使用 Kubuntu。
cat /etc/issue
Ubuntu 17.04 \n \l
现在假设我们已经安装了 default-jdk 包：
apt show default-jdk
Package: default-jdk
Version: 2:1.8-57ubuntu1
Priority: optional
Section: devel
Source: java-common (0.57ubuntu1)
Origin: Ubuntu
Maintainer: Ubuntu Developers <[email protected]>
Original-Maintainer: Debian Java Maintainers <[email protected]>
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Installed-Size: 6'144 B
Provides: java-sdk, java2-sdk, java5-sdk, java6-sdk, java7-sdk, java8-sdk
Depends: default-jre (= 2:1.8-57ubuntu1), default-jdk-headless (= 2:1.8-57ubuntu1), openjdk-8-jdk
Homepage: https://wiki.debian.org/Java/
Supported: 9m
Download-Size: 968 B
APT-Manual-Installed: yes
APT-Sources: http://ch.archive.ubuntu.com/ubuntu zesty/main amd64 Packages
Description: Standard Java or Java compatible Development Kit
This dependency package points to the Java runtime, or Java compatible
development kit recommended for this architecture, which is
openjdk-8-jdk for amd64.
这里说“提供 java7-sdk”。我如何使用该 sdk？