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 import java.util.ArrayList;
  13 import java.util.List;
  14 import java.util.ListIterator;
  15 import org.osgi.framework.BundleContext;
  16 import org.osgi.framework.ServiceRegistration;
  17 import org.osgi.util.tracker.BundleTracker;
  18 import org.osgi.util.tracker.ServiceTracker;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21
  22 public class OsgiRegistrationUtil {
  23     private static final Logger LOGGER = LoggerFactory.getLogger(OsgiRegistrationUtil.class);
  24
  25     private OsgiRegistrationUtil() {
  26     }
  27
  28     @SafeVarargs
  29     public static <T> AutoCloseable registerService(final BundleContext bundleContext, final T service, final Class<? super T> ... interfaces) {
  30         checkNotNull(service);
  31         checkNotNull(interfaces);
  32         List<AutoCloseable> autoCloseableList = new ArrayList<>();
  33         for (Class<? super T> ifc : interfaces) {
  34             ServiceRegistration<? super T> serviceRegistration = bundleContext.registerService(ifc, service, null);
  35             autoCloseableList.add(wrap(serviceRegistration));
  36         }
  37         return aggregate(autoCloseableList);
  38     }
  39
  40     public static AutoCloseable wrap(final ServiceRegistration<?> reg) {
  41         checkNotNull(reg);
  42         return new AutoCloseable() {
  43             @Override
  44             public void close() throws Exception {
  45                 reg.unregister();
  46             }
  47         };
  48     }
  49
  50     public static AutoCloseable wrap(final BundleTracker<?> bundleTracker) {
  51         checkNotNull(bundleTracker);
  52         return new AutoCloseable() {
  53             @Override
  54             public void close() throws Exception {
  55                 bundleTracker.close();
  56             }
  57         };
  58     }
  59
  60     public static AutoCloseable wrap(final ServiceTracker<?, ?> serviceTracker) {
  61         checkNotNull(serviceTracker);
  62         return new AutoCloseable() {
  63             @Override
  64             public void close() throws Exception {
  65                 serviceTracker.close();
  66             }
  67         };
  68     }
  69
  70     /**
  71      * Close list of auto closeables in reverse order
  72      */
  73     public static AutoCloseable aggregate(final List<? extends AutoCloseable> list) {
  74         checkNotNull(list);
  75
  76         return new AutoCloseable() {
  77             @Override
  78             public void close() throws Exception {
  79                 Exception firstException = null;
  80                 for (ListIterator<? extends AutoCloseable> it = list.listIterator(list.size()); it.hasPrevious();) {
  81                     AutoCloseable ac = it.previous();
  82                     try {
  83                         ac.close();
  84                     } catch (Exception e) {
  85                         LOGGER.warn("Exception while closing {}", ac, e);
  86                         if (firstException == null) {
  87                             firstException = e;
  88                         } else {
  89                             firstException.addSuppressed(e);
  90                         }
  91                     }
  92                 }
  93                 if (firstException != null) {
  94                     throw firstException;
  95                 }
  96             }
  97         };
  98     }
  99 }