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Java9 JNLP --add-opens not working

I created a simple test case for testing Java 9 Web Start with new modules. Unfortunately, Java 9 Web Start does not support -permit-illegal access by default, just like regular Java 9.

Java 9 Web Start assumes support for --add-opens (see https://bugs.openjdk.java.net/browse/JDK-8172986 ).

I am using Java 1.9.0_181_ea.

Here is my test class:

import java.awt.Toolkit; import java.lang.reflect.Method; import java.lang.IllegalAccessException; import java.lang.reflect.InvocationTargetException; public class Java9BreaksWhenTest { public static void main(String args[]) throws IllegalAccessException, InvocationTargetException { System.out.println("Hello World"); // Do some dangerous reflection Toolkit toolkit = Toolkit.getDefaultToolkit(); Class c = toolkit.getClass(); while(true) { Method m = null; try { m = c.getDeclaredMethod("setDesktopProperty", String.class, Object.class); } catch (NoSuchMethodException ex) { c = c.getSuperclass(); if (c!=null) continue; } catch (SecurityException ex) { ex.printStackTrace(); } if (m!=null) { m.setAccessible(true); m.invoke(toolkit, "awt.font.desktophints", null); System.out.println("desktop Properties changed."); } break; } } }

Here is my JNLP file which should make java.awt code available.

 <?xml version="1.0" encoding="UTF-8"?> <jnlp spec="1.0+" codebase="file:///home/smm/hcs/testcode" href="java9BreaksWhenTest.jnlp"> <information> <title>Java 9 Breaks When Test</title> <vendor>HCS</vendor> <homepage href="http://hcs.us.com"/> <description>Java 9 Breaks When Test</description> <description kind="short">Java 9 Breaks When Test</description> </information> <security><all-permissions/></security> <update check="timeout" policy="always"/> <resources> <j2se version="9" java-vm-args="--add-opens java.desktop/java.awt=ALL-UNNAMED" /> <jar href="Java9BreaksWhenTest.jar" main="true" download="eager"/> </resources> <application-desc main-class="Java9BreaksWhenTest"> </application-desc> </jnlp>

This is similar to what is discussed here ( How to pass the Java 9 flag '-permit-illegal access' to the Webstart application? However, this does not work. Running it in Java Web Start, I get the following error:

 Hello World java.lang.reflect.InvocationTargetException 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 jdk.javaws@9 /com.sun.javaws.Launcher.executeApplication(Launcher.java:1741) at jdk.javaws@9 /com.sun.javaws.Launcher.executeMainClass(Launcher.java:1677) at jdk.javaws@9 /com.sun.javaws.Launcher.doLaunchApp(Launcher.java:1525) at jdk.javaws@9 /com.sun.javaws.Launcher.run(Launcher.java:158) at java.base/java.lang.Thread.run(Thread.java:844) Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make protected final void java.awt.Toolkit.setDesktopProperty(java.lang.String,java.lang.Object) accessible: module java.desktop does not "opens java.awt" to unnamed module @1f749ac at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:337) at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:281) at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:198) at java.base/java.lang.reflect.Method.setAccessible(Method.java:192) at Java9BreaksWhenTest.main(Java9BreaksWhenTest.java:26) ... 9 more #### Java Web Start Error: #### Unable to make protected final void java.awt.Toolkit.setDesktopProperty(java.lang.String,java.lang.Object) accessible: module java.desktop does not "opens java.awt" to unnamed module @1f749ac java.lang.reflect.InaccessibleObjectException: Unable to make protected final void java.awt.Toolkit.setDesktopProperty(java.lang.String,java.lang.Object) accessible: module java.desktop does not "opens java.awt" to unnamed module @1f749ac at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:337) at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:281) at java.base/java.lang.reflect.Method.checkCanSetAccessible(Method.java:198) at java.base/java.lang.reflect.Method.setAccessible(Method.java:192) at Java9BreaksWhenTest.main(Java9BreaksWhenTest.java:26) 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 jdk.javaws@9 /com.sun.javaws.Launcher.executeApplication(Launcher.java:1741) at jdk.javaws@9 /com.sun.javaws.Launcher.executeMainClass(Launcher.java:1677) at jdk.javaws@9 /com.sun.javaws.Launcher.doLaunchApp(Launcher.java:1525) at jdk.javaws@9 /com.sun.javaws.Launcher.run(Launcher.java:158) at java.base/java.lang.Thread.run(Thread.java:844)

It is not clear to me where my error is and why java.awt.Toolkit is not available for use through Reflection.

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1 answer

Since Java 9 is not confusing enough, the correct answer is:

 <j2se version="9" java-vm-args="--add-opens=java.desktop/java.awt=ALL-UNNAMED" />

This is equivalent to the value in the JNLP file, but not on the command line!

On the command line, both:

 java --illegal-access=deny --add-opens java.desktop/java.awt=ALL-UNNAMED -cp . Java9BreaksWhenTest

and

 java --illegal-access=deny --add-opens=java.desktop/java.awt=ALL-UNNAMED -cp . Java9BreaksWhenTest

work right!

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Source: https://habr.com/ru/post/1271375/

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