jrt file system now has /package and /modules directories

[Alan Bateman]

On 26/07/2015 01:29, Michael Hall wrote:
>> On Jul 25, 2015, at 12:10 PM, Alan Bateman <Alan.Bateman at oracle.com> wrote:
>>
>>
>> Just a heads-up that jdk9-b74 has a refresh of the jimage and jrt file system implementation.
> Have mostly just been following along on this a little with the early access releases. I was a little curious on this though so I cloned and built current jdk9.
> I have a simple jrt filesystem lister that I tried running getting…
>
> ~/jdk9/build/macosx-x86_64-normal-server-release/jdk/bin/java -cp . JRTLister
> java.nio.file.FileSystemNotFoundException: /Users/mjh/jdk9/build/macosx-x86_64-normal-server-release/jdk/lib/modules/bootmodules.jimage
> 	at jdk.internal.jrtfs.JrtFileSystem.checkExists(JrtFileSystem.java:87)
> 	at jdk.internal.jrtfs.JrtFileSystem.<init>(JrtFileSystem.java:102)
> 	at jdk.internal.jrtfs.JrtFileSystemProvider$1.<init>(JrtFileSystemProvider.java:113)
> 	at jdk.internal.jrtfs.JrtFileSystemProvider.getTheFileSystem(JrtFileSystemProvider.java:113)
> 	at jdk.internal.jrtfs.JrtFileSystemProvider.getFileSystem(JrtFileSystemProvider.java:131)
> 	at java.nio.file.FileSystems.getFileSystem(FileSystems.java:221)
> 	at JRTLister.main(JRTLister.java:13)
>
> Obviously finding JrtFileSystem but not modules/bootmodules.jimage?
>
Replace jdk/bin/java with images/jdk/bin/java in your path above and I 
expect it should work.

The jdk directory in the build output is the "exploded build". It's an 
intermediate step in the build before the JDK and JRE images are 
created. Many people working on the JDK use the exploded builds for 
quick edit-build-debug sessions and local testing but I don't think is 
used much beyond that.

JDK-8066860 [1] is tracking an update to the jrt file system to support 
exploded builds. Sundar has an initial patch but it's not in JDK 9 yet.

-Alan

[1] https://bugs.openjdk.java.net/browse/JDK-8066860