RFR: 8331467: FileSystems.getDefault fails with ClassNotFoundException if custom default provider is in run-time image [v8]

[Alan Bateman]

On Thu, 19 Dec 2024 09:23:27 GMT, liyazzi <duke at openjdk.org> wrote:

>> For two cases:
>> 
>> 1. When the ImageReaderFactory was loaded by local jdk,that means the ImageReaderFactory was loaded by boot class loader,then init the `Path BOOT_MODULES_JIMAGE` by using `sun.nio.fs.DefaultFileSystemProvider` which is obtained through reflection,due to it is in jdk internal.
>> 2. When loaded by a target jdk, such as jdk8 runtime, then use the Java 8 compatible APIs: `FileSystems.getDefault()` to init the `BOOT_MODULES_JIMAGE` field.
>> Then we can avoid the circular dependencies in class loading caused by loading the defaultSystemProvider.
>
> liyazzi has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 17 commits:
> 
>  - Enable the 'testFspInRuntimeImage' test in SetDefaultProvider
>  - Merge branch 'master' of github.com:liyazzi/jdk into 8331467
>  - revert the SetDefaultProvider
>  - Merge branch 'openjdk:master' into 8331467
>  - add test case in test/jdk/java/nio/file/spi/SetDefaultProvider.java as the test of this issue
>  - add '\s' to avoid trailing whiteSpace
>  - empty commit
>  - remove the '\s' and trailing whitespace
>  - add test.jdk value log
>  - deal with trailing whitespace
>  - ... and 7 more: https://git.openjdk.org/jdk/compare/23d6f747...ebf6b1da

I'm happy with the current changes in the PR. The copyright header date in ImageReaderFactory can be updated to 2024, and the import of Disabled can be removed from the SetDefaultProvider test.

To your question about tests then it's possible. The test that has been enabled in this change is the main test we will to ensure this configuration works. So I think we can leave further tests in this area to further PRs.

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PR Review: https://git.openjdk.org/jdk/pull/22628#pullrequestreview-2514190709