http://topspeedsnail.com/ubuntu16-install-java-jdk/

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Ubuntu 16.04安装Java JDK

Java JDK有两个版本，一个开源版本Openjdk，还有一个oracle官方版本jdk。下面记录在Ubuntu 16.04上安装Java JDK的步骤。

安装openjdk

更新软件包列表：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo apt-get update

</figure>

安装openjdk-8-jdk：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo apt-get install openjdk-8-jdk

</figure>

查看java版本：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ java -version

</figure>

java Ubuntu 16.04

安装oracle Java JDK

首先，安装依赖包：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo apt-get install python-software-properties

</figure>

添加仓库源：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo add-apt-repository ppa:webupd8team/java

</figure>

更新软件包列表：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo apt-get update

</figure>

安装java JDK：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo apt-get install oracle-java8-installer

</figure>

安装过程中需要接受协议：

java Ubuntu 16.04

查看java版本：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ java -version

</figure>

java Ubuntu 16.04

---

如果你同时安装了以上两个版本，你可以自由的在这两个版本之间切换。执行：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo update-alternatives --config java

</figure>

java Ubuntu 16.04

前面带星号的是当前正在使用的java版本，键入编号选择使用哪个版本。

编辑/etc/profile，在文件尾添加java环境变量：

<figure class="highlight" style="box-sizing: border-box; margin: 20px 0px; padding: 7px 7px 7px 10px; border: 1px solid rgb(221, 221, 221); font-style: inherit; font-variant: inherit; font-weight: inherit; font-stretch: inherit; font-size: inherit; line-height: inherit; font-family: inherit; vertical-align: baseline; display: block; background-color: rgb(239, 239, 239); box-shadow: rgba(0, 0, 0, 0.0980392) 3px 3px; overflow: scroll;">

$ sudo vim /etc/profile

</figure>

＃ 如果使用oracle java
export JAVA_HOME="/usr/lib/jvm/java-8-oracle/jre/bin"

# 如果使用openjdk
export JAVA_HOME="/usr/lib/jvm/java-8-openjdk-amd64/jre/bin"

OK，在Ubuntu 16.04上安装java完成。