org.apache.commons.validator.routines.BigDecimalValidator.java Source code

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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.validator.routines;

import java.math.BigDecimal;
import java.text.Format;
import java.text.NumberFormat;
import java.util.Locale;

/**
 * <p>
 * <b>BigDecimal Validation</b> and Conversion routines (<code>java.math.BigDecimal</code>).
 * </p>
 * 
 * <p>
 * This validator provides a number of methods for validating/converting a <code>String</code> value to a <code>BigDecimal</code>
 * using <code>java.text.NumberFormat</code> to parse either:
 * </p>
 * <ul>
 * <li>using the default format for the default <code>Locale</code></li>
 * <li>using a specified pattern with the default <code>Locale</code></li>
 * <li>using the default format for a specified <code>Locale</code></li>
 * <li>using a specified pattern with a specified <code>Locale</code></li>
 * </ul>
 * 
 * <p>
 * Use one of the <code>isValid()</code> methods to just validate or one of the <code>validate()</code> methods to validate and
 * receive a <i>converted</i> <code>BigDecimal</code> value.
 * </p>
 * 
 * <p>
 * Fraction/decimal values are automatically trimmed to the appropriate length.
 * </p>
 * 
 * <p>
 * Once a value has been sucessfully converted the following methods can be used to perform minimum, maximum and range checks:
 * </p>
 * <ul>
 * <li><code>minValue()</code> checks whether the value is greater than or equal to a specified minimum.</li>
 * <li><code>maxValue()</code> checks whether the value is less than or equal to a specified maximum.</li>
 * <li><code>isInRange()</code> checks whether the value is within a specified range of values.</li>
 * </ul>
 * 
 * <p>
 * So that the same mechanism used for parsing an <i>input</i> value for validation can be used to format <i>output</i>,
 * corresponding <code>format()</code> methods are also provided. That is you can format either:
 * </p>
 * <ul>
 * <li>using the default format for the default <code>Locale</code></li>
 * <li>using a specified pattern with the default <code>Locale</code></li>
 * <li>using the default format for a specified <code>Locale</code></li>
 * <li>using a specified pattern with a specified <code>Locale</code></li>
 * </ul>
 * 
 * @version $Revision: 493905 $ $Date: 2007-01-08 02:11:38 +0000 (Seg, 08 Jan 2007) $
 * @since Validator 1.3.0
 */
public class BigDecimalValidator extends AbstractNumberValidator {

    private static final BigDecimalValidator VALIDATOR = new BigDecimalValidator();

    /**
     * Return a singleton instance of this validator.
     * 
     * @return A singleton instance of the BigDecimalValidator.
     */
    public static BigDecimalValidator getInstance() {
        return VALIDATOR;
    }

    /**
     * Construct a <i>strict</i> instance.
     */
    public BigDecimalValidator() {
        this(true);
    }

    /**
     * <p>
     * Construct an instance with the specified strict setting.
     * </p>
     * 
     * @param strict <code>true</code> if strict <code>Format</code> parsing should be used.
     */
    public BigDecimalValidator(boolean strict) {
        this(strict, STANDARD_FORMAT, true);
    }

    /**
     * <p>
     * Construct an instance with the specified strict setting and format type.
     * </p>
     * 
     * <p>
     * The <code>formatType</code> specified what type of <code>NumberFormat</code> is created - valid types are:
     * </p>
     * <ul>
     * <li>AbstractNumberValidator.STANDARD_FORMAT -to create <i>standard</i> number formats (the default).</li>
     * <li>AbstractNumberValidator.CURRENCY_FORMAT -to create <i>currency</i> number formats.</li>
     * <li>AbstractNumberValidator.PERCENT_FORMAT -to create <i>percent</i> number formats (the default).</li>
     * </ul>
     * 
     * @param strict <code>true</code> if strict <code>Format</code> parsing should be used.
     * @param formatType The <code>NumberFormat</code> type to
     *            create for validation, default is STANDARD_FORMAT.
     * @param allowFractions <code>true</code> if fractions are
     *            allowed or <code>false</code> if integers only.
     */
    protected BigDecimalValidator(boolean strict, int formatType, boolean allowFractions) {
        super(strict, formatType, allowFractions);
    }

    /**
     * <p>
     * Validate/convert a <code>BigDecimal</code> using the default <code>Locale</code>.
     * 
     * @param value The value validation is being performed on.
     * @return The parsed <code>BigDecimal</code> if valid or <code>null</code> if invalid.
     */
    public BigDecimal validate(String value) {
        return (BigDecimal) parse(value, (String) null, (Locale) null);
    }

    /**
     * <p>
     * Validate/convert a <code>BigDecimal</code> using the specified <i>pattern</i>.
     * 
     * @param value The value validation is being performed on.
     * @param pattern The pattern used to validate the value against, or the
     *            default for the <code>Locale</code> if <code>null</code>.
     * @return The parsed <code>BigDecimal</code> if valid or <code>null</code> if invalid.
     */
    public BigDecimal validate(String value, String pattern) {
        return (BigDecimal) parse(value, pattern, (Locale) null);
    }

    /**
     * <p>
     * Validate/convert a <code>BigDecimal</code> using the specified <code>Locale</code>.
     * 
     * @param value The value validation is being performed on.
     * @param locale The locale to use for the number format, system default if null.
     * @return The parsed <code>BigDecimal</code> if valid or <code>null</code> if invalid.
     */
    public BigDecimal validate(String value, Locale locale) {
        return (BigDecimal) parse(value, (String) null, locale);
    }

    /**
     * <p>
     * Validate/convert a <code>BigDecimal</code> using the specified pattern and/ or <code>Locale</code>.
     * 
     * @param value The value validation is being performed on.
     * @param pattern The pattern used to validate the value against, or the
     *            default for the <code>Locale</code> if <code>null</code>.
     * @param locale The locale to use for the date format, system default if null.
     * @return The parsed <code>BigDecimal</code> if valid or <code>null</code> if invalid.
     */
    public BigDecimal validate(String value, String pattern, Locale locale) {
        return (BigDecimal) parse(value, pattern, locale);
    }

    /**
     * Check if the value is within a specified range.
     * 
     * @param value The <code>Number</code> value to check.
     * @param min The minimum value of the range.
     * @param max The maximum value of the range.
     * @return <code>true</code> if the value is within the
     *         specified range.
     */
    public boolean isInRange(BigDecimal value, double min, double max) {
        return (value.doubleValue() >= min && value.doubleValue() <= max);
    }

    /**
     * Check if the value is greater than or equal to a minimum.
     * 
     * @param value The value validation is being performed on.
     * @param min The minimum value.
     * @return <code>true</code> if the value is greater than
     *         or equal to the minimum.
     */
    public boolean minValue(BigDecimal value, double min) {
        return (value.doubleValue() >= min);
    }

    /**
     * Check if the value is less than or equal to a maximum.
     * 
     * @param value The value validation is being performed on.
     * @param max The maximum value.
     * @return <code>true</code> if the value is less than
     *         or equal to the maximum.
     */
    public boolean maxValue(BigDecimal value, double max) {
        return (value.doubleValue() <= max);
    }

    /**
     * Convert the parsed value to a <code>BigDecimal</code>.
     * 
     * @param value The parsed <code>Number</code> object created.
     * @param formatter The Format used to parse the value with.
     * @return The parsed <code>Number</code> converted to a <code>BigDecimal</code>.
     */
    @Override
    protected Object processParsedValue(Object value, Format formatter) {
        BigDecimal decimal = null;
        if (value instanceof Long) {
            decimal = BigDecimal.valueOf(((Long) value).longValue());
        } else {
            decimal = new BigDecimal(value.toString());
        }

        int scale = determineScale((NumberFormat) formatter);
        if (scale >= 0) {
            decimal = decimal.setScale(scale, BigDecimal.ROUND_DOWN);
        }

        return decimal;
    }
}