Is there a Java standard "both null or equal" static method?

Question

To save some typing and clarify my code, is there a standard version of the following method?

public static boolean bothNullOrEqual(Object x, Object y) {
  return ( x == null ? y == null : x.equals(y) );
}

Just my two cents. I would use: public static boolean bothNullOrEqual(Object x, Object y) { return ( x == y || ( x != null && x.equals(y) ) ); } IMHO, It's more readable for novice programmers. — m_vitaly, Sep 05 '10 at 07:49
It just allows you to skip null checks in your equals() method. — Michael Myers, Oct 08 '08 at 21:47
Only if you only ever use the bothNullOrEqual function... what if you use equals directly in one place? — Neil Williams, Oct 08 '08 at 22:13
It does seem strange that you'd want the same behaviour if two objects were equal OR were both NULL ... — Bobby Jack, Oct 08 '08 at 22:16
If you are implementing a Collection, your .contains() method, when given "o" needs to test "if this collection contains at least one element e such that (o==null ? e==null : o.equals(e))." Similarly, your .remove() method has to remove such an element. — newacct, Jul 09 '09 at 06:16
Another use case: compare a value to see if it has changed from it's previous value during a dirty check. — Relefant, Nov 16 '13 at 23:48
You might want to update the selected answer to @Kdeveloper's Java 7 solution. — Marc M., May 03 '16 at 00:21

score 195 · Accepted Answer · edited Jun 20 '20 at 09:12

195

With Java 7 you can now directly do a null safe equals:

(The Jakarta Commons library ObjectUtils.equals() has become obsolete with Java 7)

edited Jun 20 '20 at 09:12

Community

answered Feb 20 '12 at 15:31

Kdeveloper

This method is also implemented in Googles Dependency injection-libray Guice. – Niels Jun 11 '12 at 12:30
1

Spring also implements a similar method: nullSafeEquals on ObjectUtils class – jpsstavares Jul 17 '12 at 16:32
2

Google Guava has Objects.equals() as well. – Spina Apr 11 '13 at 18:27
1

This is only nullsafe concering x. For y it depends on the implementation of equals of the given object. (the implementation is `return (x == y) || (x != null && x.equals(y));`) – emi-le Apr 06 '18 at 09:09

score 23 · Answer 2 · edited Dec 18 '12 at 13:06

23

if by some chance you are have access to the Jakarta Commons library there is ObjectUtils.equals() and lots of other useful functions.

EDIT: misread the question initially

edited Dec 18 '12 at 13:06

Slava Semushin

answered Oct 08 '08 at 21:10

Matt

score 8 · Answer 3 · answered Sep 22 '15 at 19:35

8

If you are using <1.7 but have Guava available: Objects.equal(x, y)

answered Sep 22 '15 at 19:35

Sam Berry

3 Answers3