java don't outputs sound to pulse audio by default

[ilya paschuk]

package: openjdk-17-jre

steps to reproduce

write a clean raspberry pi os bullseye image
update all packages
install pulseaudio and openjdk-17-jre
use any java application which uses java sound api for playback
when playback is running, call pactl list sink-inputs

expected behavior:
sink input should be in the list

actual behavior:
nothing in the returned list

an other way to demonstrate this is to connect any bluetooth headphones and try to play sound from java

expected:
sound should go through the bluetooth device

actual:
sound go through the standard audio jack

it is not working because Java ignores pulse and sends it's output to alsa directly

possible fix:

append the following lines to /etc/java-17-openjdk/sound.properties

javax.sound.sampled.Clip=com.sun.media.sound.DirectAudioDeviceProvider
javax.sound.sampled.Port=com.sun.media.sound.PortMixerProvider
javax.sound.sampled.SourceDataLine=com.sun.media.sound.DirectAudioDeviceProvider
javax.sound.sampled.TargetDataLine=com.sun.media.sound.DirectAudioDeviceProvider

it fixes the problem, but I don't understand why

java 17 from the repository, raspberry pi os bullseye 64 bit, raspberry pi 4 model b