Compact source files should not cause package error when placed in subfolders

[LeducNic]

I am a teacher and I want to use Compact Source files in my courses. But since the students will have many programs to write, I want to place them in subfolders. Right now, when I do that, I get a compile error that the package does not match the folder where the Compact Source file is located : The declared package "" does not match the expected package "sandbox" Java(536871240) .

Is it possible to add the relative path of the Compact Source implicitly to the classpath/sourcepath while compiling/running/debugging the file? So each time a Compact Source is detected, only the relative path to that file is added, not all path to all Compact Source in the project. An option could be useful, like "Implicitly add relative path of Compact Source to sourcepath : true/false".

[fbricon]

could you attach a sample project showing the issue?

[fbricon]

Can you try setting "java.jdt.ls.javac.enabled": "on"? By default the ECJ compiler enforces the enclosing folder matches the package name. Javac is more lax about it.

[LeducNic]

When I enable the option, I get an error saying that I need JDK 25, which is the only one installed on my Debian 13. I installed Temurin JDK in /usr/lib/jvm/java-25-openjdk-amd64 but it was not detected. So I added it in my config and when I restart VSCode, the popup Opening Java Projects never terminate and when I clic check details, I see this in terminal:
aee1d442 Initialize Workspace [Done]
a4f6a00c Building [Done]

The code cannot be run and is not detected as Java since the syntax coloring doesn't work.

I attached a sample directory tree that I might get from my students and all the sample file should be able to compile/run/debug without error. I use the Open Folder on Demo25 in VSCode.

Demo25.zip

[fbricon]

can you check if /usr/lib/jvm/java-25-openjdk-amd64/release exists?
Can you attach your log files (Ctrl+Shift+P : Java: Open all log files)

[LeducNic]

The file /usr/lib/jvm/java-25-openjdk-amd64/release exist and there is the firsts lines of it:
IMPLEMENTOR="Debian"
JAVA_RUNTIME_VERSION="25.0.1+8-Debian-1deb13u1"
JAVA_VERSION="25.0.1"
JAVA_VERSION_DATE="2025-10-21"

Here is the two log files. I see that Java has crashed at the end of the log file with java.lang.IllegalAccessError: superclass access check failed: class org.eclipse.jdt.internal.javac.AvoidNPEJavacTypes (in unnamed module @0x5052fbd) cannot access class com.sun.tools.javac.model.JavacTypes (in module jdk.compiler) because module jdk.compiler does not export com.sun.tools.javac.model to unnamed module @0x5052fbd

client.log
log.log

[fbricon]

Can you try with the latest vscode-java prerelease? The add-opens flag has been added for com.sun.tools.javac.model

[LeducNic]

OK, the pre-release fix the error, but the openjdk25 is not automatically detected. I have the openJDK25 Debian package and not Temurin like I said in my previous message. After cleaning Java cache I don't seem to have error in my Java files, but when running a compact source, it seems that it is always the previous version that is it running:
v1 -> Run v1 then add print statement (v2) -> run output v1 -> add output on v2 (v3) -> run output v2 ...
No problem with files in packages.

[fbricon]

@LeducNic right I see the same thing, but that's a different problem. Can you open a ticket in https://github.com/microsoft/vscode-java-debug/issues?

[LeducNic]

Should VSCode auto-detect JDK25 in Debian? Do I need to open a ticket for that too?

[fbricon]

@LeducNic we rely on https://github.com/Eskibear/node-jdk-utils for automatic JDK detection, so if you get it fixed there, we'll automatically reap the benefits

[LeducNic]

I installed jdk-utils 0.6.0 and when I run it, the JDK is detected :
nleduc@Debian25:~/Téléchargements/Test$ npx jdk-utils
Listing JDKs: 17.148ms
Found: 1
[
{
homedir: '/usr/lib/jvm/java-25-openjdk-amd64',
isInPathEnv: true,
hasJavac: true,
version: { java_version: '25.0.1', major: 25 }
}
]

but in VSCode I get that error: