opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/BeanToOsgiServiceManager.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 package org.opendaylight.controller.config.manager.impl.osgi;
   9
  10 import java.util.Dictionary;
  11 import java.util.HashSet;
  12 import java.util.Hashtable;
  13 import java.util.Set;
  14
  15 import org.opendaylight.controller.config.api.ModuleIdentifier;
  16 import org.opendaylight.controller.config.api.annotations.ServiceInterfaceAnnotation;
  17 import org.opendaylight.controller.config.manager.impl.util.InterfacesHelper;
  18 import org.opendaylight.controller.config.spi.Module;
  19 import org.osgi.framework.BundleContext;
  20 import org.osgi.framework.ServiceRegistration;
  21
  22 /**
  23  * Registers instantiated beans as OSGi services and unregisters these services
  24  * if beans are destroyed.
  25  */
  26 public class BeanToOsgiServiceManager {
  27     // name of properties submitted to osgi
  28     static final String INSTANCE_NAME_OSGI_PROP = "instanceName";
  29     static final String IMPLEMENTATION_NAME_OSGI_PROP = "implementationName";
  30
  31     private final BundleContext bundleContext;
  32
  33     public BeanToOsgiServiceManager(BundleContext context) {
  34         this.bundleContext = context;
  35     }
  36
  37     /**
  38      * To be called for every created, reconfigured and recreated config bean.
  39      * It is expected that before using this method OSGi service registry will
  40      * be cleaned from previous registrations.
  41      */
  42     public OsgiRegistration registerToOsgi(
  43             Class<? extends Module> configBeanClass, AutoCloseable instance,
  44             ModuleIdentifier moduleIdentifier) {
  45         try {
  46             final Set<Class<?>> configuresInterfaces = InterfacesHelper
  47                     .getOsgiRegistrationTypes(configBeanClass);
  48             checkInstanceImplementing(instance, configuresInterfaces);
  49
  50             // bundleContext.registerService blows up with empty 'clazzes'
  51             if (configuresInterfaces.isEmpty() == false) {
  52                 final Dictionary<String, ?> propertiesForOsgi = getPropertiesForOsgi(moduleIdentifier);
  53                 final ServiceRegistration<?> serviceRegistration = bundleContext
  54                         .registerService(classesToNames(configuresInterfaces), instance, propertiesForOsgi);
  55                 return new OsgiRegistration(serviceRegistration);
  56             } else {
  57                 return new OsgiRegistration();
  58             }
  59         } catch (IllegalStateException e) {
  60             throw new IllegalStateException(
  61                     "Error while registering instance into OSGi Service Registry: "
  62                             + moduleIdentifier, e);
  63         }
  64     }
  65
  66     private static String[] classesToNames(Set<Class<?>> cfgs) {
  67         String[] result = new String[cfgs.size()];
  68         int i = 0;
  69         for (Class<?> cfg : cfgs) {
  70             result[i] = cfg.getName();
  71             i++;
  72         }
  73         return result;
  74     }
  75
  76     private void checkInstanceImplementing(AutoCloseable instance,
  77             Set<Class<?>> configures) {
  78         Set<Class<?>> missing = new HashSet<>();
  79         for (Class<?> requiredIfc : configures) {
  80             if (requiredIfc.isInstance(instance) == false) {
  81                 missing.add(requiredIfc);
  82             }
  83         }
  84         if (missing.isEmpty() == false) {
  85             throw new IllegalStateException(
  86                     instance.getClass()
  87                             + " does not implement following interfaces as announced by "
  88                             + ServiceInterfaceAnnotation.class.getName()
  89                             + " annotation :" + missing);
  90         }
  91     }
  92
  93     private static Dictionary<String, ?> getPropertiesForOsgi(
  94             ModuleIdentifier moduleIdentifier) {
  95         Hashtable<String, String> table = new Hashtable<>();
  96         table.put(IMPLEMENTATION_NAME_OSGI_PROP,
  97                 moduleIdentifier.getFactoryName());
  98         table.put(INSTANCE_NAME_OSGI_PROP, moduleIdentifier.getInstanceName());
  99         return table;
 100     }
 101
 102     public static class OsgiRegistration implements AutoCloseable {
 103         private final ServiceRegistration<?> serviceRegistration;
 104
 105         public OsgiRegistration(ServiceRegistration<?> serviceRegistration) {
 106             this.serviceRegistration = serviceRegistration;
 107         }
 108
 109         public OsgiRegistration() {
 110             this.serviceRegistration = null;
 111         }
 112
 113         @Override
 114         public void close() {
 115             if (serviceRegistration != null) {
 116                 serviceRegistration.unregister();
 117             }
 118         }
 119     }
 120
 121 }