Application: gvSIG desktop » Library: org.gvsig.tools

/**

 * gvSIG. Desktop Geographic Information System.

 *

 * Copyright (C) 2007-2013 gvSIG Association.

 *

 * This program 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 program 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 Street, Fifth Floor, Boston,

 * MA  02110-1301, USA.

 *

 * For any additional information, do not hesitate to contact us

 * at info AT gvsig.com, or visit our website www.gvsig.com.

 */

package org.gvsig.tools.dataTypes.impl.coercion;

import java.text.DateFormat;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Locale;

import org.gvsig.tools.dataTypes.CoercionException;

import org.gvsig.tools.dataTypes.DataTypesManager.CoercionWithLocale;

/**

 * Abstract implementation for Date coercion classes. If the value is not a

 * {@link Date}, it will use the {@link Object#toString()} method to convert the

 * resulting {@link String} to a Date object.

 *

 * @author gvSIG Team

 * @version $Id$

 */

public abstract class AbstractCoerceToDate implements CoercionWithLocale {

    @Override

    public Object coerce(Object value) throws CoercionException {

        return coerce(value, Locale.getDefault());

    }

    @Override

    public Object coerce(Object value, Locale locale) throws CoercionException {

        return coerce(value, this.getFormatters(locale));

    }

    protected Object coerce(Object value, DateFormat[] formatters) throws CoercionException {

            if( value == null ) {

            return null;

            }

        if ( value instanceof Date ) {

            return value;

        }

        if (value instanceof Long) {

            return new Date((long)value);

        }

        String valueStr = value.toString();

        if( valueStr == null ) {

           return null;

        }

        valueStr = valueStr.trim();

        if( valueStr.length()==0 ) {

            return null;

        }

        if( valueStr.toLowerCase().equals("now") ) {

            return this.now();

        }

        for (DateFormat formatter : formatters) {

            try {

                Date d = formatter.parse(valueStr);

                if( d!=null ) {

                    return d;

                }

            } catch (ParseException e) {

//                throw new CoercionException(getErrorMessage(formatters, valueStr),e);

            }

        }

        throw new CoercionException(getErrorMessage(formatters, valueStr));

    }

    private String getErrorMessage(DateFormat[] formatters, String value) throws CoercionException {

        StringBuilder builder = new StringBuilder();

        builder.append("The value to coerce (\"");

        builder.append(value);

        builder.append("\") has an invalid ");

        builder.append(getDateType());

        builder.append(" String format. The expected one is:");

        for (DateFormat formatter : formatters) {

            String formatDesc = formatter instanceof SimpleDateFormat ? 

                ((SimpleDateFormat) formatter).toLocalizedPattern() : 

                formatter.toString();

            builder.append(" '");

            builder.append(formatDesc);

            builder.append("'");

        }

        return builder.toString();

    }

    /**

     * Returns the {@link DateFormat} to apply when the value to coerce is not

     * of Date type and it will be parsed as String.

     *

     * @param locale

     * @return the {@link DateFormat} to apply to parse the value to coerce as

     *         {@link String}

     */

    protected abstract DateFormat[] getFormatters(Locale locale);

    protected abstract Date now();

    /**

     * Returns the name of the Date type being coerced. Ex: Date, DateTime,

     * Time. Only used for description when an error is produced when coercing

     * the value.

     *

     * @return the name of the Date type being coerced

     */

    protected abstract String getDateType();

}