ubuntu如何在线安装java7?

Question

root@localhost:~# sudo apt-get install oracle-java7-installer

sudo: unable to resolve host localhost.localdomain
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package oracle-java7-installer

Answer 1

sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update && sudo apt-get install oracle-java7-installer

Answer 2

貌似你还没有配好source list

首先，备份你的sources.list

sudo cp /etc/apt/sources.list /etc/apt/sources.list.bak

你搜索 "ubuntu 你的ubuntu版本号 source list"。以ubuntu 12.04为例，搜到的网易源为：

deb http://mirrors.163.com/ubuntu/ precise main universe restricted multiverse
deb http://mirrors.163.com/ubuntu/ precise-security universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ precise-updates universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ precise-proposed universe main multiverse restricted
deb http://mirrors.163.com/ubuntu/ precise-backports universe main multiverse restricted

然后用你喜欢的编辑器打开 /etc/apt/sources.list，清空文件，然后把上面的源列表贴到此文件中，保存。
和软件仓库同步：
```
sudo apt-get update
```
我猜想你要安装的是jdk，可以用 sudo apt-cache search jdk 搜索。可能有多个jdk可选，其中肯定有openjdk。具体名字我不知道，因为我现在不用ubuntu。
选择好你要安装的包，比如你选择的jdk包的名字是openjdk7
```
sudo apt-get install openjdk7
```