opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/ExtenderBundleTracker.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 static java.lang.String.format;
  11
  12 import java.io.InputStream;
  13 import java.net.URL;
  14 import java.util.List;
  15
  16 import org.apache.commons.io.IOUtils;
  17 import org.opendaylight.controller.config.spi.ModuleFactory;
  18 import org.osgi.framework.Bundle;
  19 import org.osgi.framework.BundleContext;
  20 import org.osgi.framework.BundleEvent;
  21 import org.osgi.framework.ServiceRegistration;
  22 import org.osgi.util.tracker.BundleTracker;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26
  27 /**
  28  * OSGi extender that listens for bundle activation events. Reads file
  29  * META-INF/services/org.opendaylight.controller.config.spi.ModuleFactory, each
  30  * line should contain an implementation of ModuleFactory interface. Creates new
  31  * instance with default constructor and registers it into OSGi service
  32  * registry. There is no need for listening for implementing removedBundle as
  33  * the services are unregistered automatically.
  34  * Code based on http://www.toedter.com/blog/?p=236
  35  */
  36 public class ExtenderBundleTracker extends BundleTracker<Object> {
  37     private final BlankTransactionServiceTracker blankTransactionServiceTracker;
  38     private static final Logger logger = LoggerFactory.getLogger(ExtenderBundleTracker.class);
  39
  40     public ExtenderBundleTracker(BundleContext context, BlankTransactionServiceTracker blankTransactionServiceTracker) {
  41         super(context, Bundle.ACTIVE, null);
  42         this.blankTransactionServiceTracker = blankTransactionServiceTracker;
  43         logger.trace("Registered as extender with context {}", context);
  44     }
  45
  46     @Override
  47     public Object addingBundle(Bundle bundle, BundleEvent event) {
  48         URL resource = bundle.getEntry("META-INF/services/" + ModuleFactory.class.getName());
  49         logger.trace("Got addingBundle event of bundle {}, resource {}, event {}",
  50                 bundle, resource, event);
  51         if (resource != null) {
  52             try (InputStream inputStream = resource.openStream()) {
  53                 List<String> lines = IOUtils.readLines(inputStream);
  54                 for (String factoryClassName : lines) {
  55                     registerFactory(factoryClassName, bundle);
  56                 }
  57             } catch (Exception e) {
  58                 logger.error("Error while reading {}", resource, e);
  59                 throw new RuntimeException(e);
  60             }
  61         }
  62         return bundle;
  63     }
  64
  65     @Override
  66     public void removedBundle(Bundle bundle, BundleEvent event, Object object) {
  67         super.removedBundle(bundle,event,object);
  68         // workaround for service tracker not getting removed service event
  69         blankTransactionServiceTracker.blankTransaction();
  70     }
  71
  72     // TODO:test
  73     private static ServiceRegistration<?> registerFactory(String factoryClassName, Bundle bundle) {
  74         String errorMessage;
  75         try {
  76             Class<?> clazz = bundle.loadClass(factoryClassName);
  77             if (ModuleFactory.class.isAssignableFrom(clazz)) {
  78                 try {
  79                     logger.debug("Registering {} in bundle {}",
  80                             clazz.getName(), bundle);
  81                     return bundle.getBundleContext().registerService(
  82                             ModuleFactory.class.getName(), clazz.newInstance(),
  83                             null);
  84                 } catch (InstantiationException e) {
  85                     errorMessage = logMessage(
  86                             "Could not instantiate {} in bundle {}, reason {}",
  87                             factoryClassName, bundle, e);
  88                 } catch (IllegalAccessException e) {
  89                     errorMessage = logMessage(
  90                             "Illegal access during instatiation of class {} in bundle {}, reason {}",
  91                             factoryClassName, bundle, e);
  92                 }
  93             } else {
  94                 errorMessage = logMessage(
  95                         "Class {} does not implement {} in bundle {}", clazz,
  96                         ModuleFactory.class, bundle);
  97             }
  98         } catch (ClassNotFoundException e) {
  99             errorMessage = logMessage(
 100                     "Could not find class {} in bunde {}, reason {}",
 101                     factoryClassName, bundle, e);
 102         }
 103         throw new IllegalStateException(errorMessage);
 104     }
 105
 106     public static String logMessage(String slfMessage, Object... params) {
 107         logger.info(slfMessage, params);
 108         String formatMessage = slfMessage.replaceAll("\\{\\}", "%s");
 109         return format(formatMessage, params);
 110     }
 111 }