com.greenpepper.converter.AbstractTypeConverter Maven / Gradle / Ivy
/*
* Copyright (c) 2006 Pyxis Technologies inc.
*
* This is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; 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 com.greenpepper.converter;
import com.greenpepper.util.StringUtil;
/**
* Abstract base class for TypeConverter implementations that takes
* care handling null or empty string values. Subclasses are garanteed to
* receive a non-null and non-empty string in their doConvert()
* implementations.
*
* @version $Revision: $ $Date: $
* @author oaouattara
*/
public abstract class AbstractTypeConverter
implements TypeConverter
{
/**
* {@inheritDoc}
*
* Template implementation of the convert() method. Takes care
* of handling null and empty string values. Once these basic operations
* are handled, will delegate to the doConvert() method of
* subclasses.
*/
public Object parse(String value, Class type)
{
if (StringUtil.isBlank(value))
{
return null;
}
return doConvert(value.trim(), type);
}
/**
* {@inheritDoc}
*
* Basic implementation of the toString() method. Takes care
* of handling null values otherwise call the doToString of the object.
*/
public String toString(Object value)
{
if (value == null) return "";
return doToString(value);
}
/**
* Subclass must implement this method to do the actual type conversion.
* Subclass implementations are garanteed to receive a non-null and
* non-empty string.
*
* @param value The string value to convert
* @return The converted value, or null
*/
protected abstract Object doConvert(String value);
/**
* Do the conversion of the given value into the given type.
*
* @param value The string value to convert
* @param type a {@link java.lang.Class} object.
* @return The converted value, or null
*/
protected Object doConvert(String value, Class type) {
return doConvert(value);
}
/**
* Subclass must implement this method to overide the default call to the toString
* method of the value.
* Subclass implementations are garanteed to receive a non-null object.
*
* @param value The string value to convert
* @return The converted value, or null
*/
protected String doToString(Object value)
{
return String.valueOf(value);
}
}