What is LongConsumer functional interface in Java?
LongConsumer is a functional interface that accepts a long argument and returns no result. The interface contains two methods:
acceptandThen
The LongConsumer interface is defined in the java.util.function package. To import the LongConsumer interface, check out the following import statement.
import java.util.function.LongConsumer;
1. The accept method
The accept method accepts a single long input and performs the given operation on the input without returning any result.
Syntax
void accept(long value)
Parameters
long value: The input argument.
Return value
The method doesn’t return any result.
Code
import java.util.function.*;public class Main{public static void main(String[] args) {// Implementation of LongConsumer interface that consumes and prints the passed valueLongConsumer longConsumer = (t) -> System.out.println("The passed parameter is - " + t);long parameter = 100232;// calling the accept method to execute the print operationlongConsumer.accept(parameter);}}
In the code above, we create an implementation of the LongConsumer interface that prints the passed long argument to the console.
2. The andThen method
The andThen method is used to chain multiple LongConsumer implementations one after another. The method returns a composed LongConsumer of different implementations defined in the order. If the evaluation of any LongConsumer implementation along the chain throws an exception, it is relayed to the caller of the composed function.
Syntax
default LongConsumer andThen(LongConsumer after)
Parameters
LongConsumer after: The next implementation of theLongConsumerto evaluate.
Return value
The method returns a composed LongConsumer that performs in sequence the operation defined followed by the after operation.
Code
import java.util.function.LongConsumer;public class Main{public static void main(String[] args) {LongConsumer longConsumerProduct = i -> System.out.println("Product Consumer - " + (i * 10));LongConsumer longConsumerSum = i -> System.out.println("Sum Consumer - " + (i + 10));long parameter = 9432;// Using andThen() methodLongConsumer longConsumerComposite = longConsumerSum.andThen(longConsumerProduct);longConsumerComposite.accept(parameter);}}
In the code above, we define the following implementations of the LongConsumer interface.
longConsumerProduct: This implementation prints the result of the passedlongvalue multiplied by10.longConsumerSum: This implementation prints the result of the sum of the passedlongvalue and10.
In line 12, both the implementations are chained using the andThen method.
