将Excel日期转换为mm / dd / yyyy格式

Question

I am reading from an excel sheet using poi jar where in there is a date column.If i print out the value of the data cloumn :

cell.getDateCellValue()

It gives me value like 3124.0

So i tried with this code to convert to the mm/dd/yyyy format:

SimpleDateFormat sdf = new SimpleDateFormat("MM/DD/YYYY");
String  s =  sdf.format(cell.getDateCellValue());
System.out.println(s);

But for reading a date 06/30/2001 i got this value as output:

06/181/2001

Answer 1

First check your date format

  SimpleDateFormat sdf = new SimpleDateFormat("MM/DD/YYYY");

it should be

 SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");

and also check the POI API For more info to deal with dates in excel,there are better ways to handle the dates.

Refer HSSFDateUtil

check HSSFDateUtil.isCellDateFormatted() , getExcelDate ,getJavaDate

getJavaDate

public static java.util.Date getJavaDate(double date)

Given an Excel date with using 1900 date windowing, and converts it to a java.util.Date.

NOTE: If the default TimeZone in Java uses Daylight Saving Time then the conversion back to an Excel date may not give the same value, that is the comparison excelDate == getExcelDate(getJavaDate(excelDate,false)) is not always true. For example if default timezone is Europe/Copenhagen, on 2004-03-28 the minute after 01:59 CET is 03:00 CEST, if the excel date represents a time between 02:00 and 03:00 then it is converted to past 03:00 summer time Parameters:

date - The Excel date. Returns: Java representation of the date, or null if date is not a valid Excel date

See Also: TimeZone

also refer Reading date values from excel cell using POI HSSF API

Answer 2

Your Date Format String is wrong. Should be like following

SimpleDateFormat sdf = new SimpleDateFormat("MM/dd/yyyy");

Read the Java doc for SimpleDateFormat

Answer 3

Check out the JavaDoc for java.text.SimpleDateFormat :

D is for Day in year

Y is for Week in year.

You propably want to use the lowercase variants for d Day in Month and y Year

Answer 4

You want to write "MM/dd/yyyy" as your date format. Capital DD means day of year, which for 30 June is 181.

I strongly recommend reading the JavaDoc for the SimpleDateFormat class .