org.xwiki.properties.converter.AbstractConverter Maven / Gradle / Ivy
/*
* See the NOTICE file distributed with this work for additional
* information regarding copyright ownership.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* 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. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.xwiki.properties.converter;
import java.lang.reflect.Type;
import org.xwiki.component.util.ReflectionUtils;
/**
* Helper base class for a {@link Converter} component.
*
* Commonly a new component is supposed to implements {@link AbstractConverter#convertToString(Object)} and
* {@link AbstractConverter#convertToType(Class, Object)}.
*
* @param the type in which the provided value has to be converted
* @version $Id: 1ab948f1f76935985bc9d433afff884dfda7650b $
* @since 2.0M2
*/
public abstract class AbstractConverter implements Converter
{
@Override
public G convert(Type targetType, Object sourceValue)
{
Class sourceType = sourceValue == null ? null : sourceValue.getClass();
G result;
if (targetType.equals(String.class)) {
// Convert --> String
result = (G) ((Class) targetType).cast(convertToString((T) sourceValue));
} else if (targetType.equals(sourceType)) {
// No conversion necessary
result = (G) sourceValue;
} else {
// Convert --> Type
result = (G) convertToType(targetType, sourceValue);
}
return result;
}
/**
* Convert the input object into a String.
*
* N.B.This implementation simply uses the value's toString() method and should be overridden if
* a more sophisticated mechanism for conversion to a String is required.
*
* @param value The input value to be converted.
* @return the converted String value.
*/
protected String convertToString(T value)
{
return value.toString();
}
/**
* Convert the input object into an output object of the specified type.
*
* Typical implementations will provide a minimum of {@code String --> type} conversion.
*
* @param the type in which the provided value has o be converted
* @param targetType Data type to which this value should be converted.
* @param value The input value to be converted.
* @return The converted value.
* @since 3.0M1
*/
protected G convertToType(Type targetType, Object value)
{
Class clazz = ReflectionUtils.getTypeClass(targetType);
// Call #convertToType(Class type, Object value) for retro-compatibility
return convertToType(clazz, value);
}
/**
* Convert the input object into an output object of the specified type.
*
* Typical implementations will provide a minimum of {@code String --> type} conversion.
*
* @param the type in which the provided value has o be converted
* @param type Data type to which this value should be converted.
* @param value The input value to be converted.
* @return The converted value.
* @deprecated since 3.0M1 overwrite {@link #convertToType(Type, Object)} instead
*/
@Deprecated
protected G convertToType(Class type, Object value)
{
return convertToType((Type) type, value);
}
}