Cross compile newer versions of Java (i.e. 11) to Java8 (and earlier)
| Project | Download | Status |
|---|---|---|
| Calimero Project (Core, Device, RXTX) | Latest success build |
Run downpile.bat existing.jar
If the jar file has dependencies just make sure they are in the same folder, or pass it as a --lib parameter to downpile like this
downpile.bat existing.jar --lib "lib\nrjavaserial-3.15.0.jar"The result is found in out/
The file build_calimero.bat shows how to build a series of dependent jars.
When running downpile it will run Google R8 to turn a jar into a dex file that is compatible with previous java versions. Then use dex2jar to turn that dex file back to a runnable jar. R8 will automatically desugar recent java features and missing classes.
The prepare script will:
- Download Java8 and Java11 ( https://adoptopenjdk.net/ )
- Download Google Depot Tools ( https://www.chromium.org/developers/how-tos/install-depot-tools )
- Download Google R8 and D8 ( https://r8.googlesource.com/r8 )
- Compile R8 and D8
- Download custom version of Dex2Jar because the original version has a problem with "unsafe" class names that R8 will create ( https://github.com/petero-dk/dex2jar )
- Compile dex2jar