Compare two objects with a check for null

Solution 1:

Java 7.0 added a new handy class: Objects.

It has a method exactly for this: Objects.equals(Object a, Object b)

Solution 2:

Apache Commons Lang has such a method: ObjectUtils.equals(object1, object2). You don't want generics on such a method, it will lead to bogus compilation errors, at least in general use. Equals knows very well (or should - it is part of the contract) to check the class of the object and return false, so it doesn't need any additional type safety.

Solution 3:

FWIW, this was my implementation:

private static boolean equals(Object a, Object b) {
    return a == b || (a != null && a.equals(b));
}

In my application, I know that a and b will always be the same type, but I suspect this works fine even if they aren't, provided that a.equals() is reasonably implemented.

Solution 4:

public static boolean equals(Object object1, Object object2) {
    if (object1 == null || object2 == null) {
        return object1 == object2;
    }
    return object1.equals(object2);
}