[jdk21u-dev] RFR: 8310049: Refactor Charset tests to use JUnit

[Justin Lu]

On Sun, 5 Oct 2025 17:41:13 GMT, Goetz Lindenmaier <goetz at openjdk.org> wrote:

> I backport this for parity with 21.0.10-oracle

test/jdk/java/nio/charset/Charset/IllegalCharsetName.java line 52:

> 50:         assertThrows(IllegalCharsetNameException.class,
> 51:                 () -> Charset.forName(name));
> 52:         assertThrows(IllegalCharsetNameException.class,

In _illegalCharsetsTest_ and _emptyCharsetsTest_, please consider changing the second instance of `Charset.forName` to `Charset.isSupported` which was a faulty conversion made in the original change. Otherwise if not in this PR, please consider back-porting [JDK-8369078](https://bugs.openjdk.org/browse/JDK-8369078) as well, thank you.

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PR Review Comment: https://git.openjdk.org/jdk21u-dev/pull/2296#discussion_r2411376021