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 org.osgi.framework.BundleContext;
  12 import org.osgi.framework.ServiceRegistration;
  13 import org.osgi.util.tracker.BundleTracker;
  14 import org.osgi.util.tracker.ServiceTracker;
  15 import org.slf4j.Logger;
  16 import org.slf4j.LoggerFactory;
  17
  18 import java.util.ArrayList;
  19 import java.util.List;
  20 import java.util.ListIterator;
  21
  22 import static com.google.common.base.Preconditions.checkNotNull;
  23
  24 public class OsgiRegistrationUtil {
  25     private static final Logger logger = LoggerFactory.getLogger(OsgiRegistrationUtil.class);
  26
  27     @SafeVarargs
  28     public static <T> AutoCloseable registerService(BundleContext bundleContext, T service, Class<? super T> ... interfaces) {
  29         checkNotNull(service);
  30         checkNotNull(interfaces);
  31         List<AutoCloseable> autoCloseableList = new ArrayList<>();
  32         for (Class<? super T> ifc : interfaces) {
  33             ServiceRegistration<? super T> serviceRegistration = bundleContext.registerService(ifc, service, null);
  34             autoCloseableList.add(wrap(serviceRegistration));
  35         }
  36         return aggregate(autoCloseableList);
  37     }
  38
  39     public static AutoCloseable wrap(final ServiceRegistration<?> reg) {
  40         checkNotNull(reg);
  41         return new AutoCloseable() {
  42             @Override
  43             public void close() throws Exception {
  44                 reg.unregister();
  45             }
  46         };
  47     }
  48
  49     public static AutoCloseable wrap(final BundleTracker bundleTracker) {
  50         checkNotNull(bundleTracker);
  51         return new AutoCloseable() {
  52             @Override
  53             public void close() throws Exception {
  54                 bundleTracker.close();
  55             }
  56         };
  57     }
  58
  59     public static AutoCloseable wrap(final ServiceTracker<?, ?> serviceTracker) {
  60         checkNotNull(serviceTracker);
  61         return new AutoCloseable() {
  62             @Override
  63             public void close() throws Exception {
  64                 serviceTracker.close();
  65             }
  66         };
  67     }
  68
  69     /**
  70      * Close list of auto closeables in reverse order
  71      */
  72     public static AutoCloseable aggregate(final List<? extends AutoCloseable> list) {
  73         checkNotNull(list);
  74
  75         return new AutoCloseable() {
  76             @Override
  77             public void close() throws Exception {
  78                 Exception firstException = null;
  79                 for (ListIterator<? extends AutoCloseable> it = list.listIterator(list.size()); it.hasPrevious();) {
  80                     AutoCloseable ac = it.previous();
  81                     try {
  82                         ac.close();
  83                     } catch (Exception e) {
  84                         logger.warn("Exception while closing {}", ac, e);
  85                         if (firstException == null) {
  86                             firstException = e;
  87                         } else {
  88                             firstException.addSuppressed(e);
  89                         }
  90                     }
  91                 }
  92                 if (firstException != null) {
  93                     throw firstException;
  94                 }
  95             }
  96         };
  97     }
  98 }