Docs

• Wiki and Reasoning https://github.com/remkop/picocli/wiki/Build-great-native-CLI-apps-in-Java-with-GraalVM-and-Picocli
• Annotation processor can be use to create a reflection config file. This is required in order to tell GraalVM what reflection is required. (Reflection does not worth with ahead of time compilation).
  • https://github.com/remkop/picocli/blob/master/RELEASE-NOTES.md#-annotation-processor
  • https://picocli.info/#_annotation_processor
  • Annotation processor create a config files (in target/classes/META-INF/native-image) required to build a native image using graalvm
  • How to use (tested for maven): https://github.com/remkop/picocli/tree/master/picocli-codegen#ide
  • We are setting it as part of maven-compiler-plugin in pom.xml

Limitations:

• GraalVM does not currently support cross-compilation. a.k.a. you need a windows hows to compile to windows.
  • oracle/graal#1446
• Tested only with Java 8

Building:

• mvn clean install (this will also generate the reflection config file)
• docker run -it -v C:\dev\trees\cli_file_manager:/usr/games oracle/graalvm-ce tail -f /dev/null
  • Creates a running container with graalvm installed in it
• exec into container
  • gu install native-image
  • cd /usr/games
  • ./build_native.sh
  • Output is fmcli
  • To test runtime duration: time ./fmcli file src dst

Future research:

• Command line TAB completion: https://picocli.info/autocomplete.html
• Has support for spring ... but do i really need that? Plus it includes spring classes to compiled file.
• Interactive password can be done easily: https://picocli.info/#_interactive_password_options