How to distribute DJL application¶

This is an example of how to create distribution package for DJL application.

In this example you will learn how to package your application that can avoid download native libraries at runtime in case you don't have internet access in production environment.

Gradle¶

Run/test application with gradle

cd development/fatjar

./gradlew run

Distribute with .zip or .tar file

./gradlew assembleDist

You will find both .zip and .tar file in build/distributions folder.

Create fatjar:

./gradlew shadowJar

java -jar build/libs/fatjar-1.0-SNAPSHOT-all.jar

Maven¶

Run/test application with maven

cd development/fatjar

mvn package
mvn exec:java

Create fatjar:

mvn package

java -jar target/fatjar-1.0-SNAPSHOT.jar

SBT¶

Run/test application with sbt

cd development/fatjar

sbt run

Create fatjar:

sbt assembly

java -jar target/fatjar-assembly-1.0-SNAPSHOT.jar

Testing offline mode¶

To ensure the application doesn't download the native dependencies at runtime, you can set system property: ai.djl.offline=true.

You can test offline mode with gradle or using java command line option:

cd development/fatjar

# for gradle
./gradlew run -Dai.djl.offline=true

# for maven
mvn package
mvn exec:java -Dai.djl.offline=true

If your os doesn't match your native library, you will see the follow error:

Loading:     100% |████████████████████████████████████████|
Exception in thread "main" ai.djl.engine.EngineException: Failed to load PyTorch native library
    at ai.djl.pytorch.engine.PtEngine.newInstance(PtEngine.java:82)
    at ai.djl.pytorch.engine.PtEngineProvider.getEngine(PtEngineProvider.java:40)
    at ai.djl.engine.Engine.getEngine(Engine.java:181)
    at ai.djl.Model.newInstance(Model.java:99)
    at ai.djl.repository.zoo.BaseModelLoader.createModel(BaseModelLoader.java:189)
    at ai.djl.repository.zoo.BaseModelLoader.loadModel(BaseModelLoader.java:152)
    at ai.djl.repository.zoo.Criteria.loadModel(Criteria.java:168)
    at com.examples.FatJar.main(FatJar.java:41)
Caused by: java.lang.IllegalStateException: Failed to save pytorch index file
    at ai.djl.pytorch.jni.LibUtils.downloadPyTorch(LibUtils.java:399)
    at ai.djl.pytorch.jni.LibUtils.findNativeLibrary(LibUtils.java:282)
    at ai.djl.pytorch.jni.LibUtils.getLibTorch(LibUtils.java:87)
    at ai.djl.pytorch.jni.LibUtils.loadLibrary(LibUtils.java:75)
    at ai.djl.pytorch.engine.PtEngine.newInstance(PtEngine.java:53)
    ... 7 more
Caused by: java.io.IOException: Offline model is enabled.
    at ai.djl.util.Utils.openUrl(Utils.java:457)
    at ai.djl.util.Utils.openUrl(Utils.java:443)
    at ai.djl.pytorch.jni.LibUtils.downloadPyTorch(LibUtils.java:394)
    ... 11 more