Calendar类的---如何取得当月第一天是星期几,有点疑惑,请帮忙

Question

java.util.Calendar currentCal = java.util.Calendar.getInstance();
//将当前日期改为月的第一天   
currentCal.set(currentCal.DAY_OF_MONTH, 1);
//获得当月第一天的星期值
dayOfWeek = currentCal.get(currentCal.DAY_OF_WEEK);其中currentCal.set(Calendar.DAY_OF_MONTH, 1); //假设 currentCal是 2005-6-23，那么现在的结果就是2005-6-1日
currentCal.get(currentCal.DAY_OF_WEEK);//怎么会返回本月第一天是星期几的呢?哪为高手帮忙解释一下!!

Answer 1

currentCal.DAY_OF_WEEK是一个static final int型，他只表示一个礼拜有多少天而已。
呵呵

Answer 2

呵呵，用这个可以。
public class Test {    public static void main(String[] args) {
        java.util.Calendar currentCal = java.util.Calendar.getInstance();
        currentCal.set(currentCal.DAY_OF_MONTH, 1);
        java.util.Date date = currentCal.getTime();
        java.text.SimpleDateFormat format = new java.text.SimpleDateFormat("E");
        System.out.println(format.format(date));
    }}

Answer 3

currentCal.get(currentCal.DAY_OF_WEEK);
currentCal.DAY_OF_WEEK表示你要得到的表示类型（当天在周内的表示方式）然后通过调用currentCal.get获得你所需要的值，并没有什么奇怪的啊。

Answer 4

给你这段代码,
<%=c.get(Calendar.YEAR)%>-<%=c.get(Calendar.MONTH)+1%>-<%=c.get(Calendar.DATE)%>
                    <%
                switch  (c.get(Calendar.DAY_OF_WEEK)){
                      case 1:
                            out.println("星期天");
                            break;
                      case 2:
                            out.println("星期一");
                            break;
                      case 3:
                            out.println("星期二");
                            break;
                      case 4:
                            out.println("星期三");
                            break;
                      case 5:
                            out.println("星期四");
                            break;
                      case 6:
                            out.println("星期五");
                            break;
                      case 7:
                            out.println("星期六");
                            break;
                      default:
                            break;
                }
                %>

Answer 5

int getTheFirstWeekDayInAMonth(int year, int month) {
  String[] weekdays = {"日", "一", "二", "三", "四", "五", "六"};
  return "星期" + weekdays[new GregorianCalendar(year, month, 1).get(Calendar.DAY_OF_WEEK) - 1];
}

Answer 6

public static String getCurWeek(Calendar calendar, boolean toChinese) {        String strRet = "";
        int intWeek = 0;
      //  System.out.println("-------calendar.date----------" + calendar.DATE);
       // System.out.println("-------calendar.DayOfWeek-----" + calendar.DAY_OF_WEEK);
       // System.out.println("aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa");
        intWeek = calendar.get(calendar.DAY_OF_WEEK) - 1; //获取本周的第几天
        //外国是星期天为每周第一天，所以减一
       // System.out.println("-----------intWeek----------------" + intWeek);
        calendar = null; //回收
        if (!toChinese) {
            return (String.valueOf(intWeek));
        }        switch (intWeek) {
            case 1:
                strRet = "星期一";
                break;
            case 2:
                strRet = "星期二";
                break;
            case 3:
                strRet = "星期三";
                break;
            case 4:
                strRet = "星期四";
                break;
            case 5:
                strRet = "星期五";
                break;
            case 6:
                strRet = "星期六";
                break;
            case 0:
                strRet = "星期日";
                break;
            default:
                strRet = "不详";
                break;
        }
        return strRet;
    }

Answer 7

public class aboutDate {
  static String[] week = {
      "星期天", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"};
  static String[] month = {
      "一月", "二月", "三月", "四月", "五月", "六月", "七月", "八月", "九月", "十月", "十一月", "十二月"};
  public aboutDate() {
  }
  public static void printDate(String date) {    Calendar currentCal = Calendar.getInstance();
    try {
      currentCal.setTime(new Date(date) );
      String d = currentCal.get(Calendar.YEAR) + "年" +
          month[currentCal.get(Calendar.MONTH )] +
          currentCal.get(Calendar.DATE) + "号" +
          week[currentCal.get(Calendar.DAY_OF_WEEK )];
      System.out.println(d) ;
    }
    catch (Exception ex) { System.out.println(ex) ;}  }
  public static void main(String[] args) throws Exception {    aboutDate aboutDate1 = new aboutDate();
    printDate("2005/09/02");
   }
}
output:
  2005年九月2号星期六