我需要一个代码，该代码应使用Java从Excel获取YYYY-MM-DD格式的日期

Question

I need a code which should get Date from Excel as YYYY-MM-DD .

It is displaying the date as 31-Dec-2050 which was originally saved in sheet as 2050-12-31 Format.

System.out.println("<" + sheet.getRow(i).getCell(24) + ">");

should get Date from Excel as YYYY-MM-DD .

Answer 1

tl;dr

LocalDate.parse( 
    "31-Dec-2050" , 
    DateTimeFormatter.ofPattern( "dd-MMM-uuuu" , Locale.US )
)
.toString()

java.time

Your Question is unclear as you do not explain what library you might be using to read Excel files, nor do you explain what sheet.getRow(i).getCell(24) is doing. So I can only address how to parse a date string, and not give a potentially better, deeper answer.

If you are given the string 31-Dec-2050 you can parse that as a LocalDate in Java. The LocalDate class represents a date-only value without time-of-day and without time zone or offset-from-UTC .

Define a formatting pattern to match your textual input.

Pass a Locale to determine:

• The human language for translation of name of day, name of month, and such.
• The cultural norms deciding issues of abbreviation, capitalization, punctuation, separators, and such.

Ex:

String input = "31-Dec-2050" ;
DateTimeFormatter f = DateTimeFormatter.ofPattern( "dd-MMM-uuuu" , Locale.US ) ;
LocalDate ld = LocalDate.parse( input , f ) ;

See this code run live at IdeOne.com .

ld.toString(): 2050-12-31

Answer 2

Import:

import java.time.LocalDate;
import java.time.format.DateTimeFormatter;

Then in your class:

String cv = sheet.getRow(i).getCell(24).getStringCellValue();
DateTimeFormatter dt = DateTimeFormatter.ofPattern( "uuuu-MM-dd");
System.out.println("<" + LocalDate.parse(cv).format(dt) + ">");