DatatypeConverter was deprecated in Java 9 and has been removed in Java 11. Instead of DatatypeConverter#printHexBinary we use the equivalent method Hex#encodeHexString from the commons-codec library, which we already require anyway (see build.sh).
(My problem is, that I need to run Arduino IDE on Java 11 (or maybe 10), because otherwise the Serial Monitor won't work, and I need to run Arduino IDE on Java 8 (or maybe 9), to upload certificates via this plug-in. Since my change should make it work on all Java versions, I thought it would be a useful contribution.)
DatatypeConverter was deprecated in Java 9 and has been removed in Java 11. Instead of DatatypeConverter#printHexBinary we use the equivalent method Hex#encodeHexString from the commons-codec library, which we already require anyway (see build.sh).
(My problem is, that I need to run Arduino IDE on Java 11 (or maybe 10), because otherwise the Serial Monitor won't work, and I need to run Arduino IDE on Java 8 (or maybe 9), to upload certificates via this plug-in. Since my change should make it work on all Java versions, I thought it would be a useful contribution.)