I tried to run jrtfsviewer.js and jrtls.js . But they did not work as below:
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$ jjs -fx jrtfsviewer.js
Exception in Application start method
Exception in thread "main" java.lang.RuntimeException: Exception in Application start method
        at com.sun.javafx.application.LauncherImpl.launchApplication1(javafx.graphics@9-ea/LauncherImpl.java:897)
        at com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(javafx.graphics@9-ea/LauncherImpl.java:188)
        at java.lang.Thread.run(java.base@9-ea/Thread.java:843)
Caused by: java.lang.NullPointerException
        at java.util.Objects.requireNonNull(java.base@9-ea/Objects.java:221)
        at jdk.internal.jrtfs.JrtFileSystemProvider.newFileSystem(java.base@9-ea/JrtFileSystemProvider.java:104)
        at java.nio.file.FileSystems.newFileSystem(java.base@9-ea/FileSystems.java:342)
        at jdk.nashorn.internal.scripts.Script$Recompilation$22$3116$jrtfsviewer$cu1$restOf.getJrtFileSystem(jdk.scripting.nashorn.scripts/jrtfsviewer.js:103)
        at jdk.nashorn.internal.scripts.Script$Recompilation$17$3748A$jrtfsviewer.start(jdk.scripting.nashorn.scripts/jrtfsviewer.js:109)
        at jdk.nashorn.internal.scripts.Script$Recompilation$6$839A$\=fx\!bootstrap$cu1$restOf.start(jdk.scripting.nashorn.scripts/fx:bootstrap.js:57)
        at jdk.nashorn.javaadapters.javafx_application_Application.start(Unknown Source)
        at com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(javafx.graphics@9-ea/LauncherImpl.java:843)
        at com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(javafx.graphics@9-ea/PlatformImpl.java:452)
        at com.sun.javafx.application.PlatformImpl.lambda$runLater$10(javafx.graphics@9-ea/PlatformImpl.java:421)
        at java.security.AccessController.doPrivileged(java.base@9-ea/Native Method)
        at com.sun.javafx.application.PlatformImpl.lambda$runLater$11(javafx.graphics@9-ea/PlatformImpl.java:420)
        at com.sun.glass.ui.InvokeLaterDispatcher$Future.run(javafx.graphics@9-ea/InvokeLaterDispatcher.java:96)
        at com.sun.glass.ui.win.WinApplication._runLoop(javafx.graphics@9-ea/Native Method)
        at com.sun.glass.ui.win.WinApplication.lambda$runLoop$3(javafx.graphics@9-ea/WinApplication.java:189)
        ... 1 more
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$ jjs jrtls.js
jrtls.js:37:1 Expected an operand but found *
 */
 ^
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These scripts are not in JDK. But I think it should be fixed.