Ubuntu 12.10 安装 JDK 7u15官方版

1.打开官网，下载Java安装文件。

jdk-7u15-linux-x64.tar.gz

2.打开终端，根据个人习惯创建目录。

sudo mkdir /usr/local/development

3.把下载的文件移到这个文件夹和进行解压。使用以下命令：

sudo mv jdk-7u15-linux-x64.tar.gz /usr/local/development

sudo tar -zxvf jdk-7u15-linux-x64.tar.gz

4.修改环境变量

sudo gedit /etc/environment

源文件的内容如下：

PATH='/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games'

修订为：

PATH='/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games:/usr/local/games:${JAVA_HOME}/bin'

JAVA_HOME=/usr/local/development/jdk1.7.0_15

jre_HOME=${JAVA_HOME}/jre

CLASSPATH=.${JAVA_HOME}/lib:${JRE_HOME}/lib'

5.重新加载bashrc

source ~/.bashrc

6.配置默认JDK

sudo update-alternatives --install /usr/bin/java java /usr/local/development/jdk1.7.0_15/bin/java 300

sudo update-alternatives --install /usr/bin/javac javac /usr/local/development/jdk1.7.0_15/bin/javac 300

sudo update-alternatives --install /usr/bin/javap javap /usr/local/development/jdk1.7.0_15/bin/javap 300

sudo update-alternatives --install /usr/bin/javadoc javadoc /usr/local/development/jdk1.7.0_15/bin/javadoc 300

7.测试：

java -version

以下显示表明配置成功：

arlen@Arlen-TOP2:~$ java -version

java version '1.7.0_15'

Java(TM) SE Runtime Environment (build 1.7.0_15-b03)

Java HotSpot(TM) 64-Bit Server VM (build 23.7-b01, mixed mode)

arlen@Arlen-TOP2:~$