numberformatparser.java

swing编写的库存管理程序。毕业设计类

/**
 * ========================================
 * JFreeReport : a free Java report library
 * ========================================
 *
 * Project Info:  http://www.jfree.org/jfreereport/index.html
 * Project Lead:  Thomas Morgner;
 *
 * (C) Copyright 2000-2002, by Simba Management Limited and Contributors.
 *
 * This library 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 library 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
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * -----------------------
 * NumberFormatParser.java
 * -----------------------
 * (C)opyright 2000-2002, by Simba Management Limited.
 *
 * $Id: NumberFormatParser.java,v 1.2 2003/08/24 15:13:22 taqua Exp $
 *
 * ChangeLog
 * ---------
 */
package org.jfree.report.filter;

import java.text.Format;
import java.text.NumberFormat;

/**
 * A filter that parses the numeric value from a data source string into a number representation.
 * <p>
 * This filter will parse the string obtained from the datasource into a java.lang.Number
 * objects using a java.text.NumericFormat.
 * <p>
 * If the object read from the datasource is no number, the NullValue defined by
 * setNullValue(Object) is returned.
 *
 * @see java.text.NumberFormat
 *
 * @author Thomas Morgner
 */
public class NumberFormatParser extends FormatParser
{
  /**
   * Default constructor.
   * <P>
   * Uses a general number format for the current locale.
   */
  public NumberFormatParser()
  {
    setNumberFormat(NumberFormat.getInstance());
  }

  /**
   * Sets the number format.
   *
   * @param nf The number format.
   */
  public void setNumberFormat(final NumberFormat nf)
  {
    super.setFormatter(nf);
  }

  /**
   * Returns the number format.
   *
   * @return The number format.
   */
  public NumberFormat getNumberFormat()
  {
    return (NumberFormat) getFormatter();
  }

  /**
   * Sets the formatter.
   *
   * @param f The format.
   */
  public void setFormatter(final Format f)
  {
    final NumberFormat fm = (NumberFormat) f;
    super.setFormatter(fm);
  }

  /**
   * Turns grouping on or off for the current number format.
   *
   * @param newValue The new value of the grouping flag.
   */
  public void setGroupingUsed(final boolean newValue)
  {
    getNumberFormat().setGroupingUsed(newValue);
  }

  /**
   * Returns the value of the grouping flag for the current number format.
   *
   * @return The grouping flag.
   */
  public boolean isGroupingUsed()
  {
    return getNumberFormat().isGroupingUsed();
  }

  /**
   * Sets the maximum number of fraction digits for the current number format.
   *
   * @param newValue The number of digits.
   */
  public void setMaximumFractionDigits(final int newValue)
  {
    getNumberFormat().setMaximumFractionDigits(newValue);
  }

  /**
   * Returns the maximum number of fraction digits.
   *
   * @return The digits.
   */
  public int getMaximumFractionDigits()
  {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Sets the maximum number of digits in the integer part of the current number format.
   *
   * @param newValue The number of digits.
   */
  public void setMaximumIntegerDigits(final int newValue)
  {
    getNumberFormat().setMaximumFractionDigits(newValue);
  }

  /**
   * Returns the maximum number of integer digits.
   *
   * @return The digits.
   */
  public int getMaximumIntegerDigits()
  {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Sets the minimum number of fraction digits for the current number format.
   *
   * @param newValue The number of digits.
   */
  public void setMinimumFractionDigits(final int newValue)
  {
    getNumberFormat().setMaximumFractionDigits(newValue);
  }

  /**
   * Returns the minimum number of fraction digits.
   *
   * @return The digits.
   */
  public int getMinimumFractionDigits()
  {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Sets the minimum number of digits in the integer part of the current number format.
   *
   * @param newValue The number of digits.
   */
  public void setMinimumIntegerDigits(final int newValue)
  {
    getNumberFormat().setMaximumFractionDigits(newValue);
  }

  /**
   * Returns the minimum number of integer digits.
   *
   * @return The digits.
   */
  public int getMinimumIntegerDigits()
  {
    return getNumberFormat().getMaximumFractionDigits();
  }

  /**
   * Checks whether the given value is already a valid result. IF the datasource already returned
   * a valid value, and no parsing is required, a parser can skip the parsing process by returning
   * true in this function.
   *
   * @param o  the value to parse.
   *
   * @return true, if the given object is already an instance of number.
   */
  protected boolean isValidOutput(final Object o)
  {
    return o instanceof Number;
  }
}