使用java.util.Calendar類取得本週一

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

/**
 * Test
 * @author
 */
public class Test {

    /**
     * main
     * @param args
     */
    public static void main(String[] args) {
        getMonday1();
        getMonday2();
    }

    /** 在JDK5沒有問題，但在JDK1.4下setFirstDayOfWeek()方法有問題。 */
    public static void getMonday1() {

        Date date = new Date();
        System.out.println(date);

        Calendar calendar = new GregorianCalendar();

        // 取得本週一
        calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
        calendar.setFirstDayOfWeek(Calendar.MONDAY);
        calendar.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);
        System.out.println(calendar.getTime());

        // 取得本週日
        System.out.println(new Date(calendar.getTime().getTime()
                + (7 * 24 * 60 * 60 * 1000)));
    }

    /** 在JDK1.4下的解決辦法。 */
    public static void getMonday2() {

        Calendar calendar = new GregorianCalendar();
        // 取得本週一
        calendar.set(calendar.get(Calendar.YEAR), calendar.get(Calendar.MONTH),
                calendar.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
        int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - 2;
        dayOfWeek = (dayOfWeek == -1) ? 6 : dayOfWeek;
        calendar.add(Calendar.DAY_OF_MONTH, (-1) * dayOfWeek);
        System.out.println(calendar.getTime());

    }

}