DoubleConsumer is a functional interface that accepts a double argument and returns no result. The interface contains two methods:
acceptandThenThe DoubleConsumer interface is defined in the java.util.function package. To import the DoubleConsumer interface, we use the following import statement:
import java.util.function.DoubleConsumer;
acceptThis method accepts a single double input and performs the given operation on the input without returning any result.
void accept(double value)
double value - The input argument.The method doesn’t return any result.
Let’s see an example:
import java.util.function.*;public class Main{public static void main(String[] args) {// Implementation of DoubleConsumer interface that consumes and prints the passed valueDoubleConsumer doubleConsumer = (t) -> System.out.println("The passed parameter is - " + t);double parameter = 1002.32;// calling the accept method to execute the print operationdoubleConsumer.accept(parameter);}}
In the code above, we created an implementation of the DoubleConsumer interface that prints the passed double argument to the console.
andThenThis method is used to chain multiple DoubleConsumer implementations one after another. The method returns a composed DoubleConsumer of different implementations defined in order. If the evaluation of any DoubleConsumer implementation along the chain throws an exception, it is relayed to the caller of the composed function.
default DoubleConsumer andThen(DoubleConsumer after)
DoubleConsumer after - The next implementation of the DoubleConsumer to evaluate.The method returns a composed DoubleConsumer that performs the operation in a sequence defined.
Let’s see an example:
import java.util.function.DoubleConsumer;public class Main{public static void main(String[] args) {DoubleConsumer doubleConsumerProduct = i -> System.out.println("Product Consumer: " + (i * 10));DoubleConsumer doubleConsumerSum = i -> System.out.println("Sum Consumer: " + (i + 10));double parameter = 94.32;// Using andThen() methodDoubleConsumer doubleConsumerComposite = doubleConsumerSum.andThen(doubleConsumerProduct);doubleConsumerComposite.accept(parameter);}}
In the code above , we define the following implementations of the DoubleConsumer interface:
doubleConsumerProduct - This implementation prints the result of the passed double value multiplied by 10.doubleConsumerSum - This implementation prints the result of the sum of the passed double value and 10.In line 12, both the implementations are chained using the andThen method.