RFR: 8265989: System property for the native character encoding name

[Joe Wang]

On Wed, 28 Apr 2021 22:24:31 GMT, Naoto Sato <naoto at openjdk.org> wrote:

> After some internal discussion, we thought it was good to expose the native environment's default character encoding, which Charset.defaultCharset() is currently based on. This way applications will have a better migration path after the [JEP 400](https://openjdk.java.net/jeps/400) is implemented, in which Charset.defaultCharset() will return UTF-8, but the value of this new system property will remain intact. A [CSR](https://bugs.openjdk.java.net/browse/JDK-8266075) has been filed with more detailed information.

src/java.base/share/classes/java/lang/System.java line 704:

> 702:      * <tr><th scope="row">{@systemProperty native.encoding}</th>
> 703:      *     <td>Character encoding name derived from the host environment and/or
> 704:      *     the user's settings. Setting this system property has no effect.</td></tr>

May be "This property is read-only" instead of "Setting this system property has no effect" to not confuse with "user's settings"?

test/jdk/java/lang/System/PropertyTest.java line 83:

> 81:                 {"java.runtime.version"},
> 82:                 {"java.runtime.name"},
> 83:                 {"native.encoding"},

Does this test differentiate between read-only and modifiable properties? "native.encoding" looks like it's explicitly overridable. Or do we need a test to verify it's not overridable?

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PR: https://git.openjdk.java.net/jdk/pull/3777