Decompile Java JAR using JD-GUI tutorial for beginners - December 2022 - 54a87bac

I download and extract the Java decompiler JD-GUI. I have a Java JDK installed from my Linux distribution, I download the newest Java JDK 19 from Oracle. I decompile JD-GUI jar file using JD-GUI. I tell JD-GUI to decompile the entire jar file and generate a directory with Java source code including Java project files. Such that a Java IDE can compile back to a jar file. I install IntelliJ IDEA Community. I navigate the generated source code using VS Code and IntelliJ IDEA Community. Unfortunately the decompiled Java source code has a number of Java compiler errors.