opendaylight/logging/bridge/src/main/java/org/opendaylight/controller/logging/bridge/internal/Activator.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.logging.bridge.internal;
   9
  10 import org.osgi.service.log.LogEntry;
  11
  12 import java.lang.Thread.UncaughtExceptionHandler;
  13 import java.util.Enumeration;
  14
  15 import org.osgi.framework.BundleContext;
  16 import org.osgi.framework.BundleException;
  17 import org.osgi.framework.BundleActivator;
  18 import org.osgi.framework.ServiceReference;
  19 import org.slf4j.Logger;
  20 import org.slf4j.LoggerFactory;
  21 import org.slf4j.ILoggerFactory;
  22 import org.osgi.service.log.LogReaderService;
  23
  24 public class Activator implements BundleActivator {
  25     private static final String UNCAUGHT_EXCEPTION_POLICY_PROP = "controller.uncaughtExceptionPolicy";
  26     private static final UncaughtExceptionPolicy DEFAULT_UNCAUGHT_EXCEPTION_POLICY = UncaughtExceptionPolicy.IGNORE;
  27
  28     private LogListenerImpl listener = null;
  29     private ShutdownHandler shutdownHandler = null;
  30     private Logger log = null;
  31
  32     @Override
  33     public void start(BundleContext context) {
  34         // Lets trigger the resolution of the slf4j logger factory
  35         ILoggerFactory f = LoggerFactory.getILoggerFactory();
  36
  37         // Now retrieve a logger for the bridge
  38         log = f
  39                 .getLogger("org.opendaylight.controller.logging.bridge.OSGI2SLF4J");
  40
  41         if (this.log != null) {
  42             this.listener = new LogListenerImpl(log);
  43
  44             ServiceReference service = null;
  45             service = context.getServiceReference(LogReaderService.class
  46                     .getName());
  47             if (service != null) {
  48                 LogReaderService reader = (LogReaderService) context
  49                         .getService(service);
  50                 if (reader == null) {
  51                     this.log.error("Cannot register the LogListener because "
  52                             + "cannot retrieve LogReaderService");
  53                 }
  54                 reader.addLogListener(this.listener);
  55                 // Now lets walk all the exiting messages
  56                 Enumeration<LogEntry> entries = reader.getLog();
  57                 if (entries != null) {
  58                     while (entries.hasMoreElements()) {
  59                         LogEntry entry = (LogEntry) entries.nextElement();
  60                         this.listener.logged(entry);
  61                     }
  62                 }
  63
  64                 /*
  65                  * Install the default exception handler so that the uncaught
  66                  * exceptions are handled by our customized handler. This new
  67                  * handler will display the exceptions to OSGI console as well
  68                  * as log to file.
  69                  */
  70                 UncaughtExceptionHandler handler = DEFAULT_UNCAUGHT_EXCEPTION_POLICY;
  71                 final String policy = context.getProperty(UNCAUGHT_EXCEPTION_POLICY_PROP);
  72                 if (policy != null) {
  73                     try {
  74                         handler = UncaughtExceptionPolicy.valueOf(policy.toUpperCase());
  75                     } catch (IllegalArgumentException ex) {
  76                         log.warn("Invalid policy name \"{}\", defaulting to {}", policy, handler);
  77                     }
  78                 }
  79                 log.trace("Setting uncaught exception policy to {}", handler);
  80                 Thread.setDefaultUncaughtExceptionHandler(handler);
  81
  82                 /*
  83                  * Install the Shutdown handler. This will intercept SIGTERM signal and
  84                  * close the system bundle. This allows for a graceful  closing of OSGI
  85                  * framework.
  86                  */
  87                 shutdownHandler = new ShutdownHandler(context);
  88                 Runtime.getRuntime().addShutdownHook(shutdownHandler);
  89             } else {
  90                 this.log.error("Cannot register the LogListener because "
  91                         + "cannot retrieve LogReaderService");
  92             }
  93         } else {
  94             System.err
  95                     .println("Could not initialize the logging bridge subsytem");
  96         }
  97     }
  98
  99     @Override
 100     public void stop(BundleContext context) {
 101         ServiceReference service = null;
 102         service = context.getServiceReference(LogReaderService.class.getName());
 103         if (service != null) {
 104             LogReaderService reader = (LogReaderService) service;
 105             reader.removeLogListener(this.listener);
 106         }
 107         if (this.shutdownHandler != null) {
 108             Runtime.getRuntime().removeShutdownHook(this.shutdownHandler);
 109         }
 110         this.listener = null;
 111         this.log = null;
 112         this.shutdownHandler = null;
 113     }
 114
 115     private class ShutdownHandler extends Thread {
 116         BundleContext bundlecontext;
 117         public ShutdownHandler(BundleContext ctxt) {
 118                 this.bundlecontext = ctxt;
 119         }
 120
 121         @Override
 122         public void run () {
 123             try {
 124                 this.bundlecontext.getBundle(0).stop();
 125                 log.debug("shutdown handler thread called");
 126             } catch (BundleException e) {
 127                 log.debug("Bundle couldn't be stopped");
 128             } catch (Exception e) {
 129                 log.debug("Unhandled exception");
 130             }
 131         }
 132     }
 133
 134 }