opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/util/OsgiRegistrationUtil.java

   1 /*
   2  * Copyright (c) 2013 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8
   9 package org.opendaylight.controller.config.manager.impl.util;
  10
  11 import static com.google.common.base.Preconditions.checkNotNull;
  12
  13 import java.util.ArrayList;
  14 import java.util.List;
  15 import java.util.ListIterator;
  16 import org.osgi.framework.BundleContext;
  17 import org.osgi.framework.ServiceRegistration;
  18 import org.osgi.util.tracker.BundleTracker;
  19 import org.osgi.util.tracker.ServiceTracker;
  20 import org.slf4j.Logger;
  21 import org.slf4j.LoggerFactory;
  22
  23 public class OsgiRegistrationUtil {
  24     private static final Logger LOGGER = LoggerFactory.getLogger(OsgiRegistrationUtil.class);
  25
  26     private OsgiRegistrationUtil() {
  27     }
  28
  29     @SafeVarargs
  30     public static <T> AutoCloseable registerService(BundleContext bundleContext, T service, Class<? super T> ... interfaces) {
  31         checkNotNull(service);
  32         checkNotNull(interfaces);
  33         List<AutoCloseable> autoCloseableList = new ArrayList<>();
  34         for (Class<? super T> ifc : interfaces) {
  35             ServiceRegistration<? super T> serviceRegistration = bundleContext.registerService(ifc, service, null);
  36             autoCloseableList.add(wrap(serviceRegistration));
  37         }
  38         return aggregate(autoCloseableList);
  39     }
  40
  41     public static AutoCloseable wrap(final ServiceRegistration<?> reg) {
  42         checkNotNull(reg);
  43         return new AutoCloseable() {
  44             @Override
  45             public void close() throws Exception {
  46                 reg.unregister();
  47             }
  48         };
  49     }
  50
  51     public static AutoCloseable wrap(final BundleTracker bundleTracker) {
  52         checkNotNull(bundleTracker);
  53         return new AutoCloseable() {
  54             @Override
  55             public void close() throws Exception {
  56                 bundleTracker.close();
  57             }
  58         };
  59     }
  60
  61     public static AutoCloseable wrap(final ServiceTracker<?, ?> serviceTracker) {
  62         checkNotNull(serviceTracker);
  63         return new AutoCloseable() {
  64             @Override
  65             public void close() throws Exception {
  66                 serviceTracker.close();
  67             }
  68         };
  69     }
  70
  71     /**
  72      * Close list of auto closeables in reverse order
  73      */
  74     public static AutoCloseable aggregate(final List<? extends AutoCloseable> list) {
  75         checkNotNull(list);
  76
  77         return new AutoCloseable() {
  78             @Override
  79             public void close() throws Exception {
  80                 Exception firstException = null;
  81                 for (ListIterator<? extends AutoCloseable> it = list.listIterator(list.size()); it.hasPrevious();) {
  82                     AutoCloseable ac = it.previous();
  83                     try {
  84                         ac.close();
  85                     } catch (Exception e) {
  86                         LOGGER.warn("Exception while closing {}", ac, e);
  87                         if (firstException == null) {
  88                             firstException = e;
  89                         } else {
  90                             firstException.addSuppressed(e);
  91                         }
  92                     }
  93                 }
  94                 if (firstException != null) {
  95                     throw firstException;
  96                 }
  97             }
  98         };
  99     }
 100 }