関連ワード:  linux install java 21 ubuntu    how to install java 21 ubuntu    how to install java 21 ubuntu server    how to install jdk 21 ubuntu    how to install java 21 on ubuntu 24.04    how to install java 21 on ubuntu 22.04    how to install java 21 on ubuntu 20.04    how to install java 21 in ubuntu using terminal    how to install java 21 on ubuntu 18.04    how to install java 21 on ubuntu 22