Supplier Interface in Java with Examples

The Supplier Interface is a part of the java.util.function package which has been introduced since Java 8, to implement functional programming in Java. It represents a function which does not take in any argument but produces a value of type T.

Hence this functional interface takes in only one generic namely:-

• T: denotes the type of the result

The lambda expression assigned to an object of Supplier type is used to define its get() which eventually produces a value. Suppliers are useful when we don’t need to supply any value and obtain a result at the same time.

The Supplier interface consists of only one function:

1. get()

This method does not take in any argument but produces a value of type T.

Syntax:

T get()

Returns: This method returns a value of type T.

Below is the code to illustrate get() method:

Program:

import java.util.function.Supplier;

public class Main {
    public static void main(String args[])
    {

        // This function returns a random value.
        Supplier<Double> randomValue = () -> Math.random();

        // Print the random value using get()
        System.out.println(randomValue.get());
    }
}

Output:

0.5685808855697841