Linux 学习之安装JDK

[Jim]

直接下载jdk压缩包方式安装

分为下面5个步骤

1. 官网下载JDK
2. 解压缩,放到指定目录
3. 配置环境变量
4. 设置系统默认JDK
5. 测试JDK

1.官网下载JDK

网址: http://www.oracle.com/technetwork/articles/javase/index-jsp-138363.html
选择相应的 .gz包下载 (这里我选择了"jdk-8u92-linux-i586.tar.gz")

2.解压缩,放到指定目录(以jdk-8u92-linux-i586.tar.gz为例)

1. 创建目录
   sudo mkdir /home/kumho/usr/lib/jvm
2. 解压文件至目录
   sudo tar -zxvf jdk-8u92-linux-i586.tar.gz -C /home/kumho/usr/lib/jvm

3. 修改环境变量

sudo vim ~/.bashrc
文件的末尾追加下面内容:

#set oracle jdk environment 
export JAVA_HOME=/home/kumho/usr/lib/jvm/jdk1.8.0_92  ##这里要注意目录要换成自己解压的jdk 目录
export JRE_HOME=${JAVA_HOME}/jre 
export CLASSPATH=.:${JAVA_HOME}/lib:${JRE_HOME}/lib
export PATH=${JAVA_HOME}/bin:$PATH

使环境变量马上生效source ~/.bashrc

4.设置系统默认jdk 版本

sudo update-alternatives --install /usr/bin/java java /home/kumho/usr/lib/jvm/jdk1.8.0_92/bin/java 300
sudo update-alternatives --install /usr/bin/javac javac /home/kumho/usr/lib/jvm/jdk1.8.0_92/bin/javac 300
sudo update-alternatives --install /usr/bin/jar jar /home/kumho/usr/lib/jvm/jdk1.8.0_92/bin/jar 300
sudo update-alternatives --install /usr/bin/javah javah /home/kumho/usr/lib/jvm/jdk1.8.0_92/bin/javah 300
sudo update-alternatives --install /usr/bin/javap javap /home/kumho/usr/lib/jvm/jdk1.8.0_92/bin/javap 300

然后执行:
sudo update-alternatives --config java
若是初次安装jdk,会有下面的提示
There is only one alternative in link group java (providing /usr/bin/java):
/home/kumho/usr/lib/jvm/jdk1.8.0_92/bin/java
否则,选择合适的jdk

5.测试jdk