RFR: JDK-8280168 Add Objects.toDefaultString

[Roger Riggs]

On Tue, 18 Jan 2022 23:15:20 GMT, Joe Darcy <darcy at openjdk.org> wrote:

> While it is strongly recommend to not use the default toString for a class, at times it is the least-bad alternative. When that alternative needs to be used, it would be helpful to have the implementation already available, such as in Objects.toDefaultString(). This method is analagous to System.identityHashCode.
> 
> Please also review the CSR: https://bugs.openjdk.java.net/browse/JDK-8280184

src/java.base/share/classes/java/util/Objects.java line 170:

> 168:      * {@return a string equivalent to the string returned by {@code
> 169:      * Object.toString} if that method is not overridden}
> 170:      *

The original Object.toString() invokes the hashCode() method.
Perhaps the spec should indicate that it calls IdentityhashCode() instead of hashCode().

Though not incorrect, in Valhalla, Not all objects have identity and will need to different implementation.

Are there any use cases in the JDK that will use this method?

-------------

PR: https://git.openjdk.java.net/jdk/pull/7139