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
  17 import org.apache.commons.io.IOUtils;
  18 import org.opendaylight.controller.config.spi.ModuleFactory;
  19 import org.osgi.framework.Bundle;
  20 import org.osgi.framework.BundleEvent;
  21 import org.osgi.framework.ServiceRegistration;
  22 import org.osgi.util.tracker.BundleTrackerCustomizer;
  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 ModuleFactoryBundleTracker implements BundleTrackerCustomizer<Object> {
  37     private final BlankTransactionServiceTracker blankTransactionServiceTracker;
  38     private static final Logger logger = LoggerFactory.getLogger(ModuleFactoryBundleTracker.class);
  39
  40     public ModuleFactoryBundleTracker(BlankTransactionServiceTracker blankTransactionServiceTracker) {
  41         this.blankTransactionServiceTracker = blankTransactionServiceTracker;
  42     }
  43
  44     @Override
  45     public Object addingBundle(Bundle bundle, BundleEvent event) {
  46         URL resource = bundle.getEntry("META-INF/services/" + ModuleFactory.class.getName());
  47         logger.trace("Got addingBundle event of bundle {}, resource {}, event {}",
  48                 bundle, resource, event);
  49         if (resource != null) {
  50             try (InputStream inputStream = resource.openStream()) {
  51                 List<String> lines = IOUtils.readLines(inputStream);
  52                 for (String factoryClassName : lines) {
  53                     registerFactory(factoryClassName, bundle);
  54                 }
  55             } catch (Exception e) {
  56                 logger.error("Error while reading {}", resource, e);
  57                 throw new RuntimeException(e);
  58             }
  59         }
  60         return bundle;
  61     }
  62
  63     @Override
  64     public void modifiedBundle(Bundle bundle, BundleEvent event, Object object) {
  65         // NOOP
  66     }
  67
  68     @Override
  69     public void removedBundle(Bundle bundle, BundleEvent event, Object object) {
  70         // workaround for service tracker not getting removed service event
  71         blankTransactionServiceTracker.blankTransaction();
  72     }
  73
  74     @VisibleForTesting
  75     protected static ServiceRegistration<?> registerFactory(String factoryClassName, Bundle bundle) {
  76         String errorMessage;
  77         Exception ex = null;
  78         try {
  79             Class<?> clazz = bundle.loadClass(factoryClassName);
  80             if (ModuleFactory.class.isAssignableFrom(clazz)) {
  81                 try {
  82                     logger.debug("Registering {} in bundle {}",
  83                             clazz.getName(), bundle);
  84                     return bundle.getBundleContext().registerService(
  85                             ModuleFactory.class.getName(), clazz.newInstance(),
  86                             null);
  87                 } catch (InstantiationException e) {
  88                     errorMessage = logMessage(
  89                             "Could not instantiate {} in bundle {}, reason {}",
  90                             factoryClassName, bundle, e);
  91                     ex = e;
  92                 } catch (IllegalAccessException e) {
  93                     errorMessage = logMessage(
  94                             "Illegal access during instantiation of class {} in bundle {}, reason {}",
  95                             factoryClassName, bundle, e);
  96                     ex = e;
  97                 }
  98             } else {
  99                 errorMessage = logMessage(
 100                         "Class {} does not implement {} in bundle {}", clazz,
 101                         ModuleFactory.class, bundle);
 102             }
 103         } catch (ClassNotFoundException e) {
 104             errorMessage = logMessage(
 105                     "Could not find class {} in bundle {}, reason {}",
 106                     factoryClassName, bundle, e);
 107             ex = e;
 108         }
 109
 110         throw ex == null ? new IllegalStateException(errorMessage) : new IllegalStateException(errorMessage, ex);
 111     }
 112
 113     public static String logMessage(String slfMessage, Object... params) {
 114         logger.info(slfMessage, params);
 115         String formatMessage = slfMessage.replaceAll("\\{\\}", "%s");
 116         return format(formatMessage, params);
 117     }
 118 }