[lworld] RFR: 8377162: [lworld] getResourceAsStream() doesn't work in preview mode for exploded images [v2]

[Alan Bateman]

On Tue, 17 Feb 2026 11:19:57 GMT, David Beaumont <duke at openjdk.org> wrote:

>> Allow exploded module readers created for exploded system images to support preview mode.
>
> David Beaumont has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains five additional commits since the last revision:
> 
>  - Merge branch 'lworld' into jdk_8377162_exploded_modules/squashed
>  - revert unnecessary filter in ModulePatcher
>  - Latest version
>  - Limit awareness of preview resources to system modules only.
>    
>    * limit preview handling
>    * Patch ModuleReaderTest from mainline
>  - Preview mode for exploded system module readers
>    
>    * with better flag plumbing
>    * Simpler approach with linked hash set
>    * Revert weird import change
>    * First cut at a preview aware module reader for exploded builds
>    * Test for partiy of JRT file-system and class resources in preview mode

src/java.base/share/classes/jdk/internal/module/ModulePath.java line 121:

> 119:      * Returns a ModuleFinder for system modules in the {@code $JAVA_HOME/modules}
> 120:      * directory on the file system by searching a sequence of directories and/or
> 121:      * packaged modules. The modules may be patched by the given ModulePatcher.

There are no packaged modules in the interim exploded build. So I think better for this method description to say that it returns the ModuleFinder for an exploded JDK build where moduleDir is the $JAVA_HOME/modules directory.

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PR Review Comment: https://git.openjdk.org/valhalla/pull/2032#discussion_r2823189141