Java Language The java.util.Objects Class

Basic use for object null check

For null check in method

Object nullableObject = methodReturnObject();
if (Objects.isNull(nullableObject)) {
    return;
}

For not null check in method

Object nullableObject = methodReturnObject();
if (Objects.nonNull(nullableObject)) {
    return;
}

Objects.nonNull() method reference use in stream api

In the old fashion way for collection null check

List<Object> someObjects = methodGetList();
for (Object obj : someObjects) {
    if (obj == null) {
        continue;
    }
    doSomething(obj);
}

With the Objects.nonNull method and Java8 Stream API, we can do the above in this way:

List<Object> someObjects = methodGetList();
someObjects.stream()
           .filter(Objects::nonNull)
           .forEach(this::doSomething);