Internal JDK APIs Unavailable In Java 9

With Java 9 coming we have to prepare for several big changes which will affect NetBeans and might break the code. One such change is that bunch of internal APIs from JDK 8 and older will become really JDK internal and will not be accessible from NetBeans. Internal APIs will not be accessible when JDK 9 module boundaries will be in place. We have to therefore replace these APIs with new one. This document serves for tracking NetBeans packages which are affected, list some already published replacement/workarounds. We will use this doc to make sure NetBeans version supposed to be running on Java 9 will be ready on time re internal API usage.

jdeps tool

We used jdeps tool to search for what Java internal APIs we are using. It lists also some examples how to replace obsolete internal APIs with new public ones. It is recommended that every NetBeans module developer runs jdeps on his modules and does not depend solely on this table.

sun.* packages

APIs under sun.* will be Java private one and will not be accessible from within NetBeans sources. Here is the list of NetBeans modules and what sun.* packages were found.

Owner ( Resolved or Comment NetBeans module Internal Java API being used
mromashova dlight.remote, sun.swing.FilePane, un.swing.WindowsPlacesBar
phejl 531fa1e769e4 & bbee05e260e5 glassfish.common sun.misc.BASE64Encoder,
phejl 3ffa0f3e9bc1 web.jspparser sun.misc.SharedSecrets, sun.misc.ClassLoaderUtil
thurka jconsole sun.jvmstat.monitor.*,,
thurka lib.profiler sun.jvmstat.monitor.*
thurka profiler.heapwalker sun.misc.VM
thurka profiler.snaptracer sun.swing.plaf.synth.SynthIcon
thurka lib.profiler.charts sun.swing.SwingUtilities2
thurka false positive profiler.oql sun.misc.Ref
thurka sampler
thurka traceio sun.misc.IoTrace
mentlicher Removed usage of sun.reflect.DelegatingClassLoader and sun.font.*

sun.awt.X11.* is accessed by reflection only.

debugger.jpda sun.reflect.DelegatingClassLoader, sun.font.AttributeMap, sun.reflect.ReflectionFactory, sun.awt.X11.XAwtState, sun.awt.X11.XBaseWindow, sun.awt.X11.XToolkit, sun.awt.X11.XAtom
mentlicher Used as a String only, no action required. debugger.jpda.visual sun.misc.Launcher$AppClassLoader
tstupka 64a2aa2f744c kenai sun.misc.BASE64Encoder
tmysik b98e9b6e607c php.dbgp sun.misc.BASE64Encoder
mentlicher (ovrabec) o.n.swing.dirchooser
mentlicher (ovrabec) o.n.swing.dirchooser sun.swing.WindowsPlacesBar
mentlicher (ovrabec) openide.util sun.awt.AppContext
mentlicher (jpeska) Used as a String only, no action required. openide.explorer sun.beans.editors.EnumEditor
mentlicher (jhavlin) Tests only openide.filesystems,
lfischmeistr DefaultProxySelector - OK, NetProperties - core-main/635cc7828e1e,
lfischmeistr o.n.bootstrap sun.awt.AppContext
mentlicher (saubrecht) Need and

Removed usage of sun.swing.plaf.synth.SynthIcon sun.awt.X11.XToolkit, sun.awt.X11.XWM, sun.swing.plaf.synth.SynthIcon
mentlicher (saubrecht) 8a9c81481e91 o.n.swing.plaf sun.swing.plaf.synth.SynthUI
mmetelka editor sun.awt.AppContext
mmetelka openide.text,
mkristofic spi.editor.hints sun.swing.plaf.synth.SynthIcon

com.sun.* packages

Some packages from com.sun will become public API in Java 9. These are:

  • com.sun.source.*
  • com.sun.jdi
  •* is exported, subpackages will be internal

As the source of intermediate info about what packages will be exported from Java 9 you can refer to modules.xml for Java 9 modules being API. This info/mechanism can change (modules.xml can be replaced by something different) once Java 9 implementation proceeds further to Feature complete and release. Following table lists NetBeans modules which utilizes com.sun.* internal APIs which will be internal in Java 9. com.sun.source usage and com.sun.jdi usage were removed from this list.

Owner ( Resolved/Comment NetBeans module Internal Java API being used
petrk cnd.modelimpl*,*
phejl These are not JDK classes. web.el com.sun.el.parser.*
phejl These are not JDK classes. web.jsf.editor com.sun.faces.*
thurka jconsole com.sun.jmx.*
mentlicher debugger.jpda.visual*
mentlicher debugger.jpda.visual com.sun.javafx.runtime.*
mentlicher debugger.jpda.visual*
jstola These are not JDK classes. websvc.**,*, com.sun.xml.rpc.*
jstola core.browser.webview com.sun.javafx.scene.web.Debugger
mentlicher (mkozeny) These are not JDK classes. apisupport.feedreader com.sun.syndication.*
mentlicher (saubrecht) should be OK o.n.swing.plaf,
lfischmeistr should be OK o.n.bootstrap com.sun.jnlp.JNLPClassLoader
lfischmeistr should be OK core.startup,,
sdedic java.source* - Listed for completness, nbjavac contains this. (only this package exported, subpackages are not)
rsvitanic old ME 3.x support - on UC for old releases only deployment.deviceanywhere
 ? form
 ? javacard.* com.sun.javacard.*
N/A? identity.profile.api com.sun.identity.*


It should be be possible to use reflection to call Java internal APIs even after module boundaries will be in place. It will be likely necessary to call setAccessible(true) for elements which needs to be called via reflection. At this moment it is not 100% confirmed it will work this way or setAccessible(true) will be needed.

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