Java 使用 SimpleDateFormat 分别获取日、月和年

Get day, month and year separately using SimpleDateFormat

提问by John Error

I have a SimleDateFormatlike this

我有一个SimleDateFormat这样的

SimpleDateFormat format = new SimpleDateFormat("MMM dd,yyyy  hh:mm");
String date = format.format(Date.parse(payback.creationDate.date));

I'm giving date with the format like "Jan,23,2014".

我用类似的格式给出日期"Jan,23,2014"。

Now, I want to get day, month and year separately. How can I implement this?

现在，我想分别获得日、月和年。我该如何实施？

采纳答案by Duncan Jones

If you need to get the values separately, then use more than one SimpleDateFormat.

如果您需要分别获取这些值，请使用多个SimpleDateFormat.

SimpleDateFormat dayFormat = new SimpleDateFormat("dd");
String day = dayFormat.format(Date.parse(payback.creationDate.date));

SimpleDateFormat monthFormat = new SimpleDateFormat("MM");
String month = monthFormat .format(Date.parse(payback.creationDate.date));

etc.

等等。

回答by Mani

Are you accepting this ?

你接受这个吗？

int day = 25 ; //25
int month =12; //12
int year = 1988; // 1988
Calendar c = Calendar.getInstance();
c.set(year, month-1, day, 0, 0);    
SimpleDateFormat format =   new SimpleDateFormat("MMM dd,yyyy  hh:mm");
System.out.println(format.format(c.getTime()));

Display as Dec 25,1988 12:00

显示为 Dec 25,1988 12:00

UPDATE : based on Comment

更新：基于评论

DateFormat format =   new SimpleDateFormat("MMM");
System.out.println(format.format(format.parse("Jan,23,2014")));

NOTE: Date.parse() is @deprecated and as per API it is recommend to use DateFormat.parse

注意：Date.parse() 是@deprecated，根据 API 建议使用 DateFormat.parse

回答by John Ding

Use this to parse "Jan,23,2014"

使用它来解析“Jan,23,2014”

SimpleDateFormat fmt = new SimpleDateFormat("MMM','dd','yyyy"); 
Date dt = fmt.parse("Jan,23,2014");

then you can get whatever part of the date.

那么你可以得到日期的任何部分。

回答by nikis

Wow, SimpleDateFormatfor getting string parts? It can be solved much easier if your input string is like "Jan,23,2014":

哇，SimpleDateFormat为了获得弦乐零件？如果您的输入字符串类似于“Jan,23,2014”，则可以更轻松地解决该问题：

String input = "Jan,23,2014";
String[] out = input.split(",");
System.out.println("Year = " + out[2]);
System.out.println("Month = " + out[0]);
System.out.println("Day = " + out[1]);

Output:

输出：

Year = 2014
Month = Jan
Day = 23

But if you really want to use SimpleDateFormatbecause of some reason, the solution will be the following:

但是如果SimpleDateFormat因为某种原因真的要使用的话，解决办法如下：

String input = "Jan,23,2014";
SimpleDateFormat format = new SimpleDateFormat("MMM,dd,yyyy");
Date date = format.parse(input);
Calendar calendar = Calendar.getInstance(TimeZone.getDefault());
calendar.setTime(date);
System.out.println(calendar.get(Calendar.YEAR));
System.out.println(calendar.get(Calendar.DAY_OF_MONTH));
System.out.println(new SimpleDateFormat("MMM").format(calendar.getTime()));

Output:

输出：

2014
23
Jan

回答by Udo Klimaschewski

    SimpleDateFormat format = new SimpleDateFormat("MMM dd,yyyy  hh:mm", Locale.ENGLISH);

    Date theDate = format.parse("JAN 13,2014  09:15");

    Calendar myCal = new GregorianCalendar();
    myCal.setTime(theDate);

    System.out.println("Day: " + myCal.get(Calendar.DAY_OF_MONTH));
    System.out.println("Month: " + myCal.get(Calendar.MONTH) + 1);
    System.out.println("Year: " + myCal.get(Calendar.YEAR));

回答by Thanh Thinh

public static String getDate(long milliSeconds, String dateFormat) {
        // Create a DateFormatter object for displaying date in specified
        // format.
        SimpleDateFormat formatter = new SimpleDateFormat(dateFormat,
                Locale.getDefault());

        // Create a calendar object that will convert the date and time value in
        // milliseconds to date.
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(milliSeconds);
        return formatter.format(calendar.getTime());
    }

回答by Thanh Thinh

The accepted answer here suggests to use more than one SimpleDateFormat, but it's possible to do this using one SimpleDateFormatinstance and calling applyPattern.

此处接受的答案建议使用多个SimpleDateFormat，但可以使用一个SimpleDateFormat实例并调用applyPattern.

Note: I believe this post would also be helpful for those who were searching for setPattern() just like me.

注意：我相信这篇文章对那些和我一样正在搜索 setPattern() 的人也会有所帮助。

Date date=new Date();
SimpleDateFormat simpleDateFormat = new SimpleDateFormat();
simpleDateFormat.applyPattern("dd");
System.out.println("Day   : " + simpleDateFormat.format(date));
simpleDateFormat.applyPattern("MMM");
System.out.println("Month : " + simpleDateFormat.format(date));
simpleDateFormat.applyPattern("yyyy");
System.out.println("Year  : " + simpleDateFormat.format(date));

回答by Basil Bourque

tl;dr

tl;博士

Use LocalDateclass.

使用LocalDate类。

LocalDate
.parse(
    "Jan,23,2014" , 
    DateTimeFormatter.ofPattern( "MMM,dd,uuuu" , Locale.US )
)
.getYear()

… or .getMonthValue()or .getDayOfMonth.

... 或.getMonthValue()或.getDayOfMonth。

java.time

时间

The other Answers use outmoded classes. The java.time classes supplant those troublesome old legacy classes.

其他答案使用过时的类。java.time 类取代了那些麻烦的旧遗留类。

LocalDate

LocalDate

The LocalDateclass represents a date-only value without time-of-day and without time zone.

该LocalDate级表示没有时间一天和不同时区的日期，唯一的价值。

String input = "Jan,23,2014";
DateTimeFormatter f = DateTimeFormatter.ofPattern( "MMM,d,uuuu" );
LocalDate ld = LocalDate.parse( input , f );

Interrogate for the parts you want.

询问您想要的部分。

int year = ld.getYear();
int month = ld.getMonthValue();
int dayOfMonth = ld.getDayOfMonth();

---

---

About java.time

关于java.time

The java.timeframework is built into Java 8 and later. These classes supplant the troublesome old legacydate-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

该java.time框架是建立在Java 8和更高版本。这些类取代了麻烦的旧的遗留日期时间类，例如java.util.Date, Calendar, & SimpleDateFormat。

The Joda-Timeproject, now in maintenance mode, advises migration to the java.timeclasses.

现在处于维护模式的Joda-Time项目建议迁移到java.time类。

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

要了解更多信息，请参阅Oracle 教程。并在 Stack Overflow 上搜索许多示例和解释。规范是JSR 310。

You may exchange java.timeobjects directly with your database. Use a JDBC drivercompliant with JDBC 4.2or later. No need for strings, no need for java.sql.*classes.

您可以直接与您的数据库交换java.time对象。使用符合JDBC 4.2或更高版本的JDBC 驱动程序。不需要字符串，不需要类。java.sql.*

Where to obtain the java.time classes?

从哪里获得 java.time 类？

• Java SE 8, Java SE 9, Java SE 10, Java SE 11, and later - Part of the standard Java API with a bundled implementation.
  • Java 9 adds some minor features and fixes.
• Java SE 6and Java SE 7
  • Most of the java.time functionality is back-ported to Java 6 & 7 in ThreeTen-Backport.
• Android
  • Later versions of Android bundle implementations of the java.timeclasses.
  • For earlier Android (<26), the ThreeTenABPproject adapts ThreeTen-Backport(mentioned above). See How to use ThreeTenABP….

• Java SE 8、Java SE 9、Java SE 10、Java SE 11和更高版本 - 标准 Java API 的一部分，具有捆绑实现。
  • Java 9 添加了一些小功能和修复。
• Java SE 6和Java SE 7
  • 大部分 java.time 功能在ThreeTen-Backport 中向后移植到 Java 6 & 7 。
• 安卓
  • 更高版本的 Android 捆绑实现java.time类。
  • 对于早期的 Android（<26），ThreeTenABP项目采用了ThreeTen-Backport（上面提到过）。请参阅如何使用ThreeTenABP ...。

The ThreeTen-Extraproject extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

该ThreeTen-额外项目与其他类扩展java.time。该项目是未来可能添加到 java.time 的试验场。你可能在这里找到一些有用的类，比如Interval，YearWeek，YearQuarter，和更多。