YesterdayDate.java

/**
 * AnalyzerBeans
 * Copyright (C) 2014 Neopost - Customer Information Management
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * 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 Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.eobjects.analyzer.util.convert;

import java.util.Calendar;
import java.util.Date;

/**
 * Special date value "YESTERDAY()", meaning the day before today, at midnight.
 */
public class YesterdayDate extends Date implements ExpressionDate {

    private static final long serialVersionUID = 1L;

    public YesterdayDate() {
        super(calculateMillis());
    }

    public static long calculateMillis() {
        Calendar cal = Calendar.getInstance();
        // set time to 00:00:00.000
        cal.set(Calendar.HOUR_OF_DAY, 0);
        cal.set(Calendar.MINUTE, 0);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);

        // subtract one day
        cal.add(Calendar.DATE, -1);
        return cal.getTimeInMillis();
    }

    @Override
    public String getExpression() {
        return "yesterday()";
    }
}