I have recently discovered that applications will no longer be able to access internal packages (sun.* and com.sun.*) in JDK 9. This is a major problem for my application as it requires access to some internal packages in order to work correctly.
In most cases, my need to access these internal classes is to work around "object leakage" in Swing that results in objects being created and held by Swing with no means of freeing these objects by any application action. In some cases, these "leaked" objects reference my application classloader via their protection domain, and this means that my application classloader cannot be garbage collected even if I remove all references to it from within my application. My application uses native DLLs that sometimes need to be replaced by new versions and these DLLs cannot be unloaded and reloaded unless the application classloader that loaded these DLLs has been garbage collected. The only workaround I have found for this problem is to use internal APIs together with reflection to locate the fields that are holding these internal "leaked" objects and set these fields to null. It is hard to provide a definitive list of all the internal packages that I need because the list tends to grow each time I use additional Swing functionality in my application. At present, the packages are: sun.awt.AppContext sun.awt.image.MultiResolutionToolkitImage$ObserverCache sun.awt.X11.XBaseWindow sun.lwawt.LWComponentPeer sun.java2d.pipe.BufferedContext sun.java2d.pipe.RenderQueue sun.java2d.pipe.hw.BufferedContextProvider In addition, my application is using some APIs from internal packages to access functionality that isn't available via official APIs. These aren't Swing or AWT packages, so this mailing list probably isn't the right place to go into details. Any suggestions for the correct list(s) to raise this issue would be appreciated. The packages are: com.sun.management.HotSpotDiagnosticMXBean sun.misc.Signal sun.misc.SignalHandler sun.nio.ch.ChannelInputStream Best regards, Simon Nash
