| Constructors of primitive wrapper objects (e.g. `new Boolean(true)` will be |
| [deprecated][8145468] in Java 9. The `valueOf` factory methods (e.g. |
| `Boolean.valueOf(true)`) should always be preferred. Those methods are called |
| implicitly by autoboxing, which is often more convenient than an explicit call. |
| `Integer x = Integer.valueOf(23);` and `Integer x = 23;` are equivalent. |
| |
| [8145468]: https://bugs.openjdk.java.net/browse/JDK-8145468 |
| |
| The explicit constructors always return a fresh instance, resulting in |
| unnecessary allocations. The `valueOf` methods return cached instances for |
| frequently requested values, offering significantly better space and time |
| performance. |
| |
| Relying on the unique reference identity of the instances returned by the |
| explicit constructors is extremely bad practice. Primitives should always be |
| treated as identity-less value types, even in their boxed representations. |
