$ sudo add-apt-repository ppa:webupd8team/java sudo: add-apt-repository: command not found add-apt-repositoryがないと言われたら、software-properties-commonをインストールする。python-software-propertiesも必要なので入れる。 $ sudo apt-get install software-properties-common python-software-properties $ sudo add-apt-repository ppa:webupd8team/java $ sudo apt-get update $ sudo apt-get install oracle-java8-installer
![UbuntuにJava8をインストールする - Qiita](https://cdn-ak-scissors.b.st-hatena.com/image/square/f9c306353536c3a78437bb352198bff8f3500ab9/height=288;version=1;width=512/https%3A%2F%2Fqiita-user-contents.imgix.net%2Fhttps%253A%252F%252Fcdn.qiita.com%252Fassets%252Fpublic%252Farticle-ogp-background-412672c5f0600ab9a64263b751f1bc81.png%3Fixlib%3Drb-4.0.0%26w%3D1200%26mark64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZ3PTk3MiZoPTM3OCZ0eHQ9VWJ1bnR1JUUzJTgxJUFCSmF2YTglRTMlODIlOTIlRTMlODIlQTQlRTMlODMlQjMlRTMlODIlQjklRTMlODMlODglRTMlODMlQkMlRTMlODMlQUIlRTMlODElOTklRTMlODIlOEImdHh0LWFsaWduPWxlZnQlMkN0b3AmdHh0LWNvbG9yPSUyMzIxMjEyMSZ0eHQtZm9udD1IaXJhZ2lubyUyMFNhbnMlMjBXNiZ0eHQtc2l6ZT01NiZzPTEyZTAyYjhkMDhkZjc0ZmQyNTFlYTEwZjNiYjAyNWY3%26mark-x%3D142%26mark-y%3D57%26blend64%3DaHR0cHM6Ly9xaWl0YS11c2VyLWNvbnRlbnRzLmltZ2l4Lm5ldC9-dGV4dD9peGxpYj1yYi00LjAuMCZoPTc2Jnc9NzcwJnR4dD0lNDBzdHJzayZ0eHQtY29sb3I9JTIzMjEyMTIxJnR4dC1mb250PUhpcmFnaW5vJTIwU2FucyUyMFc2JnR4dC1zaXplPTM2JnR4dC1hbGlnbj1sZWZ0JTJDdG9wJnM9YzJiOTYzYjRhNjcyYjQ5MDY2MmFjMDVkMTNkZTdkOTQ%26blend-x%3D142%26blend-y%3D486%26blend-mode%3Dnormal%26s%3Db6c5d1d13d70d166fc348128d13aedb5)