Java - Output current time, date in desired format

Let`s see how to output the current time and date in a desired format with SimpleDateFormat. SimpleDateFormat is a class that has been used to print dates since before Java8.

Java8 introduced a new class called DateTimeFormatter which has the same behavior as SimpleDateFormat.

Here, we will learn how to output date with SimpleDateFormat.

Print current date and time

You can create a SimpleDateFormat object with a pattern like "yyyy-MM-dd". If you pass a time object to format(), it creates a string with the input pattern and returns it.

String pattern = "yyyy-MM-dd";
SimpleDateFormat simpleDateFormat = new SimpleDateFormat(pattern);

String date = simpleDateFormat.format(new Date());
System.out.println(date);

result

2020-04-11

Print date and time as StringBuffer

In the example above, format() returned the result as a String object.

If you want to return a StringBuffer, you can pass a StringBuffer object as an argument to format() as follows.

StringBuffer stringBuffer = new StringBuffer();
Date now = new Date();

SimpleDateFormat simpleDateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ssZ");
simpleDateFormat.format(now, stringBuffer, new FieldPosition(0));
System.out.println(stringBuffer);

result

2020-04-11 22:40:37+0900

Output as a string in a specific Locale

When outputting dates, you can also output strings in your preferred language.

When creating a SimpleDateFormat object, you can pass a Locale object along with the pattern. If you run the following code, you can see that the date is printed in the language that matches the set Locale.

String pattern = "EEEEE dd MMMMM yyyy HH:mm:ss.SSSZ";
SimpleDateFormat simpleDateFormat =
        new SimpleDateFormat(pattern, new Locale("ko", "KR"));
SimpleDateFormat simpleDateFormat2 =
        new SimpleDateFormat(pattern, new Locale("en", "US"));

String date = simpleDateFormat.format(new Date());
System.out.println(date);

date = simpleDateFormat2.format(new Date());
System.out.println(date);

result

토요일 11 4월 2020 23:03:48.889+0900
Saturday 11 April 2020 23:03:48.889+0900

When creating a Locale, you need to input the language code and country code in order like Locale(language, country).

Parse the date string

Instead of creating a Date object as a string, you can also convert a string into a Date object.

If you create a SimpleDateFormat object and pass the same string as the pattern as a parse() argument, a Date object is returned.

String pattern = "yyyy-MM-dd";
SimpleDateFormat simpleDateFormat = new SimpleDateFormat(pattern);

Date date = simpleDateFormat.parse("2018-09-09");
System.out.println(date);

pattern information

The meanings of the alphabets used when creating patterns are as follows:

The following are examples of commonly used patterns.

Reference

• journaldev
• tutorials.jenkov.com