/*
* 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.sling.junit.rules;
import org.apache.sling.junit.Activator;
import org.junit.rules.TestRule;
import org.junit.runner.Description;
import org.junit.runners.model.Statement;
import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
/**
* Allows a test class to obtain a reference to an OSGi service. This rule embodies the logic to get a bundle context,
* obtain a service reference, fetch the reference to the object and perform the proper cleanup after the test has run.
*/
public class Service implements TestRule {
private final Class<?> serviceClass;
private Object service;
public Service(Class<?> serviceClass) {
this.serviceClass = serviceClass;
}
public Statement apply(final Statement base, final Description description) {
return new Statement() {
@Override
public void evaluate() throws Throwable {
final BundleContext bundleContext = Activator.getBundleContext();
if (bundleContext == null) {
throw new IllegalStateException("unable to obtain a bundle context");
}
final ServiceReference serviceReference = bundleContext.getServiceReference(serviceClass.getName());
if (serviceReference == null) {
throw new IllegalStateException("unable to get a service reference");
}
final Object service = bundleContext.getService(serviceReference);
if (service == null) {
throw new IllegalStateException("unable to get an instance of the service");
}
Service.this.service = serviceClass.cast(service);
try {
base.evaluate();
} finally {
Service.this.service = null;
bundleContext.ungetService(serviceReference);
}
}
};
}
/**
* Return the service object.
*
* @param serviceClass Use this class to perform a cast before the object is returned.
* @param <T> The type of the service.
* @return The service object.
*/
public <T> T getService(Class<T> serviceClass) {
return serviceClass.cast(service);
}
}