com.talvish.tales.parts.translators.PeriodToStringTranslator.java Source code

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Here is the source code for com.talvish.tales.parts.translators.PeriodToStringTranslator.java

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// ***************************************************************************
// *  Copyright 2011 Joseph Molnar
// *
// *  Licensed 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 com.talvish.tales.parts.translators;

import org.joda.time.Period;
import org.joda.time.format.PeriodFormatter;

/**
 * Translator that converts a Period into a string.
 * @author jmolnar
 *
 */
public class PeriodToStringTranslator extends NullTranslatorBase implements Translator {
    private final PeriodFormatter formatter;

    /**
     * Constructor that instructs a null object to be set to null string with no explicit formatter.
     */
    public PeriodToStringTranslator() {
        this(null, null);
    }

    /**
     * Constructor that takes the string value to return when a null object is received 
     * as well as an optional formatter. 
     * @param theNullValue the null value to use
     * @param theFormatter the optional formatter to use to create the string
     */
    public PeriodToStringTranslator(String theNullValue, PeriodFormatter theFormatter) {
        super(theNullValue);
        formatter = theFormatter;
    }

    /**
     * Translates the received object into a string.
     * If the object to translate isn't null but is of the wrong 
     * type, a TranslationException will occur.
     */
    @Override
    public Object translate(Object anObject) {
        Object returnValue;

        if (anObject == null) {
            returnValue = this.nullValue;
        } else {
            try {
                Period value = (Period) anObject;

                if (formatter == null) {
                    returnValue = value.toString();
                } else {
                    returnValue = value.toString(formatter);
                }
            } catch (ClassCastException e) {
                throw new TranslationException(e);
            }
        }
        return returnValue;
    }
}