sudo apt install default-jdk
JDK와 JRE, JVM까지 모두 설치된다.
which java
readlink -f /usr/bin/java
vi ~./zsh
export JAVA_HOME=/usr/lib/jvm/java-11-openjdk-amd64
export PATH=$PATH:$JAVA_HOME/bin
source ~./zsh
java -version javac -version
sudo apt-get autoremove openjdk-11-jre
java -version