- Java Introduction
- Java Getting Started
- Java Syntax
- Java Comments
- Java Variables
- Java Data Types
- Java Type Casting
- Java Operators
- Java Strings
- Java Math
- Java Booleans
- Java If ... Else
- Java Switch
- Java While Loop
- Java For Loop
- Java Break And Continue
- Java Arrays
- Java Methods
- Java Method Parameters
- Java Method Overloading
- Java Scope
- Java Recursion
- Java OOP
- Java Classes And Objects
- Java Class Attributes
- Java Class Methods
- Java Constructors
- Java Modifiers
- Java Encapsulation
- Java Packages
- Java Inheritance
- Java Polymorphism
- Java Inner Classes
- Java Abstraction
- Java Interface
- Java Enums
- Java User Input (Scanner)
- Java Date And Time
- Java ArrayList
- Java LinkedList
- Java HashMap
- Java HashSet
- Java Iterator
- Java Wrapper Classes
- Java Exceptions - Try...Catch
- Java Regular Expressions
- Java Threads
- Java Lambda Expressions
- Java Files
- Java Create And Write To Files
- Java Read Files
- Java Delete Files
Java Date and Time
Java Dates
Java does not have a built-in Date class, but we can import the java.time
package to work with the date and time API. The package includes many date and time classes. For example:
Class | Description |
---|---|
LocalDate |
Represents a date (year, month, day (yyyy-MM-dd)) |
LocalTime |
Represents a time (hour, minute, second and nanoseconds (HH-mm-ss-ns)) |
LocalDateTime |
Represents both a date and a time (yyyy-MM-dd-HH-mm-ss-ns) |
DateTimeFormatter |
Formatter for displaying and parsing date-time objects |
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Display Current Date
To display the current date, import the java.time.LocalDate
class, and use its now()
method:
Example
import java.time.LocalDate; // import the LocalDate class
public class Main {
public static void main(String[] args) {
LocalDate myObj = LocalDate.now(); // Create a date object
System.out.println(myObj); // Display the current date
}
}
The output will be:
2021-07-06
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Display Current Time
To display the current time (hour, minute, second, and nanoseconds), import the java.time.LocalTime
class, and use its now()
method:
Example
import java.time.LocalTime; // import the LocalTime class
public class Main {
public static void main(String[] args) {
LocalTime myObj = LocalTime.now();
System.out.println(myObj);
}
}
The output will be:
16:38:36.430461
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Display Current Date And Time
To display the current date and time, import the java.time.LocalDateTime
class, and use its now()
method:
Example
import java.time.LocalDateTime; // import the LocalDateTime class
public class Main {
public static void main(String[] args) {
LocalDateTime myObj = LocalDateTime.now();
System.out.println(myObj);
}
}
The output will be:
2021-07-06T16:38:36.468515
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Formatting Date And Time
The "T" in the example above is used to separate the date from the time. You can use the DateTimeFormatter
class with the ofPattern()
method in the same package to format or parse date-time objects. The following example will remove both the "T" and nanoseconds from the date-time:
Example
import java.time.LocalDateTime; // Import the LocalDateTime class
import java.time.format.DateTimeFormatter; // Import the DateTimeFormatter class
public class Main {
public static void main(String[] args) {
LocalDateTime myDateObj = LocalDateTime.now();
System.out.println("Before formatting: " + myDateObj);
DateTimeFormatter myFormatObj = DateTimeFormatter.ofPattern("dd-MM-yyyy HH:mm:ss");
String formattedDate = myDateObj.format(myFormatObj);
System.out.println("After formatting: " + formattedDate);
}
}
The output will be:
Before Formatting: 2021-07-06T16:38:36.469691
After Formatting: 06-07-2021 16:38:36
The ofPattern()
method accepts all sorts of values, if you want to display the date and time in a different format. For example:
Value | Example | |
---|---|---|
yyyy-MM-dd | "1988-09-29" | |
dd/MM/yyyy | "29/09/1988" | |
dd-MMM-yyyy | "29-Sep-1988" | |
E, MMM dd yyyy | "Thu, Sep 29 1988" |
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