can not decompile class javax.crypto.Cipher in jdk10 with FernFlower

[gMan1990]

• MyEclipse Enterprise Workbench
  Version: CI 2018.9.0
  Build id: 16.0.0-20180903
• ecd 3.1.1.201811062102
• java version "10.0.1" 2018-04-17
  Java(TM) SE Runtime Environment 18.3 (build 10.0.1+10)
  Java HotSpot(TM) 64-Bit Server VM 18.3 (build 10.0.1+10, mixed mode)

java.lang.NullPointerException
        at java.base/java.util.regex.Matcher.getTextLength(Matcher.java:1769)
        at java.base/java.util.regex.Matcher.reset(Matcher.java:416)
        at java.base/java.util.regex.Matcher.<init>(Matcher.java:253)
        at java.base/java.util.regex.Pattern.matcher(Pattern.java:1130)
        at org.sf.feeling.decompiler.util.UnicodeUtil.decode(UnicodeUtil.java:21)
        at org.sf.feeling.decompiler.fernflower.FernFlowerDecompiler.decompile(FernFlowerDecompiler.java:118)
        at org.sf.feeling.decompiler.fernflower.FernFlowerDecompiler.decompileFromArchive(FernFlowerDecompiler.java:164)
        at org.sf.feeling.decompiler.editor.BaseDecompilerSourceMapper.decompile(BaseDecompilerSourceMapper.java:314)
        at org.sf.feeling.decompiler.editor.BaseDecompilerSourceMapper.findSource(BaseDecompilerSourceMapper.java:168)
        at org.sf.feeling.decompiler.editor.DecompilerSourceMapper.findSource(DecompilerSourceMapper.java:72)
        at org.sf.feeling.decompiler.editor.JavaDecompilerClassFileEditor.doOpenBuffer(JavaDecompilerClassFileEditor.java:173)
        at org.sf.feeling.decompiler.editor.JavaDecompilerClassFileEditor.doOpenBuffer(JavaDecompilerClassFileEditor.java:148)
        at org.sf.feeling.decompiler.editor.JavaDecompilerClassFileEditor.doSetInput(JavaDecompilerClassFileEditor.java:358)
        at org.sf.feeling.decompiler.actions.OpenClassWithContributionFactory$OpenClassesAction.run(OpenClassWithContributionFactory.java:134)
        at org.eclipse.jface.action.Action.runWithEvent(Action.java:473)
        at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:565)
        at org.eclipse.jface.action.ActionContributionItem.lambda$4(ActionContributionItem.java:397)
        at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:86)
        at org.eclipse.swt.widgets.Display.sendEvent(Display.java:4247)
        at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1508)
        at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1531)
        at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:1516)
        at org.eclipse.swt.widgets.Widget.notifyListeners(Widget.java:1320)
        at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:4091)
        at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3712)
        at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine$5.run(PartRenderingEngine.java:1170)
        at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
        at org.eclipse.e4.ui.internal.workbench.swt.PartRenderingEngine.run(PartRenderingEngine.java:1059)
        at org.eclipse.e4.ui.internal.workbench.E4Workbench.createAndRunUI(E4Workbench.java:153)
        at org.eclipse.ui.internal.Workbench.lambda$3(Workbench.java:667)
        at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:336)
        at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:597)
        at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:148)
        at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:152)
        at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:196)
        at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:134)
        at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
        at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:388)
        at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:243)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.base/java.lang.reflect.Method.invoke(Method.java:564)
        at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:656)
        at org.eclipse.equinox.launcher.Main.basicRun(Main.java:592)
        at org.eclipse.equinox.launcher.Main.run(Main.java:1498)

?? which can ?? JD, Jad, CFR, Procyon??

[RobertZenz]

I'm not sure, but I believe FernFlower fails to decompile that class and the plugin does not handle that case very well. Have you tried another decompiler?

[helospark]

Problem probably is the modularization of JRE.

JarExtractor tries to extract the class file from jar file here
However in Java 9+ jrt-fs.jar no longer contains the classfile, it has been moved to the proprietary modules file in the JRE root.
This affects all of the JRE classes (and probably other modularized class files), however most have attached source in the src.zip shipped with the JRE, however javax classes seems to be missing it, causing this issue.

Solution could be to read using jrt scheme, like:

Path p = Paths.get(URI.create("jrt:/modules/java.base/javax/crypto/Cipher.class"));
byte[] bytes = Files.readAllBytes(p);

and write this to the temporary class file if we are dealing with modularized files.