PS Please also review the CSR
https://bugs.openjdk.java.net/browse/JDK-8223265
Note that the particular implementation used in Objects.equals was
recommended in its initial code review back in 2009:
http://mail.openjdk.java.net/pipermail/core-libs-dev/2009-September/002580.html
Thanks,
-Joe
On 5/2/2019 2:42 PM, Joe Darcy wrote:
Hello,
Bug JDK-8223112 notes indirectly that if Objects.equals is called with
(foo, null) and foo has a buggy equals method that returns true for
null, the wrong result will be computed.
I don't think code should be added to Objects.equals itself to guard
against this case. Instead, I think the operational semantics of the
implementation should be made explicit in the specification.
Please review the patch below.
Thanks,
-Joe
diff -r 7ab4310ed472 src/java.base/share/classes/java/util/Objects.java
--- a/src/java.base/share/classes/java/util/Objects.java Wed May 01
20:25:31 2019 -0700
+++ b/src/java.base/share/classes/java/util/Objects.java Thu May 02
14:41:06 2019 -0700
@@ -62,10 +62,11 @@
* Returns {@code true} if the arguments are equal to each other
* and {@code false} otherwise.
* Consequently, if both arguments are {@code null}, {@code true}
- * is returned and if exactly one argument is {@code null}, {@code
- * false} is returned. Otherwise, equality is determined by using
- * the {@link Object#equals equals} method of the first
- * argument.
+ * is returned. Otherwise, if the first argument is not {@code
+ * null}, equality is determined by calling the {@link
+ * Object#equals equals} method of the first argument with the
+ * second argument of this method. Otherwise, {@code false} is
+ * returned.
*
* @param a an object
* @param b an object to be compared with {@code a} for equality
...
public static boolean equals(Object a, Object b) {
return (a == b) || (a != null && a.equals(b));
}
