001    /*
002      GRANITE DATA SERVICES
003      Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004    
005      This file is part of Granite Data Services.
006    
007      Granite Data Services is free software; you can redistribute it and/or modify
008      it under the terms of the GNU Library General Public License as published by
009      the Free Software Foundation; either version 2 of the License, or (at your
010      option) any later version.
011    
012      Granite Data Services is distributed in the hope that it will be useful, but
013      WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014      FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015      for more details.
016    
017      You should have received a copy of the GNU Library General Public License
018      along with this library; if not, see <http://www.gnu.org/licenses/>.
019    */
020    
021    package org.granite.messaging.amf.io.util.instantiator;
022    
023    import java.util.ArrayList;
024    import java.util.Collections;
025    import java.util.List;
026    
027    import org.granite.messaging.service.ServiceException;
028    import org.granite.util.ClassUtil;
029    
030    /**
031     * @author Igor SAZHNEV
032     */
033    public class EnumInstantiator extends AbstractInstantiator<Enum<?>> {
034    
035        private static final long serialVersionUID = -6116814787518316453L;
036    
037        private final String type;
038    
039        private static final List<String> orderedFields;
040        static {
041            List<String> of = new ArrayList<String>(1);
042            of.add("value");
043            orderedFields = Collections.unmodifiableList(of);
044        }
045    
046        public EnumInstantiator(String type) {
047            this.type = type;
048        }
049    
050        @Override
051        public List<String> getOrderedFieldNames() {
052            return orderedFields;
053        }
054    
055        @SuppressWarnings({ "unchecked", "rawtypes" })
056        @Override
057        public Enum<?> newInstance() {
058            Enum<?> enumInstance = null;
059    
060            String enumValue = null;
061            try {
062                Class<? extends Enum> enumClass = (Class<? extends Enum>)ClassUtil.forName(type);
063                enumValue = (String)get("value");
064                if (enumValue == null) {
065                    Object[] enumConstants = enumClass.getEnumConstants();
066                    if (enumConstants == null || enumConstants.length == 0)
067                        throw new ServiceException("Invalid Enum type: " + type);
068                    enumValue = ((Enum<?>)enumConstants[0]).name();
069                }
070                enumInstance = Enum.valueOf(enumClass, enumValue);
071            } catch (ClassNotFoundException e) {
072                throw new ServiceException("Could not find Enum type for: " + type, e);
073            } catch (IllegalArgumentException e) {
074                throw new ServiceException("Could not find Enum constant for: " + type + '.' + enumValue, e);
075            }
076    
077            return enumInstance;
078        }
079    }