trouble geting jlink to load a module

Question

I am following through a Java textbook, and is stuck when running some example code that uses Jlink to "create a runtime image" of a group of modules.

I have a directory structure that looks kind of like this, with appfuncs and appstart being 2 modules that I have defined where appstart requires the appfuncs module, and appstart also contains the point of entry main class, MyModAppDemo.java.

When I run the jLink command below, i get an error that says that the mymodapp module cannot be loaded.

jlink --launcher MyModApp=appstart/appstart.mymodappdemo.MyModAppDemo --module-path "%JAVA_HOME%"\jmods;mymodapp\appmodules --add-modules appstart --output mylinkedmodapp

The error:

I hope to get some idea of what this error is about, if I am missing something that is really fundamental I am really sorry, I'm not very proficient with Java.

Answer 1

What you're seeing is a powershell error, not a Java error.

The issue is that in powershell, ; is used to delimit commands. To prevent that, you need to use quotes. Furthermore, you can't use %JAVA_HOME% in powershell to access environment variables. You need to use $Env:JAVA_HOME instead. This should work:

jlink --launcher MyModApp=appstart/appstart.mymodappdemo.MyModAppDemo --module-path "$Env:JAVA_HOME\jmods;mymodapp\appmodules" --add-modules appstart --output mylinkedmodapp