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