Native dependency issue in the Java API on Ubuntu: undefined symbol: JniUtils...

[vatbub]

I am using the Java API  of Metashape, version 2.2.0. Everything is working fine on Windows, but when running on Linux, I am encountering something that seems like a native dependency issue. Here's a minimal code sample for demonstration (in Kotlin):

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class LoadErrorDemo {
    @Test
    fun demo() {
        // Make sure this is the first time we are loading the library
        assertFalse(isMetashapeLoaded())

        System.loadLibrary("metashape") // Copied from the sample file supplied with the library

        // File contains camera data exported in the AgisoftXML format
        val demoFile =
            File("/home/six-tb-drive/Frederik/STREEM/PrismTests/V8/camera_export_from_agisoft_3_16_04_2024.xml")

        val imageFolder = File("/home/six-tb-drive/Frederik/STREEM/PrismTests/V8/ExportForAgisoft")
        val imageFiles: List<File> = imageFolder.listFiles()!!
            .filter { it.extension.lowercase() in listOf("jpg", "jpeg", "png") }

        val document = Document()
        val chunk = document.addChunk()
        chunk.addPhotos(imageFiles.map { it.absolutePath }.toTypedArray(), DummyProgress)

        val importTask = ImportCameras()
        importTask.path = demoFile.absolutePath
        importTask.format = CamerasFormat.CamerasFormatXML
        importTask.apply(chunk, ConsoleProgress(lineSeparator = "\n"))

        // This is the part that fails
        chunk.cameras.forEach { camera ->
            println(camera.label)
        }
    }

    object DummyProgress : Progress {
        override fun progress(progress: Double) {
            println("Progress: $progress")
        }

        override fun status(status: String?) {
            println("Status: $status")
        }

        override fun aborted(): Boolean = false
    }
}

The code is launched with the following environment variables:

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LD_LIBRARY_PATH=/home/one-tb-drive/git/image-converter/metashape-java-api-2.2.0/jniLibs/linux64:$LD_LIBRARY_PATH

and the JVM is launched with the following VM parameters:

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-ea -Djava.library.path="/home/one-tb-drive/git/image-converter/metashape-java-api-2.2.0/jniLibs/linux64"

The code fails when it tries to enumerate the cameras (chunk.cameras.forEach { camera -> }) with the following error:

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/usr/lib/jvm/java-21-openjdk-amd64/bin/java: symbol lookup error: /home/one-tb-drive/git/image-converter/metashape-java-api-2.2.0/jniLibs/linux64/libmetashape.so: undefined symbol: _ZNK8JniUtils15createLongArrayERKSt6vectorIxSaIxEE

What I found out so far:
When unmangling the "undefined symbol", I found that the library fails to resolve JniUtils.createLongArray(). One assumption that I have is that the library is compiled with the JNI headers of Java 1.8 whereas I am using Java 21, which could cause discrepancies in the ABI. Unfortunately, I am heavily relying on newer Java features and am therefore unable to downgrade to Java 8.

My environment:

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$ java -version
java -version
openjdk version "21.0.6" 2025-01-21
OpenJDK Runtime Environment (build 21.0.6+7-Ubuntu-124.04.1)
OpenJDK 64-Bit Server VM (build 21.0.6+7-Ubuntu-124.04.1, mixed mode, sharing)

$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 24.04.2 LTS
Release:        24.04
Codename:       noble

I'd like to hear if anyone else has faced this issue and what a potential fix could be. Thanks!

[Alexey Pasumansky]

Hello vatbub,

Thank you for reporting the problem

We have implemented the fix JniUtils problem, it will be included to the next version update.