Get directory of compiled native image by GraalVM at runtime

Question

I compiled my Java application with (GluonFX which itself uses) GraalVM. How can I get the directory where my application binary resides at runtime? (not the users working directory)

• Before using GraalVMs native-image tool, I used to read System.getProperty("java.home") and deduced it from there. But this system property does not exist anymore.
• I tried to find another system property, but the directory of my application was in none.
• I tried to read environment variables and found System.getenv("_"), but as "_ contains the last program run", this does not feel stable.
• I tried to resolve Paths.get(".").toAbsolutePath() but this only returned the current working directory.

My end goal is to package this small application binary in a bigger application and this small application should call other applications which will get packaged next to it.

Answer 1

You can get the running path from java code like below

Path path = Path.of(
        Main.class.getProtectionDomain()
                .getCodeSource()
                .getLocation()
                .toURI()
).getParent();
System.out.println(path);

Please change the Main class to the class you use in your code.

There is another way too but that requires nativeimage dependency.

<dependency>
    <groupId>org.graalvm.nativeimage</groupId>
    <artifactId>library-support</artifactId>
    <version>23.0.1</version>
    <scope>provided</scope>
</dependency>

then call it like below

System.out.println("exe path:"+ProcessProperties.getExecutableName());

example output

oz-mint@ozmint-MACH-WX9:~/Downloads/my-gluon-application$ ./target/gluonfx/x86_64-linux/My\ Gluon\ Application 
exe path:/home/oz-mint/Downloads/my-gluon-application/target/gluonfx/x86_64-linux/My Gluon Application
Dec 30, 2023 3:22:52 PM com.sun.javafx.application.PlatformImpl startup
WARNING: Unsupported JavaFX configuration: classes were loaded from 'unnamed module @71c7db30'
Dec 30, 2023 3:22:53 PM com.gluonhq.attach.util.Platform <clinit>
INFO: [Gluon Attach] System Property javafx.platform is not defined. Platform will be set to Platform.DESKTOP

working example

References

• https://github.com/oracle/graal/issues/4216
• https://stackoverflow.com/a/71295418/175554

Answer 2

I can confirm that ozkanpakdils answer works. Meanwhile I found also another solution:

ProcessHandle.current().info().command()

This "returns the executable pathname of the process" (from its Javadoc).

I use it like this:

String appDirectory = ProcessHandle.current().info().command().map(Paths::get).orElseThrow().getParent().toAbsolutePath()