Answers for "java how to check if value is null"

java checking for null

Objects.isNull(obj) //returns true if the object is null

Objects.nonNull(obj) //returns true if object is not-null

if(Objects.nonNull(foo) && foo.something()) // Uses short-circuit as well. No Null-pointer Exceptions are thrown.

java check if int is null

An int is not null, it may be 0 if not initialized.

If you want an integer to be able to be null, you need to use Integer instead of int.

Integer id;
String name;

public Integer getId() { return id; }
Besides the statement if(person.equals(null)) can't be true, because if person is null, then a NullPointerException will be thrown. So the correct expression is if (person == null)