On Tue, 15 Dec 2020 at 14:45, Martin Grigorov <mgrigo...@apache.org> wrote:
> Hi Chris, > > Thank you for your advices! > > On Mon, Dec 14, 2020 at 6:11 PM Chris Hegarty <chris.hega...@oracle.com> > wrote: > > > > > > On 14 Dec 2020, at 10:03, Rory O'Donnell <rory.odonn...@oracle.com> > > wrote: > > > > > > ... > > > On 14/12/2020 09:45, Martin Grigorov wrote: > > >> Hi Rory, > > >> > > >> Apache Wicket build and tests are OK with JDK 16 b28 for both aarch64 > > and > > >> x86_64 (Ubuntu 20.10)! > > >> > > >> I had to add --add-opens=java.base/java.io=ALL-UNNAMED to > > >> maven-surefire-plugin's JVM arguments because it seems this plugin > does > > not > > >> use the (automatic) module name of the Maven project and the JDK sees > > it as > > >> unnamed. > > >> And because of this Wicket was not able to install its hooks into Java > > >> Serialization API. > > >> > > >> > > > https://github.com/apache/wicket/commit/b269b6dcc6a7642c5b5211cae60c7fa24dd7e7ef__;!!GqivPVa7Brio!OG8UiKWp8imcsbWbsHgnGZT9g23KrXftUL9elEebSECla8O_rUMab08gGqzzNApXj5k$ > > > > Opening the `java.io` package will of course work, but requires all > > deployments of Wicket to do so. Maybe there is a better alternative. > > > > > Actually there is no problem. > The unit tests were failing because of 'module java.base does not "opens > java.io" to unnamed module'. > It seems maven-surefire-plugin does not use the Maven module's (automatic) > module name while running the tests and the JVM sees it as "unnamed". > So, I've added the exception to maven-surefire-plugin's JVM args: > > https://github.com/apache/wicket/blob/b269b6dcc6a7642c5b5211cae60c7fa24dd7e7ef/pom.xml#L1086-L1097 > If I deploy a .war file to a web container like Apache Tomcat then there is > no such exception at runtime. I haven't verified but I guess all is fine > due to the Automatic-Module-Name in META-INF/MANIFEST.MF ( > > https://github.com/apache/wicket/blob/b269b6dcc6a7642c5b5211cae60c7fa24dd7e7ef/pom.xml#L989-L1004 > ) > > According to catalina.out Tomcat9 adds "--add-opens=jva.base/java.io=ALL-UNNAMED" as well as many others .... > > > I see that `org.apache.wicket.serialize.java.JavaSerializer` is using > > `setAccessible(true)` to access the private static method > > `latestUserDefinedLoader` in `java.io.ObjectInputStream`. There is a > > straightforward way of implementing similar functionality with the > > standard java.lang.StackWalker API. If you do this, then the > > `--add-opens` can probably be dropped. > > > > I will try to improve this with your suggestion! > > But the problem I solved was for > > https://github.com/apache/wicket/blob/b269b6dcc6a7642c5b5211cae60c7fa24dd7e7ef/wicket-core/src/main/java/org/apache/wicket/core/util/objects/checker/CheckingObjectOutputStream.java#L251-L282 > Here Wicket uses Reflection for ObjectStreamClass and ObjectStreamField to > be able to pinpoint which member field of a Java object is not Serializable > for debugging purposes. > > > > > > Here is an example of such: > > > > static { > > PrivilegedAction<StackWalker> pa1 = > > () -> > > StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE); > > PrivilegedAction<ClassLoader> pa2 = > > () -> ClassLoader.getPlatformClassLoader(); > > STACKWALKER = AccessController.doPrivileged(pa1); > > PLATFORM_LOADER = AccessController.doPrivileged(pa2); > > } > > > > /** > > * Returns the first non-null and non-platform class loader (not > > counting > > * class loaders of generated reflection implementation classes) up > the > > * execution stack, or the platform class loader if only code from > the > > * bootstrap and platform class loader is on the stack. > > */ > > private static ClassLoader latestUserDefinedLoader() { > > return STACKWALKER.walk(s -> > > s.map(StackWalker.StackFrame::getDeclaringClass) > > .map(Class::getClassLoader) > > .filter(Objects::nonNull) > > .filter(cl -> !PLATFORM_LOADER.equals(cl)) > > .findFirst() > > .orElse(PLATFORM_LOADER)); > > } > > > > Remove the PrivilegedAction / doPrivileged stuff if not interested in > > running with a security manager enabled. > > > > Let me know if I can do anything further to help. > > > > -Chris. > > > > > -- Best regards, Maxim
