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;
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();
final Bundle bundle = FrameworkUtil.getBundle(Objects.requireNonNull(lookupClass, "lookupClass"));
if (bundle != null) {
final BundleContext ctx = bundle.getBundleContext();
if (ctx == null) {
if (verbose) {
StatusLogger.getLogger()
.error(
"Unable to load OSGI services: The bundle has no valid BundleContext for serviceType = {}, lookup = {}, lookupClass = {}, bundle = {}",
serviceType,
lookup,
lookupClass,
bundle);
}
} else {
try {
return ctx.getServiceReferences(serviceType, null).stream().map(ctx::getService);
} catch (Throwable e) {
if (verbose) {
StatusLogger.getLogger().error("Unable to load OSGI services for service {}", serviceType, e);
}
}
}
}
return Stream.empty();
}
}