Hello, we were using protobuf-java library version 2.3.0 at our enterprise software, until recently several security vulnerabilities were found in this version and we have to upgrade it at some point.

Now, that gets very, very interesting because it, uh, requires a bit of knowledge of the hashCode method, and it also requires a little bit of knowledge of the equals method.

I have written posts about using Objects class: JDK 7: The New Objects Class and Java 7 Objects-Powered Compact Equals.

Equals and hashcode implementation in wrapper classes Wrapper classes override the equals() method to perform value-based comparisons rather than the reference comparison used by Object.equals().