opendaylight/config/config-manager/src/main/java/org/opendaylight/controller/config/manager/impl/osgi/ModuleFactoryBundleTracker.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 com.google.common.annotations.VisibleForTesting;
  13 import java.io.InputStream;
  14 import java.net.URL;
  15 import java.util.List;
  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.BundleEvent;
  20 import org.osgi.framework.ServiceRegistration;
  21 import org.osgi.util.tracker.BundleTrackerCustomizer;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25
  26 /**
  27  * OSGi extender that listens for bundle activation events. Reads file
  28  * META-INF/services/org.opendaylight.controller.config.spi.ModuleFactory, each
  29  * line should contain an implementation of ModuleFactory interface. Creates new
  30  * instance with default constructor and registers it into OSGi service
  31  * registry. There is no need for listening for implementing removedBundle as
  32  * the services are unregistered automatically.
  33  * Code based on http://www.toedter.com/blog/?p=236
  34  */
  35 public class ModuleFactoryBundleTracker implements BundleTrackerCustomizer<Object> {
  36     private final BlankTransactionServiceTracker blankTransactionServiceTracker;
  37     private static final Logger LOG = LoggerFactory.getLogger(ModuleFactoryBundleTracker.class);
  38
  39     public ModuleFactoryBundleTracker(BlankTransactionServiceTracker blankTransactionServiceTracker) {
  40         this.blankTransactionServiceTracker = blankTransactionServiceTracker;
  41     }
  42
  43     @Override
  44     public Object addingBundle(Bundle bundle, BundleEvent event) {
  45         URL resource = bundle.getEntry("META-INF/services/" + ModuleFactory.class.getName());
  46         LOG.trace("Got addingBundle event of bundle {}, resource {}, event {}",
  47                 bundle, resource, event);
  48         if (resource != null) {
  49             try (InputStream inputStream = resource.openStream()) {
  50                 List<String> lines = IOUtils.readLines(inputStream);
  51                 for (String factoryClassName : lines) {
  52                     registerFactory(factoryClassName, bundle);
  53                 }
  54             } catch (Exception e) {
  55                 LOG.error("Error while reading {}", resource, e);
  56                 throw new RuntimeException(e);
  57             }
  58         }
  59         return bundle;
  60     }
  61
  62     @Override
  63     public void modifiedBundle(Bundle bundle, BundleEvent event, Object object) {
  64         // NOOP
  65     }
  66
  67     @Override
  68     public void removedBundle(Bundle bundle, BundleEvent event, Object object) {
  69         // workaround for service tracker not getting removed service event
  70         blankTransactionServiceTracker.blankTransaction();
  71     }
  72
  73     @VisibleForTesting
  74     protected static ServiceRegistration<?> registerFactory(String factoryClassName, Bundle bundle) {
  75         String errorMessage;
  76         Exception ex = null;
  77         try {
  78             Class<?> clazz = bundle.loadClass(factoryClassName);
  79             if (ModuleFactory.class.isAssignableFrom(clazz)) {
  80                 try {
  81                     LOG.debug("Registering {} in bundle {}",
  82                             clazz.getName(), bundle);
  83                     return bundle.getBundleContext().registerService(
  84                             ModuleFactory.class.getName(), clazz.newInstance(),
  85                             null);
  86                 } catch (InstantiationException e) {
  87                     errorMessage = logMessage(
  88                             "Could not instantiate {} in bundle {}, reason {}",
  89                             factoryClassName, bundle, e);
  90                     ex = e;
  91                 } catch (IllegalAccessException e) {
  92                     errorMessage = logMessage(
  93                             "Illegal access during instantiation of class {} in bundle {}, reason {}",
  94                             factoryClassName, bundle, e);
  95                     ex = e;
  96                 }
  97             } else {
  98                 errorMessage = logMessage(
  99                         "Class {} does not implement {} in bundle {}", clazz,
 100                         ModuleFactory.class, bundle);
 101             }
 102         } catch (ClassNotFoundException e) {
 103             errorMessage = logMessage(
 104                     "Could not find class {} in bundle {}, reason {}",
 105                     factoryClassName, bundle, e);
 106             ex = e;
 107         }
 108
 109         throw ex == null ? new IllegalStateException(errorMessage) : new IllegalStateException(errorMessage, ex);
 110     }
 111
 112     public static String logMessage(String slfMessage, Object... params) {
 113         LOG.info(slfMessage, params);
 114         String formatMessage = slfMessage.replaceAll("\\{\\}", "%s");
 115         return format(formatMessage, params);
 116     }
 117 }