RFR: 8350880: (zipfs) Add support for read-only zip file systems [v3]

[Lance Andersen]

On Mon, 12 May 2025 10:16:33 GMT, David Beaumont <duke at openjdk.org> wrote:

>> Adding read-only support to ZipFileSystem.
>> 
>> The new `accessMode` environment property allows for readOnly and readWrite values, and ensures that the requested mode is consistent with what's returned.
>> 
>> This involved a little refactoring to ensure that "read only" state was set initially and only unset at the end of initialization if appropriate.
>> 
>> By making 2 methods return values (rather than silently set non-final fields as a side effect) it's now clear in what order fields are initialized and which are final (sadly there are still non-final fields, but only a split of this class into two types can fix that, since determining multi-jar support requires reading the file system).
>
> David Beaumont has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Fix comment based on current behaviour.

test/jdk/jdk/nio/zipfs/NewFileSystemTests.java line 207:

> 205:                         Map.of("create", true, "accessMode", "badValue")));
> 206:     }
> 207: 

You could simplify the above tests using a DataProvider similar to

@DataProvider(name = "zipfsMap")
protected Object[][] zipfsMap() {
    return new Object[][]{
            {Map.of(), NoSuchFileException.class},
            {Map.of("accessMode", "readOnly"), NoSuchFileException.class},
            {Map.of("accessMode", "readWrite"),  NoSuchFileException.class},
            {Map.of("create", true, "accessMode", "readOnly"),  IllegalArgumentException.class},
            {Map.of("create", true, "accessMode", "badValue"),  IllegalArgumentException.class},
    };
@Test(dataProvider = "zipfsMap”)
public void testZipFSCreationException(Map<String, String> env, Class<T> exception) throws Exception {
       assertThrows(exception, () -> FileSystems.newFileSystem(noSuchZip, env));
}

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PR Review Comment: https://git.openjdk.org/jdk/pull/25178#discussion_r2089378491