EnumConverter.java

/*
 * Copyright 2005 Joe Walker
 *
 * 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.directwebremoting.convert;

import java.lang.reflect.Method;

import org.directwebremoting.ConversionException;
import org.directwebremoting.extend.AbstractConverter;
import org.directwebremoting.extend.InboundVariable;
import org.directwebremoting.extend.NonNestedOutboundVariable;
import org.directwebremoting.extend.OutboundContext;
import org.directwebremoting.extend.OutboundVariable;
import org.directwebremoting.util.LocalUtil;

/**
 * Converter for Enums
 * @author Joe Walker [joe at getahead dot ltd dot uk]
 */
public class EnumConverter extends AbstractConverter
{
    /* (non-Javadoc)
     * @see org.directwebremoting.extend.Converter#convertInbound(java.lang.Class, org.directwebremoting.extend.InboundVariable, org.directwebremoting.extend.InboundContext)
     */
    public Object convertInbound(Class<?> paramType, InboundVariable data) throws ConversionException
    {
        if (data.isNull())
        {
            return null;
        }

        String value = LocalUtil.urlDecode(data.getValue());

        try
        {
            Method getter = paramType.getMethod("valueOf", String.class);
            Object reply = getter.invoke(paramType, value);
            if (reply == null)
            {
                throw new ConversionException(paramType);
            }
            return reply;
        }
        catch (NoSuchMethodException ex)
        {
            // We would like to have done: if (!paramType.isEnum())
            // But this catch block has the same effect
            throw new ConversionException(paramType);
        }
        catch (Exception ex)
        {
            throw new ConversionException(paramType, ex);
        }
    }

    /* (non-Javadoc)
     * @see org.directwebremoting.extend.Converter#convertOutbound(java.lang.Object, org.directwebremoting.extend.OutboundContext)
     */
    public OutboundVariable convertOutbound(Object data, OutboundContext outctx)
    {
        return new NonNestedOutboundVariable('\'' + ((Enum<?>) data).name() + '\'');
    }
}