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.DecimalFormat;

import java.text.NumberFormat;

import java.text.ParsePosition;

import java.util.Date;

import org.gvsig.tools.dataTypes.AbstractCoercion;

import org.gvsig.tools.dataTypes.Coercion;

import org.gvsig.tools.dataTypes.CoercionException;

import org.gvsig.tools.dataTypes.DataTypeUtils;

import org.gvsig.tools.dataTypes.CoercionContext;

import org.gvsig.tools.dataTypes.CoercionContextLocale;

@SuppressWarnings("UseSpecificCatch")

public class CoerceToDouble extends AbstractCoercion {

  @Override

  public Object coerce(Object value) throws CoercionException {

    if (value == null || value instanceof Double) {

      return value;

    }

    return coerce(value, DataTypeUtils.coerceContextDefaultDecimal());

  }

  @Override

  public Object coerce(Object value, CoercionContext context) throws CoercionException {

    if (value == null || value instanceof Double) {

      return value;

    }

    CoercionContextLocale theContext;

    if (context instanceof CoercionContextLocale) {

      theContext = (CoercionContextLocale) context;

    } else {

      theContext = DataTypeUtils.coerceContextDefaultLocale();

    }

    Double num;

    try {

      if (value instanceof Number) {

        num = ((Number) value).doubleValue();

      } else if (value instanceof Boolean) {

        num = ((boolean) value ? 1d : 0d);

      } else if (value instanceof Date) {

        num = (double) (((Date) value).getTime());

      } else {

        String s = value.toString();

        if (s == null) {

          return null;

        }

        s = s.trim().toLowerCase();

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

          return null;

        }

        if (s.startsWith("0x")) {

          num = (double) Long.parseLong(s.substring(2), 16);

        } else {

          if (s.startsWith("+")) {

            s = s.substring(1);

          }

          ParsePosition p = new ParsePosition(0);

          DecimalFormat nf = (DecimalFormat) NumberFormat.getInstance(theContext.locale());

          Number n = nf.parse(s, p);

          if (p.getErrorIndex() > 0 || p.getIndex() < s.length()) {

            throw new CoercionException("Can't coerce '" + s + "' to double with locale " + theContext.locale().getLanguage() + "(error index " + p.getErrorIndex() + ", index " + p.getIndex() + ").");

          }

          num = n.doubleValue();

        }

      }

      return num;

    } catch (CoercionException e) {

      throw e;

    } catch (Exception e) {

      throw new CoercionException("Can't coerce '" + value.toString() + "' to double with locale " + theContext.locale().getLanguage() + "'.", e);

    }

  }

  public static void main(String[] args) throws CoercionException {

    Coercion toDouble = new CoerceToDouble();

    Double x = (double) toDouble.coerce("10.5");

    System.out.println(x);

    x = (double) toDouble.coerce("123456789.5");

    System.out.println(x);

    x = (double) toDouble.coerce("123,456,789.5");

    System.out.println(x);

  }

}