You can choose the correct class depending on your pattern. The DateTimeFormatter class is used to format and parse the date in Java 8 and LocalDateTime represents a date with time in the local timezone. The steps are exactly the same but instead of using SimpleDateFormat and Date class, we'll use the DateTimeFormatter and LocalDateTime class. You can use the DateTimeFormatter class in JDK 8 to change the date format of String in Java 8. How to change the format of Date in Java String using JDK 8 If you are interested to learn more about this API and other interesting Java 8 features I suggest you pick an up-to-date course like The Complete Java MasterClass, which is recently updated to cover the latest Java version. This means, unlike SimpleDateFormat class, DateTimeFormatter is both thread-safe and immutable, as well easier to use which so many predefined formats. The old API was non-intuitive, not thread-safe, and mutable but the new API has corrected all that mistake. The new Date and Time API has built upon lessons learned from the previous failed attempt at creating a good date, time, and calendar API. In this article, I'll give you an example of both before and after JDK 8 so that you can change the date format of String in Java 8 or before, but before that let's see what's the difference between SimpleDateFormat and DateTimeFormatter class. If you already know how to convert a date to String then it's pretty easy for you but if you don't know when you need to learn about DateFormat classes like SimpleDateFormat in JDK 6 or 7 and the from the new Date and Time API in JDK 8. The same process is repeated in both Java 8 and before, only corresponding API and class changes. In the first step, you need to parse String to create an equivalent date using the current format, and then once you got the date, you need to again convert it back to String using the new format. How will you do that? Well, it's not that difficult. For example, you have something like " 20:10:00" and you want to convert it that date into "", or you want to convert from dd-MM-YY to MM-dd-YY or to any other format of your choice and need, but a valid date format as per Java specification. In the second example, we used the slash / between date parts to correctly convert from a string to the date data type.One of the common programming tasks in Java is to change the date format of a given Date or String. In Example 2, the string '7' was converted to the date ''. In Example 1, the string date as ‘ 20020304’ was converted to the date '' (a date data type. You can find a list of all specifiers in the PostgreSQL documentation. Next, ‘MM’ represents a 2-digit month and ‘DD’ a 2-digit day. The specifier ‘YYYY’ as the first four characters indicates that these represent a 4-digit year. The input format decides how PostgreSQL will process the characters in the string where the date is stored. Notice that the input format is a string. In our example, we used 'YYYYMMDD' and 'YYYY/MM/DD'. In our example, we used the strings '20020304' and '7'. This can be a string (a text value) or a text column containing date information. Use the function TO_DATE() to convert a text value containing a date to the date data type. SELECT TO_DATE('7', 'YYYY/MM/DD') AS new_date Notice the slightly different date format: Let’s look at Example 2 of the TO_DATE() function. SELECT TO_DATE('20020304', 'YYYYMMDD') AS new_date Īnd here’s the result of the query: new_date Here’s Example 1 of how to use the TO_DATE() function. Let’s convert a date string to the date data type instead of its current text data type. You’d like to convert a string containing a date to the PostgreSQL date data type.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |