/*
* Copyright 2009 Alin Dreghiciu.
*
* Licensed 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.ops4j.pax.swissbox.converter.java.util;
import static java.lang.String.*;
import java.util.Dictionary;
import java.util.Enumeration;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.SortedMap;
import java.util.TreeMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.osgi.service.blueprint.container.Converter;
import org.osgi.service.blueprint.container.ReifiedType;
import org.ops4j.pax.swissbox.converter.internal.Reflection;
import static org.ops4j.pax.swissbox.converter.java.lang.AssignableConverter.*;
import static org.ops4j.pax.swissbox.converter.java.lang.FromNullConverter.*;
/**
* JAVADOC
*
* NOTICE: This class contains code originally developed by "Apache Geronimo Project", OSGi Blueprint Implementation.
*
* @author <a href="mailto:dev@geronimo.apache.org">Apache Geronimo Project</a>
* @author Alin Dreghiciu (adreghiciu@gmail.com)
*/
public class ToMapConverter
implements Converter
{
private final Converter escape;
public ToMapConverter( final Converter escape )
{
this.escape = escape;
}
public boolean canConvert( final Object sourceObject,
final ReifiedType targetType )
{
return fromNullConverter().canConvert( sourceObject, targetType )
|| assignableConverter().canConvert( sourceObject, targetType )
|| Map.class.isAssignableFrom( targetType.getRawClass() )
&& ( sourceObject instanceof Map
|| sourceObject instanceof Dictionary );
}
public Object convert( final Object sourceObject,
final ReifiedType targetType )
throws Exception
{
if( !canConvert( sourceObject, targetType ) )
{
throw new Exception(
format(
"%s cannot convert an %s", ToMapConverter.class.getSimpleName(), sourceObject.getClass()
)
);
}
if( fromNullConverter().canConvert( sourceObject, targetType ) )
{
return fromNullConverter().convert( sourceObject, targetType );
}
if( assignableConverter().canConvert( sourceObject, targetType ) )
{
return assignableConverter().convert( sourceObject, targetType );
}
return convertToMap( sourceObject, targetType );
}
private Object convertToMap( final Object sourceObject,
final ReifiedType targetType )
throws Exception
{
final ReifiedType keyType = targetType.getActualTypeArgument( 0 );
final ReifiedType valueType = targetType.getActualTypeArgument( 1 );
if( sourceObject instanceof Dictionary )
{
final Map<Object, Object> converted = createMap( getMapType( targetType.getRawClass() ) );
final Dictionary toConvert = (Dictionary) sourceObject;
for( Enumeration keys = toConvert.keys(); keys.hasMoreElements(); )
{
final Object key = keys.nextElement();
try
{
converted.put(
escape.convert( key, keyType ),
escape.convert( toConvert.get( key ), valueType )
);
}
catch( Exception e )
{
throw new Exception(
format(
"Unable to convert from %s to %s (error converting map entry)", sourceObject, targetType
),
e
);
}
}
return converted;
}
if( sourceObject instanceof Map )
{
final Map<Object, Object> converted = createMap( getMapType( targetType.getRawClass() ) );
for( Map.Entry<?, ?> entry : ( (Map<?, ?>) sourceObject ).entrySet() )
{
try
{
converted.put(
escape.convert( entry.getKey(), keyType ),
escape.convert( entry.getValue(), valueType )
);
}
catch( Exception e )
{
throw new Exception(
format(
"Unable to convert from %s to %s (error converting map entry)", sourceObject, targetType
),
e
);
}
}
return converted;
}
throw new Exception( format( "Unable to convert from %s to %s", sourceObject, targetType ) );
}
private static Map<Object, Object> createMap( final Class<? extends Map> type )
throws Exception
{
return Reflection.newInstance( type );
}
private static Class<? extends Map> getMapType( final Class type )
{
if( Reflection.hasDefaultConstructor( type ) )
{
return type;
}
else if( SortedMap.class.isAssignableFrom( type ) )
{
return TreeMap.class;
}
else if( ConcurrentMap.class.isAssignableFrom( type ) )
{
return ConcurrentHashMap.class;
}
else
{
return LinkedHashMap.class;
}
}
public static ToMapConverter toMapConverter( final Converter escape )
{
return new ToMapConverter( escape );
}
}