Java 8 Stream API to find Unique Object matching a property value

Question

Find the object matching with a Property value from a Collection using Java 8 Stream.

List objects = new ArrayList<>();

Pe

Answer 1

Guava API provides MoreCollectors.onlyElement() which is a collector that takes a stream containing exactly one element and returns that element.

The returned collector throws an IllegalArgumentException if the stream consists of two or more elements, and a NoSuchElementException if the stream is empty.

Refer the below code for usage:

import static com.google.common.collect.MoreCollectors.onlyElement;

Person matchingPerson = objects.stream
                        .filter(p -> p.email().equals("testemail"))
                        .collect(onlyElement());