Bugzilla – Bug 1074162
java-9-openjdk-headless: jrt-fs.jar not compatible with Java 8
Last modified: 2022-04-07 08:54:34 UTC
The `jrt-fs.jar` shipped in `java-9-openjdk-headless` package is not compatible with Java 8, which is apparently necessary for some development tools that themselves run on Java 8 to be able to use the Java 9 JDK shipped in this package.
One example of this is Intellij IDEA, which means currently it's unable to use openSUSE provided Java 9 JDK as a project JDK.
A detailed explanation of the issue can be found on OpenJDK bugtracker  and also a test program and steps to reproduce can be found on Ubuntu bugtracker for their corresponding package .
The steps are:
1. zypper in java-9-openjdk-headless java-1_8_0-openjdk-headless
2. download `ReadJrt.java` from 
3. /usr/lib64/jvm/java-1.8.0/bin/javac ReadJrt.java
4. /usr/lib64/jvm/java-1.8.0/bin/java ReadJrt /usr/lib64/jvm/java-9/
Also relevant bug in Intellij IDEA: https://youtrack.jetbrains.com/issue/IDEA-179481