, StatusLogger.getLogger());
}
static Stream loadServices(final Class serviceType, final Class callerClass, final Logger logger) {
final Bundle bundle = FrameworkUtil.getBundle(callerClass);
if (bundle != null && !isFragment(bundle)) {
final BundleContext ctx = bundle.getBundleContext();
if (ctx == null) {
logger.warn(
"Unable to load OSGi services for service {}: bundle {} (state {}) does not have a valid BundleContext",
serviceType::getName,
bundle::getSymbolicName,
() -> {
switch (bundle.getState()) {
case Bundle.UNINSTALLED:
return "UNINSTALLED";
case Bundle.INSTALLED:
return "INSTALLED";
case Bundle.RESOLVED:
return "RESOLVED";
case Bundle.STARTING:
return "STARTING";
case Bundle.STOPPING:
return "STOPPING";
case Bundle.ACTIVE:
return "ACTIVE";
default:
return "UNKNOWN";
}
});
} else {
try {
return ctx.getServiceReferences(serviceType, null).stream().map(ctx::getService);
} catch (final Exception e) {
logger.error("Unable to load OSGI services for service {}", serviceType, e);
}
}
}
return Stream.empty();
}
private static boolean isFragment(final Bundle bundle) {
try {
return (bundle.adapt(BundleRevision.class).getTypes() & BundleRevision.TYPE_FRAGMENT) != 0;
} catch (final SecurityException ignored) {
return false;
}
}
}