NumberDecoder.java

/*
 * Milyn - Copyright (C) 2006 - 2010
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License (version 2.1) as published by the Free Software
 *  Foundation.
 *
 *  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:
 *  http://www.gnu.org/licenses/lgpl.txt
 */

package org.milyn.javabean.decoders;

import org.milyn.cdr.SmooksConfigurationException;
import org.milyn.javabean.DataDecodeException;
import org.milyn.javabean.DataEncoder;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Properties;

/**
 * Abstract {@link Number} based DataDecoder.
 * 
 * @author <a href="mailto:tom.fennelly@gmail.com">tom.fennelly@gmail.com</a>
 */
public abstract class NumberDecoder extends LocaleAwareDecoder implements DataEncoder {

    /**
     * Format.
     */
    public static final String FORMAT = "format";
    /**
     * Type.
     */
    public static final String TYPE = "type";
    private NumberType type;

    public static enum NumberType {
        RAW,
        PERCENTAGE,
        CURRENCY
    }

    private NumberFormat numberFormat;

    public void setConfiguration(Properties config) throws SmooksConfigurationException {
        super.setConfiguration(config);
        String pattern = config.getProperty(FORMAT);
        String typeConfig = config.getProperty(TYPE);
        Locale locale = getLocale();

        if(locale == null && pattern == null) {
            // Don't create a formatter if neither locale or
            // pattern are configured...
            return;
        }

        if(locale == null) {
            locale = Locale.getDefault();
        }

        if(typeConfig == null) {
            type = NumberType.RAW;
        } else {
            try {
                type = NumberType.valueOf(typeConfig);
            } catch(Exception e) {
                throw new SmooksConfigurationException("Unsupported Number type specification '" + typeConfig + "'.  Must be one of '" + NumberType.values() + "'.");
            }
        }

        if(type == NumberType.PERCENTAGE || (pattern != null && pattern.indexOf('%') != -1)) {
            type = NumberType.PERCENTAGE;
            numberFormat = NumberFormat.getPercentInstance(locale);
        } else if(type == NumberType.CURRENCY) {
            numberFormat = NumberFormat.getCurrencyInstance(locale);
        } else {
            numberFormat = NumberFormat.getInstance(locale);
            numberFormat.setGroupingUsed(false);
            if(pattern != null && numberFormat instanceof DecimalFormat) {
                ((DecimalFormat) numberFormat).applyPattern(pattern);
            }
        }
    }

    /**
     * Get the {@link NumberFormat} instance, if one exists.
     * @return A clone of the {@link NumberFormat} instance, otherwise null.
     */
    public NumberFormat getNumberFormat() {
        if(numberFormat != null) {
            return (NumberFormat) numberFormat.clone();
        } else {
            return null;
        }
    }

    public NumberType getType() {
        return type;
    }

    public boolean isPercentage() {
        return type == NumberType.PERCENTAGE;
    }

    public String encode(Object object) throws DataDecodeException {
        if(numberFormat != null) {
            return getNumberFormat().format(object);
        } else {
            return object.toString();
        }
    }
}