com.mchange.v3.decode.DecodeUtils Maven / Gradle / Ivy
/*
* Distributed as part of mchange-commons-java 0.2.11
*
* Copyright (C) 2015 Machinery For Change, Inc.
*
* Author: Steve Waldman
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of EITHER:
*
* 1) The GNU Lesser General Public License (LGPL), version 2.1, as
* published by the Free Software Foundation
*
* OR
*
* 2) The Eclipse Public License (EPL), version 1.0
*
* You may choose which license to accept if you wish to redistribute
* or modify this work. You may offer derivatives of this work
* under the license you have chosen, or you may provide the same
* choice of license which you have been offered here.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
*
* You should have received copies of both LGPL v2.1 and EPL v1.0
* along with this software; see the files LICENSE-EPL and LICENSE-LGPL.
* If not, the text of these licenses are currently available at
*
* LGPL v2.1: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html
* EPL v1.0: http://www.eclipse.org/org/documents/epl-v10.php
*
*/
package com.mchange.v3.decode;
import java.util.*;
import java.lang.reflect.*;
import com.mchange.v2.log.*;
public final class DecodeUtils
{
public final static String DECODER_CLASS_DOT_KEY = ".decoderClass";
public final static String DECODER_CLASS_NO_DOT_KEY = "decoderClass";
private final static Object[] DECODER_CLASS_DOT_KEY_OBJ_ARRAY = new Object[] { DECODER_CLASS_DOT_KEY };
private final static Object[] DECODER_CLASS_NO_DOT_KEY_OBJ_ARRAY = new Object[] { DECODER_CLASS_NO_DOT_KEY };
private final static MLogger logger = MLog.getLogger( DecodeUtils.class );
private final static List finders;
private final static String[] finderClassNames = {
"com.mchange.sc.v1.decode.ScalaMapDecoderFinder"
};
static
{
List tmp = new LinkedList();
tmp.add( new JavaMapDecoderFinder() );
for ( int i = 0, len = finderClassNames.length; i < len; ++i )
{
try { tmp.add( (DecoderFinder) Class.forName( finderClassNames[i] ).newInstance() ); }
catch( Exception e )
{
if ( logger.isLoggable( MLevel.INFO ) )
logger.log( MLevel.INFO, "Could not load DecoderFinder '" + finderClassNames[i] + "'", e );
}
}
finders = Collections.unmodifiableList( tmp );
}
static class JavaMapDecoderFinder implements DecoderFinder
{
public String decoderClassName( Object encoded ) throws CannotDecodeException
{
if ( encoded instanceof Map )
{
String className = null;
Map map = (Map) encoded;
className = (String) map.get( DECODER_CLASS_DOT_KEY );
if ( className == null )
className = (String) map.get( DECODER_CLASS_NO_DOT_KEY );
if ( className == null )
throw new CannotDecodeException( "Could not find the decoder class for java.util.Map: " + encoded );
else
return className;
}
else
return null;
}
}
final static String findDecoderClassName( Object encoded ) throws CannotDecodeException
{
for ( DecoderFinder finder : finders )
{
String check = finder.decoderClassName( encoded );
if ( check != null ) return check;
}
throw new CannotDecodeException("Could not find a decoder class name for object: " + encoded);
}
public static Object decode( String decoderClassFqcn, Object encoded ) throws CannotDecodeException
{
try
{
Class clz = Class.forName( decoderClassFqcn );
Decoder decoder = (Decoder) clz.newInstance();
return decoder.decode( encoded );
}
catch ( Exception e )
{ throw new CannotDecodeException("An exception occurred while attempting to decode " + encoded, e); }
}
public static Object decode( Object encoded ) throws CannotDecodeException
{ return decode( findDecoderClassName( encoded ), encoded ); }
private DecodeUtils()
{}
}