sudo apt install openjdk-21-jdk -y sudo apt search openjdk-.*-jdk$
sudo update-alternatives --config java
java -version
sudo vi /etc/profile.d/java_home.sh export JAVA_HOME=`echo $(dirname $(readlink $(readlink $(which java)))) | sed -e 's/\/bin$//g' | sed -e 's/\/jre$//g'` source /etc/profile.d/java_home.sh echo $JAVA_HOME

https://www.eclipse.org/downloads/packages/ tar zxvf ./eclipse-inst-jre-linux64.tar.gz cd eclipse-installer ././eclipse-inst
http://mergedoc.sourceforge.jp/
unzip pleiades.zip
cp -r ./features/ ~/eclipse/java-2022-12/eclipse/.
cp -r ./plugins/ ~/eclipse/java-2022-12/eclipse/.
cd ~/eclipse/java-2022-12/eclipse
cp eclipse.ini eclipse.ini.org
vim eclipse.ini
-Xverify:none
-javaagent:/home/devuser/eclipse/java-2022-12/eclipse/plugins/jp.sourceforge.mergedoc.pleiades/pleiades.jar
cd /home/devuser/eclipse/java-2022-12/eclipse
./eclipse