What are the different ways to check if an object is null in Java besides `== null`?

General Discussions
1

I need to create a method that checks whether a class instance is null or not. Normally, I would just use == null, but I’m curious if there are any other ways to perform this check in Java.

Here’s my situation:

  • I have 70-80 class instances, all of which extend the same base class BaseEntity.
  • These instances are initially declared as null and later initialized using new.
  • At the end of my Entity Processor, I need to save only the initialized entities to the database.

Currently, I’m using this method:

public boolean checkIfEntityNull(BaseEntity entity) {
    return entity != null ? true : false;
}

If this method returns true, I proceed to call the save() method of the repository. Otherwise, I skip it.

Is there any alternative way to check null in Java besides using == null?

2

Hey! It looks like you’re dealing with a lot of entity instances and need a reliable way to check whether they are null before saving them.

While using == null is the most common approach, using Objects.isNull() and Objects.nonNull().

Java provides the Objects utility class, which makes null checks cleaner and more readable.

import java.util.Objects;

public boolean checkIfEntityNull(BaseEntity entity) {
    return Objects.nonNull(entity);  // Returns true if not null
}
3

Another great way is using Optional to wrap your object and check if it’s present.

import java.util.Optional;

public boolean checkIfEntityNull(BaseEntity entity) {
    return Optional.ofNullable(entity).isPresent(); // Returns true if not null
}

It makes the code more null-safe and avoids NullPointerException when chaining methods.

4

This approach works if you want to check only for instances of a specific class.

Solution:

public boolean checkIfEntityNull(BaseEntity entity) {
    return entity instanceof BaseEntity;  // Returns false if null
}

If your entities must be instances of BaseEntity, this ensures they are both non-null and valid instances.