PropertiesConverter.java

package org.nnsoft.guice.rocoto.converters;

/*
 *    Copyright 2009-2012 The 99 Software Foundation
 *
 *    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.
 */

import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.util.Properties;

import com.google.inject.ProvisionException;
import com.google.inject.TypeLiteral;

/**
 * Converter implementation for {@code java.util.Properties}.
 */
public final class PropertiesConverter
    extends AbstractConverter<Properties>
{

    /**
     * Default properties encoding {@code ISO-8859-1}.
     *
     * Properties.load(stream) expects it.
     */
    private static final String PROPERTIES_ENCODING = "ISO-8859-1";

    /**
     * {@inheritDoc}
     */
    public Object convert( String value, TypeLiteral<?> toType )
    {
        Properties properties = new Properties();
        ByteArrayInputStream bais = null;

        try
        {
            bais = new ByteArrayInputStream( value.getBytes( PROPERTIES_ENCODING ) );
            properties.load( bais );
        }
        catch ( IOException e )
        {
            // Should never happen.
            throw new ProvisionException( "Failed to parse " + value + "' into Properties", e );
        }
        finally
        {
            if ( bais != null )
            {
                try
                {
                    bais.close();
                }
                catch ( IOException e )
                {
                    // close quietly
                }
            }
        }

        return properties;
    }

}