为什么 Java 的 Date.getYear() 返回 111 而不是 2011?

2022-01-11 00:00:00 date calendar java

我在将字符串日期解析为 Date 对象时遇到了一些麻烦.我使用 DateFormat 来解析字符串，当我打印日期的值时，它给出了我所期望的.

I am having a bit of trouble parsing a string date to a Date object. I use a DateFormat to parse the string, and when I print the value of the date, it gives me what I expect.

但是当我尝试获取日期、月份或年份时，它给了我错误的值.例如，年份是 2011 年，但是当我执行 .getYear() 时，它给了我 111.我不知道为什么会这样.以下是相关代码段:

But when I try get the day, the month or the year it gives me the wrong values. For instance, the year is 2011, but when I do .getYear() it gives me 111. I have no idea why this is happening. Here is the relevant code segment:

    Date dateFrom = null;

    String gDFString = g.getDateFrom();

    System.out.println(gDFString);

    DateFormat df = new SimpleDateFormat("dd/MM/yyyy");

    try {
        dateFrom = df.parse("04/12/2011");

        System.out.println(dateFrom);

        System.out.println(dateFrom.getYear());
    } catch (ParseException e) {
        e.printStackTrace();
    }

当我输出 dateFrom 时，我得到 Sun Dec 04 00:00:00 GMT 2011，这是您所期望的.但是打印 .getYear() 会返回 111.

When I out print dateFrom, I get Sun Dec 04 00:00:00 GMT 2011, which is what you would expect. But printing .getYear() returns 111.

我需要能够为时间序列图获取日期的日、月和年.

I need to be able to get the day, month and year of the date for a time series graph.

推荐答案

这些方法已弃用.相反，请使用 Calendar 类.

Those methods have been deprecated. Instead, use the Calendar class. 

import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;

public final class DateParseDemo {
    public static void main(String[] args){
         final DateFormat df = new SimpleDateFormat("MM/dd/yyyy");
         final Calendar c = Calendar.getInstance();
         try {
             c.setTime(df.parse("04/12/2011"));
             System.out.println("Year = " + c.get(Calendar.YEAR));
             System.out.println("Month = " + (c.get(Calendar.MONTH)));
             System.out.println("Day = " + c.get(Calendar.DAY_OF_MONTH));
         } 
         catch (ParseException e) {
             e.printStackTrace();
         }
    }
}

输出:

Year = 2011
Month = 3
Day = 12

<小时>

对于 month 字段，这是从 0 开始的.这意味着一月 = 0 和十二月 = 11.正如 javadoc 所述,

And as for the month field, this is 0-based. This means that January = 0 and December = 11. As stated by the javadoc,

get 和 set 的字段编号，表示月份.这是一个特定于日历的值.公历一年的第一个月而儒略历是JANUARY，即0；最后取决于一年中的月数.

Field number for get and set indicating the month. This is a calendar-specific value. The first month of the year in the Gregorian and Julian calendars is JANUARY which is 0; the last depends on the number of months in a year.

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