org.apache.aries.util.AriesFrameworkUtil 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.aries.util;
import org.apache.aries.util.internal.DefaultWorker;
import org.apache.aries.util.internal.EquinoxWorker;
import org.apache.aries.util.internal.FelixWorker;
import org.apache.aries.util.internal.FrameworkUtilWorker;
import org.apache.aries.util.internal.R43Worker;
import org.osgi.framework.Bundle;
import org.osgi.framework.FrameworkUtil;
import org.osgi.framework.ServiceRegistration;
public final class AriesFrameworkUtil
{
private static FrameworkUtilWorker worker;
static {
try {
worker = new R43Worker();
} catch (Throwable e) {
}
Bundle b = FrameworkUtil.getBundle(AriesFrameworkUtil.class);
String bundleClassName = b == null? "": b.getClass().getName();
if (worker == null && isEquinox(bundleClassName)) {
worker = new EquinoxWorker();
} else if (worker == null && bundleClassName.startsWith("org.apache.felix")) {
worker = new FelixWorker();
}
if (worker == null || !!!worker.isValid()) worker = new DefaultWorker();
}
/**
* This method attempts to get the classloader for a bundle. It may return null if
* their is no such classloader, or if it cannot obtain the classloader for the bundle.
*
* @param b the bundle whose classloader is desired.
* @return the classloader if found, or null if for example the bundle is in INSTALLED or UNINSTALLED state
*/
public static ClassLoader getClassLoader(Bundle b)
{
if (b != null && b.getState() != Bundle.UNINSTALLED && b.getState() != Bundle.INSTALLED) {
return worker.getClassLoader(b);
} else {
return null;
}
}
/**
* Returns true if we are in equinox, and we can access the interfaces we need.
* @param bundleClassName the class name of the bundle implementation.
* @return true if we are in equinox, false otherwise.
*/
private static boolean isEquinox(String bundleClassName)
{
if (bundleClassName.startsWith("org.eclipse.osgi")) {
try {
Class.forName("org.eclipse.osgi.framework.internal.core.BundleHost");
return true;
} catch (ClassNotFoundException e) {
}
}
return false;
}
/**
* This method attempts to get the classloader for a bundle. It will force the creation
* of a classloader, so if no classloader exists. If the bundle is in installed state, but
* cannot be resolved the null will be returned.
*
* @param b the bundle to get a classloader for
* @return the classloader.
*/
public static ClassLoader getClassLoaderForced(Bundle b)
{
if (b == null)
return null;
try {
b.loadClass("java.lang.Object");
} catch (ClassNotFoundException e) {
}
return worker.getClassLoader(b);
}
/**
* Safely unregister the supplied ServiceRegistration, for when you don't
* care about the potential IllegalStateException and don't want
* it to run wild through your code
*
* @param reg The {@link ServiceRegistration}, may be null
*/
public static void safeUnregisterService(ServiceRegistration reg)
{
if(reg != null) {
try {
reg.unregister();
} catch (IllegalStateException e) {
//This can be safely ignored
}
}
}
}