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.math.BigDecimal;

import java.text.DecimalFormat;

import java.text.NumberFormat;

import java.text.ParsePosition;

import java.util.Date;

import java.util.Locale;

import org.apache.commons.lang3.StringUtils;

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;

import org.gvsig.tools.dataTypes.CoercionContextDecimal;

import org.gvsig.tools.dataTypes.CoercionContextDecimalImpl;

@SuppressWarnings("UseSpecificCatch")

public class CoerceToDecimal extends AbstractCoercion {

  @Override

  public Object coerce(Object value) throws CoercionException {

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

      return value;

    }

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

  }

  @Override

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

    if (value == null ) {

      return value;

    }

    CoercionContextDecimal theContext;

    if (context instanceof CoercionContextDecimal) {

      theContext = (CoercionContextDecimal) context;

    } else {

      if (context instanceof CoercionContextLocale) {

        theContext = DataTypeUtils.coerceContextDecimal(((CoercionContextLocale) context).locale());

      } else {

        theContext = DataTypeUtils.coerceContextDefaultDecimal();

      }

    }

    BigDecimal num;

    try {

      if (value instanceof BigDecimal) {

        num = (BigDecimal) value;

      } else if (value instanceof Number) {

        num = new BigDecimal(((Number) value).doubleValue(), theContext.getMathContext());

      } else if (value instanceof Boolean) {

        num = new BigDecimal((boolean) value ? 1 : 0, theContext.getMathContext());

      } else if (value instanceof Date) {

        num = new BigDecimal(((Date) value).getTime(), theContext.getMathContext());

      } else {

        String s = value.toString().trim().toLowerCase();

        if (StringUtils.isBlank(s)) {

          return null;

        }

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

          num = new BigDecimal(Long.parseLong(s.substring(2), 16), theContext.getMathContext());

        } else {

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

            s = s.substring(1);

          }

          ParsePosition p = new ParsePosition(0);

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

          nf.setParseBigDecimal(true);

          num = (BigDecimal) nf.parse(s, p);

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

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

          }

        }

      }

      if( theContext.hasScale() && num.scale()!=theContext.scale()) {

        // Ojo, que este set no es un set. Contruye un nuevo BigDecimal, no

        // modifica el existente.

        num = num.setScale(theContext.scale(), theContext.roundMode());

      }

      if( theContext.hasPrecision() && num.precision()>theContext.precision() ) {

        throw new ArithmeticException("Overflow");

      }

      return num;

    } catch (CoercionException e) {

      throw e;

    } catch (Exception e) {

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

    }

  }

  private static BigDecimal toBigDecimal(Object value, int precision, int scale) throws CoercionException {

      CoercionContextDecimalImpl context = new CoercionContextDecimalImpl(Locale.ENGLISH, precision, scale);

      Coercion c = new CoerceToDecimal();              

      BigDecimal x = (BigDecimal) c.coerce(value,context);

      return x;

  }

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

    BigDecimal n;

    n = toBigDecimal(1,6,3);

    System.out.println("BigDecimal(1,6,3): "+n+"("+n.precision()+","+n.scale()+")");

    n = toBigDecimal(10,6,3);

    System.out.println("BigDecimal(10,6,3): "+n+"("+n.precision()+","+n.scale()+")");

    n = toBigDecimal(12.345,6,3);

    System.out.println("BigDecimal(12.345,6,3): "+n+"("+n.precision()+","+n.scale()+")");

    n = toBigDecimal(-12.345,6,3);

    System.out.println("BigDecimal(-12.345,6,3): "+n+"("+n.precision()+","+n.scale()+")");

    n = toBigDecimal(12.3457,6,3);

    System.out.println("BigDecimal(12.3457,6,3): "+n+"("+n.precision()+","+n.scale()+")");

    n = toBigDecimal(120.3457,6,3);

    System.out.println("BigDecimal(120.3457,6,3): "+n+"("+n.precision()+","+n.scale()+")");

  }

}