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Topic: 问一个Date类的奇怪问题

1.问一个Date类的奇怪问题

Posted by: hahaer1234
Posted on: 2005-04-13 15:24

小弟java初学，今天碰到一个不解的问题，向各位大虾请教，请不吝赐教
我在用Date类的时候，遇到这样一种现象，当我使用GetDay()方法的时候，如果调用方法的对象是系统默认时间的对象，得出来的星期几结果是正确的，如果是我指定时间定义的对象调用，则得出的星期几的结果不正确，请问这是怎么回事？是我的语法写的不对，还是和系统的配置或者OS有关呢？
谢谢

所写代码如下：

import java.util.*;

public class DayTest
{
  public static void main(String[] args)
  {
    Date date1=new Date();
    Date date2=new Date(2005,4,13);
    int week1=date1.getDay();
    int week2=date2.getDay();
    System.out.println("The Time1 is:"+(date1.getYear()+1900)+(date1.getMonth()+1)+date1.getDate()+
      " The Week1 is:"+week1);
    System.out.println("The Time2 is:"+date2.getYear()+date2.getMonth()+date2.getDate()+
      " The Week2 is:"+week2);
  }
}

结果如下：
The Time1 is 2005413 The Week1 is:3
The Time2 is 2005413 The Week2 is:6

2.Re:问一个Date类的奇怪问题 [Re: hahaer1234]	Copy to clipboard
Posted by: cxp108 Posted on: 2005-04-13 18:15 不要使用Date(int,int,int)这个构造函数，而使用Date(long)这个构造函数，如果算日期的话，一定要用setTime(long time) time 参数可以从当前日期加或减获得

3.Re:问一个Date类的奇怪问题 [Re: hahaer1234]

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Posted by: why
Posted on: 2005-04-13 20:37

是你的语法写的不对

new Date(2005,4,13); actually refers to (2005+1900)-(4+1)-13, i.e. 3905-5-13
sigh Sad

http://java.sun.com/j2se/1.4.2/docs/api/java/util/Date.html#Date(int, int, int, int, int)

Date
public Date(int year,
int month,
int date)
Deprecated. As of JDK version 1.1, replaced by Calendar.set(year + 1900, month, date) or GregorianCalendar(year + 1900, month, date).

Allocates a Date object and initializes it so that it represents midnight, local time, at the beginning of the day specified by the year, month, and date arguments.

Parameters:
year - the year minus 1900.
month - the month between 0-11.
date - the day of the month between 1-31.

4.Re:问一个Date类的奇怪问题 [Re: hahaer1234]	Copy to clipboard
Posted by: hahaer1234 Posted on: 2005-04-14 07:58 谢谢两位大佬,小弟明白啦