/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.felix.metatype.internal;
import java.io.PrintStream;
import java.text.SimpleDateFormat;
import java.util.*;
import org.apache.felix.metatype.internal.l10n.BundleResources;
import org.osgi.framework.*;
import org.osgi.service.log.LogService;
import org.osgi.service.metatype.MetaTypeService;
import org.osgi.util.tracker.ServiceTracker;
/**
* The <code>Activator</code> class is the <code>BundleActivator</code> of
* this bundle and provides abstract logging functionality: If a
* <code>LogService</code> is available, that service is used, otherwise
* logging goes to standard output or standard error (in case of level ERROR
* messages).
*
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
public class Activator implements BundleActivator
{
/** The name of the log service. */
private static final String NAME_LOG_SERVICE = LogService.class.getName();
/**
* A <code>SimpleDateFormat</code> object to format the a log message time
* stamp in case of logging to standard output/error (value of format
* pattern is "dd.MM.yyyy HH:mm:ss").
*/
private static final SimpleDateFormat FORMAT = new SimpleDateFormat( "dd.MM.yyyy HH:mm:ss" );
/**
* The (singleton) instance of this activator. Used by the log methods to
* access the {@link #logService} field.
*/
private static Activator INSTANCE;
/**
* The <code>LogService</code> used to log messages. If a log service is
* not available in the framework, this field is <code>null</code>.
*
* @see #start(BundleContext)
* @see #serviceChanged(ServiceEvent)
*/
private ServiceTracker logService;
/*
* Set the static INSTANCE field to this new instance
*/
{
INSTANCE = this;
}
/**
* Starts this bundle doing the following:
* <ol>
* <li>Register as listener for service events concerning the
* <code>LogService</code>
* <li>Try to get the <code>LogService</code>
* <li>Registers the <code>MetaTypeService</code> implementation provided
* by this bundle.
* </ol>
*
* @param context The <code>BundleContext</code> of this activator's bundle
*/
public void start( BundleContext context )
{
// register for log service events
logService = new ServiceTracker( context, NAME_LOG_SERVICE, null );
logService.open();
// register the MetaTypeService now, that we are ready
Dictionary props = new Hashtable();
props.put( Constants.SERVICE_PID, "org.apache.felix.metatype.MetaTypeService" );
props.put( Constants.SERVICE_DESCRIPTION, "MetaTypeService Specification 1.2 Implementation" );
props.put( Constants.SERVICE_VENDOR, "Apache Software Foundation" );
MetaTypeService metaTypeService = new MetaTypeServiceImpl( context );
context.registerService( MetaTypeService.class.getName(), metaTypeService, props );
}
/**
* Stops this bundle by just unregistering as a service listener.
* <p>
* The framework will take care of ungetting the <code>LogService</code> and
* unregistering the <code>MetaTypeService</code> registered by the
* {@link #start(BundleContext)} method.
*
* @param context The <code>BundleContext</code> of this activator's bundle
*/
public void stop( BundleContext context )
{
logService.close();
// make sure the static BundleResources cache does not block the class laoder
BundleResources.clearResourcesCache();
}
//---------- Logging Support ----------------------------------------------
// log to stdout or use LogService
public static void log( int level, String message )
{
LogService log = ( LogService ) INSTANCE.logService.getService();
if ( log == null )
{
_log( null, level, message, null );
}
else
{
log.log( level, message );
}
}
public static void log( int level, String message, Throwable exception )
{
LogService log = ( LogService ) INSTANCE.logService.getService();
if ( log == null )
{
_log( null, level, message, exception );
}
else
{
log.log( level, message, exception );
}
}
public static void log( ServiceReference sr, int level, String message )
{
LogService log = ( LogService ) INSTANCE.logService.getService();
if ( log == null )
{
_log( sr, level, message, null );
}
else
{
log.log( sr, level, message );
}
}
public static void log( ServiceReference sr, int level, String message, Throwable exception )
{
LogService log = ( LogService ) INSTANCE.logService.getService();
if ( log == null )
{
_log( sr, level, message, exception );
}
else
{
log.log( sr, level, message, exception );
}
}
//---------- Helper Methods -----------------------------------------------
private static void _log( ServiceReference sr, int level, String message, Throwable exception )
{
String time = getTimeStamp();
StringBuffer buf = new StringBuffer( time );
buf.append( ' ' ).append( toLevelString( level ) ).append( ' ' );
buf.append( message );
if ( sr != null )
{
final String name;
String[] pids = BaseProviderHolder.getServicePids( sr );
if ( pids != null )
{
name = pids[0];
}
else
{
name = ( ( String[] ) sr.getProperty( Constants.OBJECTCLASS ) )[0];
}
buf.append( " (" ).append( name ).append( ", service.id=" ).append( sr.getProperty( Constants.SERVICE_ID ) )
.append( ')' );
}
PrintStream dst = ( level == LogService.LOG_ERROR ) ? System.err : System.out;
dst.println( buf );
if ( exception != null )
{
buf = new StringBuffer( time );
buf.append( ' ' ).append( toLevelString( level ) ).append( ' ' );
dst.print( buf );
exception.printStackTrace( dst );
}
}
private static String getTimeStamp()
{
synchronized ( FORMAT )
{
return FORMAT.format( new Date() );
}
}
private static String toLevelString( int level )
{
switch ( level )
{
case LogService.LOG_DEBUG:
return "*DEBUG*";
case LogService.LOG_INFO:
return "*INFO *";
case LogService.LOG_WARNING:
return "*WARN *";
case LogService.LOG_ERROR:
return "*ERROR*";
default:
return "*" + level + "*";
}
}
}