XMLGregorianCalendar from GregorianCalendar

XMLGregorianCalendar from GregorianCalendar

import org.junit.Test;

import javax.xml.datatype.DatatypeConfigurationException;
import javax.xml.datatype.DatatypeFactory;
import javax.xml.datatype.XMLGregorianCalendar;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.GregorianCalendar;

import static junit.framework.Assert.assertEquals;

public class MessTest {

    @Test
    public void shouldTranslateValidCalendar() throws DatatypeConfigurationException {
        GregorianCalendar cal = new GregorianCalendar(2013, 1, 1, 1, 1, 1);
        XMLGregorianCalendar xmlCal = new Mess().translateToXMLCal(cal);
        verifyDateSameness(cal, xmlCal);
    }

    private void verifyDateSameness(GregorianCalendar cal, XMLGregorianCalendar xmlCal) {
        assertEquals(xmlCal.toString(), xmlCalFormatter(cal));
        assertEquals(xmlCal.getYear(), cal.get(Calendar.YEAR));
        assertEquals(xmlCal.getMonth(), cal.get(Calendar.MONTH) + 1); // GregorianCalendar starts at 0 and XMLGregorianCalendar starts at 1
        assertEquals(xmlCal.getDay(), cal.get(Calendar.DAY_OF_MONTH));
        assertEquals(xmlCal.getHour(), cal.get(Calendar.HOUR));
        assertEquals(xmlCal.getMinute(), cal.get(Calendar.MINUTE));
        assertEquals(xmlCal.getSecond(), cal.get(Calendar.SECOND));
        assertEquals(xmlCal.getMillisecond(), cal.get(Calendar.MILLISECOND));
        assertEquals(xmlCal.getTimezone(), cal.get(Calendar.ZONE_OFFSET) / 60000); // Not sure why zone offset requires this translation
    }

    private String xmlCalFormatter(GregorianCalendar cal) {
        SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSSZ");
        String timeWithoutColon = fmt.format(cal.getTime());
        int afterMilliseconds = 26;
        return timeWithoutColon.substring(0, afterMilliseconds) + ":" + timeWithoutColon.substring(afterMilliseconds, timeWithoutColon.length());
    }

    public class Mess {
        public XMLGregorianCalendar translateToXMLCal(GregorianCalendar cal) throws DatatypeConfigurationException {
            return DatatypeFactory.newInstance().newXMLGregorianCalendar(cal);
        }
    }
}